[ { "path": ".gitattributes", "content": "*.t linguist-language=Text\n" }, { "path": ".github/ISSUE_TEMPLATE.md", "content": "This place is for bug reports and development discussions only. For general questions and\ndiscussions, please join the openresty-en mailing list instead: https://openresty.org/en/community.html\n\nEnsure you have provided the following details while reporting a problem:\n\n* The exact version of the related software, including but not limited to the OpenResty version\n(if any), the NGINX core version, the `ngx_lua` module version,\nand your operating system version.\n* A minimal and standalone test case that others can easily run on their side and\nreproduce the issue you are seeing.\n* Do not simply say \"something is broken\" or \"something does not work\". Always provide\nas much details as possible. Always describe the symptoms and your expected results.\n* You can (temporarily) enable the nginx debugging logs to see the internal workings\nof NGINX in your nginx''s `error.log` file. See http://nginx.org/en/docs/debugging_log.html\nThe same instructions apply equally well to OpenResty.\n* If you are seeing crashes, please provide the full backtrace for the crash. See\nhttps://www.nginx.com/resources/wiki/start/topics/tutorials/debugging/#core-dump\nfor more details.\n\nPlease, do not use Chinese here. This place is considered English only. If you\nreally want to use Chinese, please join and post to the openresty (Chinese)\nmailing list instead. Please see https://openresty.org/en/community.html Thanks for\nyour cooperation.\n" }, { "path": ".github/PULL_REQUEST_TEMPLATE.md", "content": "I hereby granted the copyright of the changes in this pull request\nto the authors of this lua-nginx-module project.\n" }, { "path": ".github/workflows/build_and_test.yml", "content": "name: Build and test\n\non:\n push:\n branches: [ master ]\n pull_request:\n branches: [ master ]\n\njobs:\n test:\n name: ${{ matrix.name }}\n runs-on: ubuntu-latest\n\n strategy:\n fail-fast: false\n matrix:\n include:\n - name: \"nginx 1.29.4 + OpenSSL\"\n NGINX_VERSION: \"1.29.4\"\n TEST_NGINX_TIMEOUT: \"5\"\n\n - name: \"nginx 1.29.4 + OpenSSL + HTTP/2\"\n NGINX_VERSION: \"1.29.4\"\n TEST_NGINX_TIMEOUT: \"5\"\n TEST_NGINX_USE_HTTP2: \"1\"\n\n - name: \"nginx 1.29.4 + OpenSSL + HTTP/3\"\n NGINX_VERSION: \"1.29.4\"\n TEST_NGINX_USE_HTTP3: \"1\"\n TEST_NGINX_QUIC_IDLE_TIMEOUT: \"3\"\n\n - name: \"nginx 1.29.4 + BoringSSL + HTTP/3\"\n NGINX_VERSION: \"1.29.4\"\n BORINGSSL: \"1\"\n TEST_NGINX_USE_HTTP3: \"1\"\n TEST_NGINX_QUIC_IDLE_TIMEOUT: \"3\"\n\n services:\n redis:\n image: redis:7-alpine\n ports:\n - 6379:6379\n mysql:\n image: mysql:8.0\n env:\n MYSQL_ALLOW_EMPTY_PASSWORD: yes\n ports:\n - 3306:3306\n options: >-\n --health-cmd=\"mysqladmin ping --silent\"\n --health-interval=10s\n --health-timeout=5s\n --health-retries=10\n\n env:\n JOBS: 3\n NGX_BUILD_JOBS: 3\n CC: gcc\n DRIZZLE_VER: \"2011.07.21\"\n LUAJIT_PREFIX: /opt/luajit21\n LUAJIT_LIB: /opt/luajit21/lib\n LUAJIT_INC: /opt/luajit21/include/luajit-2.1\n LUA_INCLUDE_DIR: /opt/luajit21/include/luajit-2.1\n PCRE2_PREFIX: /usr/local/openresty/pcre2\n PCRE2_LIB: /usr/local/openresty/pcre2/lib\n PCRE2_INC: /usr/local/openresty/pcre2/include\n OPENSSL_PREFIX: /usr/local/openresty/openssl3\n OPENSSL_LIB: /usr/local/openresty/openssl3/lib\n OPENSSL_INC: /usr/local/openresty/openssl3/include\n LIBDRIZZLE_PREFIX: /opt/drizzle\n LIBDRIZZLE_INC: /opt/drizzle/include/libdrizzle-1.0\n LIBDRIZZLE_LIB: /opt/drizzle/lib\n TEST_NGINX_SLEEP: \"0.006\"\n TEST_NGINX_SKIP_COSOCKET_LOG_TEST: \"1\"\n MALLOC_PERTURB_: \"9\"\n\n steps:\n - uses: actions/checkout@v4\n\n - name: Install system packages\n run: |\n sudo apt-get update -q\n sudo DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends \\\n ack axel cpanminus \\\n libtest-base-perl libtext-diff-perl liburi-perl libwww-perl \\\n libtest-longstring-perl liblist-moreutils-perl \\\n libgd-dev time cmake libunwind-dev wget \\\n libbrotli1 lsb-release gnupg ca-certificates dnsutils\n\n - name: Install Perl test modules\n run: |\n /usr/bin/env perl $(command -v cpanm) --sudo --notest \\\n Test::Nginx IPC::Run Test2::Util > build.log 2>&1 || (cat build.log && exit 1)\n\n - name: Add OpenResty apt repository\n run: |\n wget -qO- https://openresty.org/package/pubkey.gpg | gpg --dearmor | sudo tee /usr/share/keyrings/openresty.gpg > /dev/null\n echo \"deb [signed-by=/usr/share/keyrings/openresty.gpg] https://openresty.org/package/ubuntu $(lsb_release -sc) main\" \\\n | sudo tee /etc/apt/sources.list.d/openresty.list\n sudo apt-get update -q\n sudo DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends \\\n openresty-pcre2 openresty-openssl3 openresty-pcre2-dev openresty-openssl3-dev\n\n - name: Cache download directory\n uses: actions/cache@v4\n with:\n path: download-cache\n key: download-cache-${{ runner.os }}-drizzle-${{ env.DRIZZLE_VER }}\n\n - name: Source code style check\n run: |\n ! grep -n -P '(?<=.{80}).+' --color $(find src -name '*.c') $(find . -name '*.h') \\\n || (echo \"ERROR: Found C source lines exceeding 80 columns.\" >&2; exit 1)\n ! grep -n -P '\\t+' --color $(find src -name '*.c') $(find . -name '*.h') \\\n || (echo \"ERROR: Cannot use tabs.\" >&2; exit 1)\n\n - name: Clone dependency repositories\n run: |\n # Sibling repos — build scripts reference them via $root/../\n git clone --depth=1 https://github.com/openresty/openresty.git ../openresty\n git clone --depth=1 https://github.com/openresty/no-pool-nginx.git ../no-pool-nginx\n git clone --depth=1 https://github.com/openresty/lua-upstream-nginx-module.git ../lua-upstream-nginx-module\n git clone --depth=1 https://github.com/openresty/echo-nginx-module.git ../echo-nginx-module\n git clone --depth=1 https://github.com/openresty/nginx-eval-module.git ../nginx-eval-module\n git clone --depth=1 https://github.com/simpl/ngx_devel_kit.git ../ndk-nginx-module\n git clone --depth=1 https://github.com/FRiCKLE/ngx_coolkit.git ../coolkit-nginx-module\n git clone --depth=1 https://github.com/openresty/headers-more-nginx-module.git ../headers-more-nginx-module\n git clone --depth=1 https://github.com/openresty/drizzle-nginx-module.git ../drizzle-nginx-module\n git clone --depth=1 https://github.com/openresty/set-misc-nginx-module.git ../set-misc-nginx-module\n git clone --depth=1 https://github.com/openresty/memc-nginx-module.git ../memc-nginx-module\n git clone --depth=1 https://github.com/openresty/rds-json-nginx-module.git ../rds-json-nginx-module\n git clone --depth=1 https://github.com/openresty/srcache-nginx-module.git ../srcache-nginx-module\n git clone --depth=1 https://github.com/openresty/redis2-nginx-module.git ../redis2-nginx-module\n git clone --depth=1 https://github.com/openresty/lua-resty-core.git ../lua-resty-core\n git clone --depth=1 https://github.com/openresty/lua-resty-lrucache.git ../lua-resty-lrucache\n git clone --depth=1 https://github.com/openresty/lua-resty-mysql.git ../lua-resty-mysql\n git clone --depth=1 https://github.com/spacewander/lua-resty-rsa.git ../lua-resty-rsa\n git clone --depth=1 https://github.com/openresty/lua-resty-string.git ../lua-resty-string\n git clone --depth=1 https://github.com/openresty/stream-lua-nginx-module.git ../stream-lua-nginx-module\n\n # Local repos — used directly from the working directory\n git clone --depth=1 https://github.com/openresty/test-nginx.git\n git clone --depth=1 https://github.com/openresty/openresty-devel-utils.git\n git clone --depth=1 https://github.com/openresty/mockeagain.git\n git clone --depth=1 https://github.com/openresty/lua-cjson.git lua-cjson\n git clone -b v2.1-agentzh --depth=1 https://github.com/openresty/luajit2.git luajit2\n\n - name: Download prebuilt tarballs\n run: |\n mkdir -p download-cache\n if [ ! -f download-cache/drizzle7-$DRIZZLE_VER.tar.gz ]; then\n wget -P download-cache \\\n https://github.com/openresty/openresty-deps-prebuild/releases/download/v20230902/drizzle7-$DRIZZLE_VER.tar.gz\n fi\n wget https://github.com/openresty/openresty-deps-prebuild/releases/download/v20230902/boringssl-20230902-x64-focal.tar.gz\n wget https://github.com/openresty/openresty-deps-prebuild/releases/download/v20230902/curl-h3-x64-focal.tar.gz\n\n - name: Install curl-h3\n run: sudo tar -C / -xf curl-h3-x64-focal.tar.gz\n\n - name: Start memcached (native, UDP enabled)\n run: |\n sudo apt-get install -y --no-install-recommends memcached\n sudo systemctl stop memcached\n # Ubuntu's default /etc/memcached.conf has \"-U 0\" which disables UDP.\n # Start manually with UDP on port 11211 so udp-socket tests pass.\n memcached -d -l 127.0.0.1 -p 11211 -U 11211 -m 64\n sudo ss -lntup | grep 11211\n\n\n - name: Set up MySQL test database\n run: |\n mysql -h 127.0.0.1 -P 3306 -uroot \\\n -e \"CREATE DATABASE ngx_test; \\\n CREATE USER 'ngx_test'@'%' IDENTIFIED WITH mysql_native_password BY 'ngx_test'; \\\n GRANT ALL ON ngx_test.* TO 'ngx_test'@'%'; \\\n FLUSH PRIVILEGES;\"\n\n - name: Set up network rules\n run: |\n sudo iptables -I OUTPUT 1 -p udp --dport 10086 -j REJECT\n sudo iptables -I OUTPUT -p tcp --dst 127.0.0.2 --dport 12345 -j DROP\n sudo iptables -I OUTPUT -p udp --dst 127.0.0.2 --dport 12345 -j DROP\n sudo ip route add prohibit 0.0.0.1/32\n sudo sysctl -w kernel.pid_max=10000\n\n - name: Build LuaJIT\n run: |\n cd luajit2\n make -j$JOBS CCDEBUG=-g Q= PREFIX=$LUAJIT_PREFIX CC=$CC \\\n XCFLAGS='-DLUA_USE_APICHECK -DLUA_USE_ASSERT -msse4.2' \\\n > build.log 2>&1 || (cat build.log && exit 1)\n sudo make install PREFIX=$LUAJIT_PREFIX > build.log 2>&1 || (cat build.log && exit 1)\n\n - name: Build drizzle7\n run: |\n tar xzf download-cache/drizzle7-$DRIZZLE_VER.tar.gz\n cd drizzle7-$DRIZZLE_VER\n ./configure --prefix=$LIBDRIZZLE_PREFIX --without-server \\\n > build.log 2>&1 || (cat build.log && exit 1)\n make libdrizzle-1.0 -j$JOBS > build.log 2>&1 || (cat build.log && exit 1)\n sudo make install-libdrizzle-1.0 > build.log 2>&1 || (cat build.log && exit 1)\n\n - name: Build mockeagain\n run: cd mockeagain && make CC=$CC -j$JOBS\n\n - name: Build lua-cjson\n run: cd lua-cjson && make -j$JOBS && sudo make install\n\n - name: Set up BoringSSL\n if: matrix.BORINGSSL == '1'\n run: |\n sudo rm -fr $OPENSSL_PREFIX\n sudo mkdir -p $OPENSSL_PREFIX\n sudo tar -C $OPENSSL_PREFIX -xf boringssl-20230902-x64-focal.tar.gz --strip-components=1\n\n - name: Build nginx\n run: |\n export LD_LIBRARY_PATH=$LUAJIT_LIB:$LD_LIBRARY_PATH\n export PATH=$PWD/work/nginx/sbin:$PWD/openresty-devel-utils:/opt/curl-h3/bin:$PATH\n export NGX_BUILD_CC=$CC\n sh util/build-without-ssl.sh ${{ matrix.NGINX_VERSION }} > build.log 2>&1 || (cat build.log && exit 1)\n sh util/build-with-dd.sh ${{ matrix.NGINX_VERSION }} > build.log 2>&1 || (cat build.log && exit 1)\n rm -fr buildroot\n sh util/build.sh ${{ matrix.NGINX_VERSION }} > build.log 2>&1 || (cat build.log && exit 1)\n nginx -V\n ldd $(which nginx) | grep -E 'luajit|ssl|pcre'\n\n - name: Run releng check\n run: |\n export PATH=$PWD/work/nginx/sbin:$PWD/openresty-devel-utils:/opt/curl-h3/bin:$PATH\n ngx-releng > check.txt || true\n lines=$(wc -l check.txt | awk '{print $1}')\n if [ \"$lines\" -gt 5 ]; then cat check.txt; exit 1; fi\n\n - name: Set matrix-specific test env vars\n run: |\n # Only export vars that have actual values — Perl's defined() treats\n # empty strings as defined, which would cause false positives in tests\n # like t/103-req-http-ver.t that branch on defined $ENV{TEST_NGINX_USE_HTTP3}.\n [ -n \"${{ matrix.TEST_NGINX_TIMEOUT }}\" ] \\\n && echo \"TEST_NGINX_TIMEOUT=${{ matrix.TEST_NGINX_TIMEOUT }}\" >> $GITHUB_ENV || true\n [ -n \"${{ matrix.TEST_NGINX_USE_HTTP2 }}\" ] \\\n && echo \"TEST_NGINX_USE_HTTP2=${{ matrix.TEST_NGINX_USE_HTTP2 }}\" >> $GITHUB_ENV || true\n [ -n \"${{ matrix.TEST_NGINX_USE_HTTP3 }}\" ] \\\n && echo \"TEST_NGINX_USE_HTTP3=${{ matrix.TEST_NGINX_USE_HTTP3 }}\" >> $GITHUB_ENV || true\n [ -n \"${{ matrix.TEST_NGINX_QUIC_IDLE_TIMEOUT }}\" ] \\\n && echo \"TEST_NGINX_QUIC_IDLE_TIMEOUT=${{ matrix.TEST_NGINX_QUIC_IDLE_TIMEOUT }}\" >> $GITHUB_ENV || true\n\n - name: Run tests\n run: |\n export LD_LIBRARY_PATH=$LUAJIT_LIB:$PWD/mockeagain:$LD_LIBRARY_PATH\n export PATH=$PWD/work/nginx/sbin:$PWD/openresty-devel-utils:/opt/curl-h3/bin:$PATH\n export LD_PRELOAD=$PWD/mockeagain/mockeagain.so\n export TEST_NGINX_HTTP3_CRT=$PWD/t/cert/http3/http3.crt\n export TEST_NGINX_HTTP3_KEY=$PWD/t/cert/http3/http3.key\n export TEST_NGINX_RESOLVER=8.8.4.4\n dig +short myip.opendns.com @resolver1.opendns.com || exit 0\n dig +short @$TEST_NGINX_RESOLVER openresty.org || exit 0\n dig +short @$TEST_NGINX_RESOLVER agentzh.org || exit 0\n python3 ./util/nc_server.py &\n /usr/bin/env perl $(command -v prove) -I. -Itest-nginx/inc -Itest-nginx/lib -r t/\n" }, { "path": ".github/workflows/semantic-pull-request.yml", "content": "name: \"Lint PR\"\n\non:\n pull_request_target:\n types:\n - opened\n - edited\n - synchronize\n\njobs:\n main:\n name: Validate PR title\n runs-on: ubuntu-latest\n steps:\n - uses: amannn/action-semantic-pull-request@v4\n env:\n GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}\n with:\n # Configure which types are allowed.\n # Default: https://github.com/commitizen/conventional-commit-types\n types: |\n bugfix # bug fixes\n change # backward incompatible changes\n doc # documentation changes including code comments\n editor # code editor related configurations\n feature # implementing a new feature\n optimize # performance optimizations\n refactor # code refactoring and other code rearrangement\n style # coding style changes\n tests # test suite changes\n" }, { "path": ".gitignore", "content": "build/\nwork/\ntags\ncscope.*\n*.mobi\ngenmobi.sh\n.libs\n*.swp\n*.slo\n*.la\n*.swo\n*.lo\n*~\n*.o\nprint.txt\n.rsync\n*.tar.gz\ndist\nbuild[789]\nbuild\ntags\nupdate-readme\n*.tmp\ntest/Makefile\ntest/blib\ntest.sh\nt.sh\nt/t.sh\nt/servroot*\ntest/t/servroot/\nreleng\nreset\n*.t_\nsrc/handler.h\nsrc/util.c\nsrc/module.h\nsrc/module.c\nsrc/drizzle.c\nsrc/processor.h\nsrc/handler.c\nsrc/util.h\nsrc/drizzle.h\nsrc/processor.c\nsrc/output.c\nsrc/output.h\nlibdrizzle\nctags\nsrc/stream.h\nnginx\nkeepalive\nreindex\nsrc/keepalive.c\nsrc/keepalive.h\nsrc/checker.h\nsrc/checker.c\nsrc/quoting.h\nsrc/quoting.c\nsrc/module.h\nsrc/module.c\nsrc/util.h\nsrc/util.c\nsrc/processor.h\nsrc/processor.c\nsrc/rds.h\nsrc/utils.h\nsrc/handler.c\nsrc/handler.h\nutil/bench\n*.html\ntrace.out*\ntry.sh\nsrc/cache.c\nsrc/cache.h\nsrc/common.h\nsrc/directive.c\nsrc/directive.h\nsrc/consts.[ch]\nsrc/contentby.[ch]\nsrc/pcrefix.[ch]\nsrc/util.c\nsrc/clfactory.c\nsrc/directive.c\nsrc/conf.h\nsrc/setby.h\nsrc/cache.h\nsrc/hook.c\nsrc/util.h\nsrc/hook.h\nsrc/common.h\nsrc/directive.h\nsrc/conf.c\nsrc/setby.c\nsrc/cache.c\nsrc/module.c\nsrc/clfactory.h\nsrc/capturefilter.[ch]\nsrc/contentby.c\npack\nb.sh\nsrc/in.[ch]\nsrc/out.[ch]\ngo\nall.sh\nsrc/accessby.[ch]\nsrc/rewriteby.[ch]\nsrc/patch.[ch]\nsrc/ndk.[ch]\nsrc/control.[ch]\nsrc/output.[ch]\nsrc/variable.[ch]\nsrc/string.[ch]\nsrc/misc.[ch]\nsrc/log.[ch]\nsrc/exception.[ch]\nsrc/subrequest.[ch]\nsrc/time.[ch]\nsrc/regex.[ch]\nsrc/ctx.[ch]\nsrc/args.[ch]\nsrc/headers.[ch]\nsrc/script.[ch]\nsrc/filter.[ch]\nsrc/shdict.[ch]\nsrc/body.[ch]\nsrc/uri.[ch]\nsrc/api.[ch]\nsrc/coroutine.[ch]\nsrc/logby.[ch]\nsrc/sleep.[ch]\na.patch\nall\nbuild1[0-9]\ng\nbuildroot/\nsrc/headerfilterby.[ch]\n*.patch\nanalyze\ntsock\na.c\ntest.lua\nbuild12\nERRORS\nsrc/bodyfilterby.[ch]\nsrc/tcp.[ch]\nsrc/initby.[ch]\nsrc/initworkerby.[ch]\nsrc/socket.[ch]\nsrc/udp.[ch]\nsrc/method.[ch]\ntre\nsrc/phase.[ch]\nsrc/probe.h\nsrc/uthread.[ch]\nsrc/timer.[ch]\nsrc/config.[ch]\nsrc/worker.[ch]\nsrc/certby.[ch]\nsrc/storeby.[ch]\nsrc/fetchby.[ch]\nsrc/ssl.[ch]\nsrc/ocsp.c\nsrc/lex.[ch]\nsrc/balancer.[ch]\nsrc/semaphore.[ch]\n*.plist\nlua\nttimer\nMakefile\ntsubreq\ntthread\naddr2line\nhup\ntheaders\nsrc/ngx_http_lua_autoconf.h\nsrc/autoconf.h\nsrc/filters.c\nsrc/filters.h\nsrc/ringbuf.c\nsrc/ringbuf.h\nsrc/pipe.[ch]\n" }, { "path": ".mergify.yml", "content": "---\npull_request_rules:\n - name: warn on conflicts\n conditions:\n - conflict\n actions:\n comment:\n message: This pull request is now in conflict :(\n label:\n add:\n - conflict\n - name: remove conflict label if not needed\n conditions:\n - -conflict\n actions:\n label:\n remove:\n - conflict\n - name: add label needs-test-cases\n conditions:\n - files~=^src/\n - -files~=^t/\n actions:\n label:\n add:\n - needs-test-cases\n - name: remove label needs-test-cases\n conditions:\n - label=needs-test-cases\n - files~=^src/\n - files~=^t/\n actions:\n label:\n remove:\n - needs-test-cases\n - name: add label could-be-merged\n conditions:\n - \"#approved-reviews-by>=2\"\n - status-success=Travis CI - Pull Request\n actions:\n label:\n add:\n - could-be-merged\n" }, { "path": "README.markdown", "content": "Name\n====\n\nngx_http_lua_module - Embed the power of Lua into Nginx HTTP Servers.\n\nThis module is a core component of [OpenResty](https://openresty.org). If you are using this module,\nthen you are essentially using OpenResty :)\n\n*This module is not distributed with the Nginx source.* See\n[the installation instructions](#installation).\n\nTable of Contents\n=================\n\n* [Name](#name)\n* [Status](#status)\n* [Version](#version)\n* [Videos](#videos)\n* [Synopsis](#synopsis)\n* [Description](#description)\n* [Typical Uses](#typical-uses)\n* [Nginx Compatibility](#nginx-compatibility)\n* [Installation](#installation)\n * [Building as a dynamic module](#building-as-a-dynamic-module)\n * [C Macro Configurations](#c-macro-configurations)\n* [Community](#community)\n * [English Mailing List](#english-mailing-list)\n * [Chinese Mailing List](#chinese-mailing-list)\n* [Code Repository](#code-repository)\n* [Bugs and Patches](#bugs-and-patches)\n* [LuaJIT bytecode support](#luajit-bytecode-support)\n* [System Environment Variable Support](#system-environment-variable-support)\n* [HTTP 1.0 support](#http-10-support)\n* [Statically Linking Pure Lua Modules](#statically-linking-pure-lua-modules)\n* [Data Sharing within an Nginx Worker](#data-sharing-within-an-nginx-worker)\n* [Known Issues](#known-issues)\n * [TCP socket connect operation issues](#tcp-socket-connect-operation-issues)\n * [Lua Coroutine Yielding/Resuming](#lua-coroutine-yieldingresuming)\n * [Lua Variable Scope](#lua-variable-scope)\n * [Locations Configured by Subrequest Directives of Other Modules](#locations-configured-by-subrequest-directives-of-other-modules)\n * [Cosockets Not Available Everywhere](#cosockets-not-available-everywhere)\n * [Special Escaping Sequences](#special-escaping-sequences)\n * [Mixing with SSI Not Supported](#mixing-with-ssi-not-supported)\n * [SPDY Mode Not Fully Supported](#spdy-mode-not-fully-supported)\n * [Missing data on short circuited requests](#missing-data-on-short-circuited-requests)\n* [TODO](#todo)\n* [Changes](#changes)\n* [Build And Test](#build-and-test)\n* [Test Suite](#test-suite)\n* [Copyright and License](#copyright-and-license)\n* [See Also](#see-also)\n* [Directives](#directives)\n* [Nginx API for Lua](#nginx-api-for-lua)\n* [Obsolete Sections](#obsolete-sections)\n * [Special PCRE Sequences](#special-pcre-sequences)\n * [Lua/LuaJIT bytecode support](#lualuajit-bytecode-support)\n\nStatus\n======\n\nProduction ready.\n\nVersion\n=======\n\nThis document describes ngx_lua\n[v0.10.29](https://github.com/openresty/lua-nginx-module/tags), which was released\non Oct 24, 2025.\n\nVideos\n======\n\n* YouTube video \"[Hello World HTTP Example with OpenResty/Lua](https://youtu.be/eSfYLvVQMxw)\"\n\n [![Hello World HTTP Example with OpenResty/Lua](https://img.youtube.com/vi/eSfYLvVQMxw/0.jpg)](https://youtu.be/eSfYLvVQMxw)\n\n* YouTube video \"[Write Your Own Lua Modules in OpenResty/Nginx Applications](https://youtu.be/vfYxOMl5LVY)\"\n\n [![Write Your Own Lua Modules in OpenResty/Nginx Applications](https://img.youtube.com/vi/vfYxOMl5LVY/0.jpg)](https://youtu.be/vfYxOMl5LVY)\n\n* YouTube video \"[OpenResty's resty Command-Line Utility Demo](https://youtu.be/L1c7aw4mSOo)\"\n\n [![OpenResty's resty Command-Line Utility Demo](https://img.youtube.com/vi/L1c7aw4mSOo/0.jpg)](https://youtu.be/L1c7aw4mSOo)\n\n* YouTube video \"[Measure Execution Time of Lua Code Correctly in OpenResty](https://youtu.be/VkRYW_qLoME)\"\n\n [![Measure Execution Time of Lua Code Correctly in OpenResty](https://img.youtube.com/vi/VkRYW_qLoME/0.jpg)](https://youtu.be/VkRYW_qLoME)\n\n* YouTube video \"[Precompile Lua Modules into LuaJIT Bytecode to Speedup OpenResty Startup](https://youtu.be/EP7c0BM2yNo)\"\n\n [![Precompile Lua Modules into LuaJIT Bytecode to Speedup OpenResty Startup](https://img.youtube.com/vi/EP7c0BM2yNo/0.jpg)](https://youtu.be/EP7c0BM2yNo)\n\nYou are welcome to subscribe to our [official YouTube channel, OpenResty](https://www.youtube.com/channel/UCXVmwF-UCScv2ftsGoMqxhw).\n\n[Back to TOC](#table-of-contents)\n\nSynopsis\n========\n```nginx\n\n # set search paths for pure Lua external libraries (';;' is the default path):\n lua_package_path '/foo/bar/?.lua;/blah/?.lua;;';\n\n # set search paths for Lua external libraries written in C (can also use ';;'):\n lua_package_cpath '/bar/baz/?.so;/blah/blah/?.so;;';\n\n server {\n location /lua_content {\n # MIME type determined by default_type:\n default_type 'text/plain';\n\n content_by_lua_block {\n ngx.say('Hello,world!')\n }\n }\n\n location /nginx_var {\n # MIME type determined by default_type:\n default_type 'text/plain';\n\n # try access /nginx_var?a=hello,world\n content_by_lua_block {\n ngx.say(ngx.var.arg_a)\n }\n }\n\n location = /request_body {\n client_max_body_size 50k;\n client_body_buffer_size 50k;\n\n content_by_lua_block {\n ngx.req.read_body() -- explicitly read the req body\n local data = ngx.req.get_body_data()\n if data then\n ngx.say(\"body data:\")\n ngx.print(data)\n return\n end\n\n -- body may get buffered in a temp file:\n local file = ngx.req.get_body_file()\n if file then\n ngx.say(\"body is in file \", file)\n else\n ngx.say(\"no body found\")\n end\n }\n }\n\n # transparent non-blocking I/O in Lua via subrequests\n # (well, a better way is to use cosockets)\n location = /lua {\n # MIME type determined by default_type:\n default_type 'text/plain';\n\n content_by_lua_block {\n local res = ngx.location.capture(\"/some_other_location\")\n if res then\n ngx.say(\"status: \", res.status)\n ngx.say(\"body:\")\n ngx.print(res.body)\n end\n }\n }\n\n location = /foo {\n rewrite_by_lua_block {\n res = ngx.location.capture(\"/memc\",\n { args = { cmd = \"incr\", key = ngx.var.uri } }\n )\n }\n\n proxy_pass http://blah.blah.com;\n }\n\n location = /mixed {\n rewrite_by_lua_file /path/to/rewrite.lua;\n access_by_lua_file /path/to/access.lua;\n content_by_lua_file /path/to/content.lua;\n }\n\n # use nginx var in code path\n # CAUTION: contents in nginx var must be carefully filtered,\n # otherwise there'll be great security risk!\n location ~ ^/app/([-_a-zA-Z0-9/]+) {\n set $path $1;\n content_by_lua_file /path/to/lua/app/root/$path.lua;\n }\n\n location / {\n client_max_body_size 100k;\n client_body_buffer_size 100k;\n\n access_by_lua_block {\n -- check the client IP address is in our black list\n if ngx.var.remote_addr == \"132.5.72.3\" then\n ngx.exit(ngx.HTTP_FORBIDDEN)\n end\n\n -- check if the URI contains bad words\n if ngx.var.uri and\n string.match(ngx.var.request_body, \"evil\")\n then\n return ngx.redirect(\"/terms_of_use.html\")\n end\n\n -- tests passed\n }\n\n # proxy_pass/fastcgi_pass/etc settings\n }\n }\n```\n\n[Back to TOC](#table-of-contents)\n\nDescription\n===========\n\nThis module embeds [LuaJIT 2.0/2.1](https://luajit.org/luajit.html) into Nginx.\nIt is a core component of [OpenResty](https://openresty.org). If you are using\nthis module, then you are essentially using OpenResty.\n\nSince version `v0.10.16` of this module, the standard Lua\ninterpreter (also known as \"PUC-Rio Lua\") is not supported anymore. This\ndocument interchangeably uses the terms \"Lua\" and \"LuaJIT\" to refer to the\nLuaJIT interpreter.\n\nBy leveraging Nginx's subrequests, this module allows the integration of the\npowerful Lua threads (known as Lua \"coroutines\") into the Nginx event model.\n\nUnlike [Apache's mod_lua](https://httpd.apache.org/docs/trunk/mod/mod_lua.html)\nand [Lighttpd's mod_magnet](http://redmine.lighttpd.net/wiki/1/Docs:ModMagnet),\nLua code executed using this module can be *100% non-blocking* on network\ntraffic as long as the [Nginx API for Lua](#nginx-api-for-lua) provided by\nthis module is used to handle requests to upstream services such as MySQL,\nPostgreSQL, Memcached, Redis, or upstream HTTP web services.\n\nAt least the following Lua libraries and Nginx modules can be used with this\nmodule:\n\n* [lua-resty-memcached](https://github.com/openresty/lua-resty-memcached)\n* [lua-resty-mysql](https://github.com/openresty/lua-resty-mysql)\n* [lua-resty-redis](https://github.com/openresty/lua-resty-redis)\n* [lua-resty-dns](https://github.com/openresty/lua-resty-dns)\n* [lua-resty-upload](https://github.com/openresty/lua-resty-upload)\n* [lua-resty-websocket](https://github.com/openresty/lua-resty-websocket)\n* [lua-resty-lock](https://github.com/openresty/lua-resty-lock)\n* [lua-resty-logger-socket](https://github.com/cloudflare/lua-resty-logger-socket)\n* [lua-resty-lrucache](https://github.com/openresty/lua-resty-lrucache)\n* [lua-resty-string](https://github.com/openresty/lua-resty-string)\n* [ngx_memc](http://github.com/openresty/memc-nginx-module)\n* [ngx_postgres](https://github.com/FRiCKLE/ngx_postgres)\n* [ngx_redis2](http://github.com/openresty/redis2-nginx-module)\n* [ngx_redis](http://wiki.nginx.org/HttpRedisModule)\n* [ngx_proxy](http://nginx.org/en/docs/http/ngx_http_proxy_module.html)\n* [ngx_fastcgi](http://nginx.org/en/docs/http/ngx_http_fastcgi_module.html)\n\nAlmost any Nginx modules can be used with this ngx_lua module by means of\n[ngx.location.capture](#ngxlocationcapture) or\n[ngx.location.capture_multi](#ngxlocationcapture_multi) but it is\nrecommended to use those `lua-resty-*` libraries instead of creating\nsubrequests to access the Nginx upstream modules because the former is usually\nmuch more flexible and memory-efficient.\n\nThe Lua interpreter (also known as \"Lua State\" or \"LuaJIT VM instance\") is\nshared across all the requests in a single Nginx worker process to minimize\nmemory use. Request contexts are segregated using lightweight Lua coroutines.\n\nLoaded Lua modules persist in the Nginx worker process level resulting in a\nsmall memory footprint in Lua even when under heavy loads.\n\nThis module is plugged into Nginx's \"http\" subsystem so it can only speak\ndownstream communication protocols in the HTTP family (HTTP 0.9/1.0/1.1/2.0,\nWebSockets, etc...). If you want to do generic TCP communications with the\ndownstream clients, then you should use the\n[ngx_stream_lua](https://github.com/openresty/stream-lua-nginx-module#readme)\nmodule instead, which offers a compatible Lua API.\n\n[Back to TOC](#table-of-contents)\n\nTypical Uses\n============\n\nJust to name a few:\n\n* Mashup'ing and processing outputs of various Nginx upstream outputs (proxy, drizzle, postgres, redis, memcached, etc.) in Lua,\n* doing arbitrarily complex access control and security checks in Lua before requests actually reach the upstream backends,\n* manipulating response headers in an arbitrary way (by Lua)\n* fetching backend information from external storage backends (like redis, memcached, mysql, postgresql) and use that information to choose which upstream backend to access on-the-fly,\n* coding up arbitrarily complex web applications in a content handler using synchronous but still non-blocking access to the database backends and other storage,\n* doing very complex URL dispatch in Lua at rewrite phase,\n* using Lua to implement advanced caching mechanism for Nginx's subrequests and arbitrary locations.\n\nThe possibilities are unlimited as the module allows bringing together various\nelements within Nginx as well as exposing the power of the Lua language to the\nuser. The module provides the full flexibility of scripting while offering\nperformance levels comparable with native C language programs both in terms of\nCPU time as well as memory footprint thanks to LuaJIT 2.x.\n\nOther scripting language implementations typically struggle to match this\nperformance level.\n\n[Back to TOC](#table-of-contents)\n\nNginx Compatibility\n===================\n\nThe latest version of this module is compatible with the following versions of Nginx:\n\n* 1.29.x (last tested: 1.29.2)\n* 1.27.x (last tested: 1.27.1)\n* 1.25.x (last tested: 1.25.1)\n* 1.21.x (last tested: 1.21.4)\n* 1.19.x (last tested: 1.19.3)\n* 1.17.x (last tested: 1.17.8)\n* 1.15.x (last tested: 1.15.8)\n* 1.14.x\n* 1.13.x (last tested: 1.13.6)\n* 1.12.x\n* 1.11.x (last tested: 1.11.2)\n* 1.10.x\n* 1.9.x (last tested: 1.9.15)\n* 1.8.x\n* 1.7.x (last tested: 1.7.10)\n* 1.6.x\n\nNginx cores older than 1.6.0 (exclusive) are *not* supported.\n\n[Back to TOC](#table-of-contents)\n\nInstallation\n============\n\nIt is *highly* recommended to use [OpenResty releases](https://openresty.org)\nwhich bundle Nginx, ngx_lua (this module), LuaJIT, as well as other powerful\ncompanion Nginx modules and Lua libraries.\n\nIt is discouraged to build this module with Nginx yourself since it is tricky\nto set up exactly right.\n\nNote that Nginx, LuaJIT, and OpenSSL official releases have various limitations\nand long-standing bugs that can cause some of this module's features to be\ndisabled, not work properly, or run slower. Official OpenResty releases are\nrecommended because they bundle [OpenResty's optimized LuaJIT 2.1 fork](https://github.com/openresty/luajit2) and\n[Nginx/OpenSSL\npatches](https://github.com/openresty/openresty/tree/master/patches).\n\nAlternatively, ngx_lua can be manually compiled into Nginx:\n\n1. LuaJIT can be downloaded from the [latest release of OpenResty's LuaJIT fork](https://github.com/openresty/luajit2/releases). The official LuaJIT 2.x releases are also supported, although performance will be significantly lower for reasons elaborated above\n1. Download the latest version of the ngx_devel_kit (NDK) module [HERE](https://github.com/simplresty/ngx_devel_kit/tags)\n1. Download the latest version of ngx_lua [HERE](https://github.com/openresty/lua-nginx-module/tags)\n1. Download the latest supported version of Nginx [HERE](https://nginx.org/) (See [Nginx Compatibility](#nginx-compatibility))\n1. Download the latest version of the lua-resty-core [HERE](https://github.com/openresty/lua-resty-core)\n1. Download the latest version of the lua-resty-lrucache [HERE](https://github.com/openresty/lua-resty-lrucache)\n\nBuild the source with this module:\n\n```bash\n\n wget 'https://openresty.org/download/nginx-1.19.3.tar.gz'\n tar -xzvf nginx-1.19.3.tar.gz\n cd nginx-1.19.3/\n\n # tell nginx's build system where to find LuaJIT 2.0:\n export LUAJIT_LIB=/path/to/luajit/lib\n export LUAJIT_INC=/path/to/luajit/include/luajit-2.0\n\n # tell nginx's build system where to find LuaJIT 2.1:\n export LUAJIT_LIB=/path/to/luajit/lib\n export LUAJIT_INC=/path/to/luajit/include/luajit-2.1\n\n # Here we assume Nginx is to be installed under /opt/nginx/.\n ./configure --prefix=/opt/nginx \\\n --with-ld-opt=\"-Wl,-rpath,/path/to/luajit/lib\" \\\n --add-module=/path/to/ngx_devel_kit \\\n --add-module=/path/to/lua-nginx-module\n\n # Note that you may also want to add `./configure` options which are used in your\n # current nginx build.\n # You can get usually those options using command nginx -V\n\n # you can change the parallelism number 2 below to fit the number of spare CPU cores in your\n # machine.\n make -j2\n make install\n\n # Note that this version of lug-nginx-module not allow to set `lua_load_resty_core off;` any more.\n # So, you have to install `lua-resty-core` and `lua-resty-lrucache` manually as below.\n\n cd lua-resty-core\n make install PREFIX=/opt/nginx\n cd lua-resty-lrucache\n make install PREFIX=/opt/nginx\n\n # add necessary `lua_package_path` directive to `nginx.conf`, in the http context\n\n lua_package_path \"/opt/nginx/lib/lua/?.lua;;\";\n```\n\n[Back to TOC](#table-of-contents)\n\nBuilding as a dynamic module\n----------------------------\n\nStarting from NGINX 1.9.11, you can also compile this module as a dynamic module, by using the `--add-dynamic-module=PATH` option instead of `--add-module=PATH` on the\n`./configure` command line above. And then you can explicitly load the module in your `nginx.conf` via the [load_module](https://nginx.org/en/docs/ngx_core_module.html#load_module)\ndirective, for example,\n\n```nginx\n\n load_module /path/to/modules/ndk_http_module.so; # assuming NDK is built as a dynamic module too\n load_module /path/to/modules/ngx_http_lua_module.so;\n```\n\n[Back to TOC](#table-of-contents)\n\nC Macro Configurations\n----------------------\n\nWhile building this module either via OpenResty or with the Nginx core, you can define the following C macros via the C compiler options:\n\n* `NGX_LUA_USE_ASSERT`\n\tWhen defined, will enable assertions in the ngx_lua C code base. Recommended for debugging or testing builds. It can introduce some (small) runtime overhead when enabled. This macro was first introduced in the `v0.9.10` release.\n* `NGX_LUA_ABORT_AT_PANIC`\n\tWhen the LuaJIT VM panics, ngx_lua will instruct the current nginx worker process to quit gracefully by default. By specifying this C macro, ngx_lua will abort the current nginx worker process (which usually results in a core dump file) immediately. This option is useful for debugging VM panics. This option was first introduced in the `v0.9.8` release.\n\nTo enable one or more of these macros, just pass extra C compiler options to the `./configure` script of either Nginx or OpenResty. For instance,\n\n\n ./configure --with-cc-opt=\"-DNGX_LUA_USE_ASSERT -DNGX_LUA_ABORT_AT_PANIC\"\n\n\n[Back to TOC](#table-of-contents)\n\nCommunity\n=========\n\n[Back to TOC](#table-of-contents)\n\nEnglish Mailing List\n--------------------\n\nThe [openresty-en](https://groups.google.com/group/openresty-en) mailing list is for English speakers.\n\n[Back to TOC](#table-of-contents)\n\nChinese Mailing List\n--------------------\n\nThe [openresty](https://groups.google.com/group/openresty) mailing list is for Chinese speakers.\n\n[Back to TOC](#table-of-contents)\n\nCode Repository\n===============\n\nThe code repository of this project is hosted on GitHub at\n[openresty/lua-nginx-module](https://github.com/openresty/lua-nginx-module).\n\n[Back to TOC](#table-of-contents)\n\nBugs and Patches\n================\n\nPlease submit bug reports, wishlists, or patches by\n\n1. creating a ticket on the [GitHub Issue Tracker](https://github.com/openresty/lua-nginx-module/issues),\n1. or posting to the [OpenResty community](#community).\n\n[Back to TOC](#table-of-contents)\n\nLuaJIT bytecode support\n=======================\n\nWatch YouTube video \"[Measure Execution Time of Lua Code Correctly in OpenResty](https://youtu.be/VkRYW_qLoME)\"\n\n[![Precompile Lua Modules into LuaJIT Bytecode to Speedup OpenResty Startup](https://img.youtube.com/vi/EP7c0BM2yNo/0.jpg)](https://youtu.be/EP7c0BM2yNo)\n\nAs from the `v0.5.0rc32` release, all `*_by_lua_file` configure directives (such as [content_by_lua_file](#content_by_lua_file)) support loading LuaJIT 2.0/2.1 raw bytecode files directly:\n\n```bash\n\n /path/to/luajit/bin/luajit -b /path/to/input_file.lua /path/to/output_file.ljbc\n```\n\nThe `-bg` option can be used to include debug information in the LuaJIT bytecode file:\n\n```bash\n\n /path/to/luajit/bin/luajit -bg /path/to/input_file.lua /path/to/output_file.ljbc\n```\n\nPlease refer to the official LuaJIT documentation on the `-b` option for more details:\n\n\n\nNote that the bytecode files generated by LuaJIT 2.1 is *not* compatible with\nLuaJIT 2.0, and vice versa. The support for LuaJIT 2.1 bytecode was first added\nin ngx_lua v0.9.3.\n\nAttempts to load standard Lua 5.1 bytecode files into ngx_lua instances linked\nto LuaJIT 2.0/2.1 (or vice versa) will result in an Nginx error message such as\nthe one below:\n\n\n [error] 13909#0: *1 failed to load Lua inlined code: bad byte-code header in /path/to/test_file.luac\n\n\nLoading bytecode files via the Lua primitives like `require` and\n`dofile` should always work as expected.\n\n[Back to TOC](#table-of-contents)\n\nSystem Environment Variable Support\n===================================\n\nIf you want to access the system environment variable, say, `foo`, in Lua via the standard Lua API [os.getenv](https://www.lua.org/manual/5.1/manual.html#pdf-os.getenv), then you should also list this environment variable name in your `nginx.conf` file via the [env directive](https://nginx.org/en/docs/ngx_core_module.html#env). For example,\n\n```nginx\n\n env foo;\n```\n\n[Back to TOC](#table-of-contents)\n\nHTTP 1.0 support\n================\n\nThe HTTP 1.0 protocol does not support chunked output and requires an explicit `Content-Length` header when the response body is not empty in order to support the HTTP 1.0 keep-alive.\nSo when a HTTP 1.0 request is made and the [lua_http10_buffering](#lua_http10_buffering) directive is turned `on`, ngx_lua will buffer the\noutput of [ngx.say](#ngxsay) and [ngx.print](#ngxprint) calls and also postpone sending response headers until all the response body output is received.\nAt that time ngx_lua can calculate the total length of the body and construct a proper `Content-Length` header to return to the HTTP 1.0 client.\nIf the `Content-Length` response header is set in the running Lua code, however, this buffering will be disabled even if the [lua_http10_buffering](#lua_http10_buffering) directive is turned `on`.\n\nFor large streaming output responses, it is important to disable the [lua_http10_buffering](#lua_http10_buffering) directive to minimise memory usage.\n\nNote that common HTTP benchmark tools such as `ab` and `http_load` issue HTTP 1.0 requests by default.\nTo force `curl` to send HTTP 1.0 requests, use the `-0` option.\n\n[Back to TOC](#table-of-contents)\n\nStatically Linking Pure Lua Modules\n===================================\n\nWith LuaJIT 2.x, it is possible to statically link the bytecode of pure Lua\nmodules into the Nginx executable.\n\nYou can use the `luajit` executable to compile `.lua` Lua\nmodule files to `.o` object files containing the exported bytecode\ndata, and then link the `.o` files directly in your Nginx build.\n\nBelow is a trivial example to demonstrate this. Consider that we have the following `.lua` file named `foo.lua`:\n\n```lua\n\n -- foo.lua\n local _M = {}\n\n function _M.go()\n print(\"Hello from foo\")\n end\n\n return _M\n```\n\nAnd then we compile this `.lua` file to `foo.o` file:\n\n```bash\n\n /path/to/luajit/bin/luajit -bg foo.lua foo.o\n```\n\nWhat matters here is the name of the `.lua` file, which determines how you use this module later on the Lua land. The file name `foo.o` does not matter at all except the `.o` file extension (which tells `luajit` what output format is used). If you want to strip the Lua debug information from the resulting bytecode, you can just specify the `-b` option above instead of `-bg`.\n\nThen when building Nginx or OpenResty, pass the `--with-ld-opt=\"foo.o\"` option to the `./configure` script:\n\n```bash\n\n ./configure --with-ld-opt=\"/path/to/foo.o\" ...\n```\n\nFinally, you can just do the following in any Lua code run by ngx_lua:\n\n```lua\n\n local foo = require \"foo\"\n foo.go()\n```\n\nAnd this piece of code no longer depends on the external `foo.lua` file any more because it has already been compiled into the `nginx` executable.\n\nIf you want to use dot in the Lua module name when calling `require`, as in\n\n```lua\n\n local foo = require \"resty.foo\"\n```\n\nthen you need to rename the `foo.lua` file to `resty_foo.lua` before compiling it down to a `.o` file with the `luajit` command-line utility.\n\nIt is important to use exactly the same version of LuaJIT when compiling `.lua` files to `.o` files as building nginx + ngx_lua. This is because the LuaJIT bytecode format may be incompatible between different LuaJIT versions. When the bytecode format is incompatible, you will see a Lua runtime error saying that the Lua module is not found.\n\nWhen you have multiple `.lua` files to compile and link, then just specify their `.o` files at the same time in the value of the `--with-ld-opt` option. For instance,\n\n```bash\n\n ./configure --with-ld-opt=\"/path/to/foo.o /path/to/bar.o\" ...\n```\n\nIf you have too many `.o` files, then it might not be feasible to name them all in a single command. In this case, you can build a static library (or archive) for your `.o` files, as in\n\n```bash\n\n ar rcus libmyluafiles.a *.o\n```\n\nthen you can link the `myluafiles` archive as a whole to your nginx executable:\n\n```bash\n\n ./configure \\\n --with-ld-opt=\"-L/path/to/lib -Wl,--whole-archive -lmyluafiles -Wl,--no-whole-archive\"\n```\n\nwhere `/path/to/lib` is the path of the directory containing the `libmyluafiles.a` file. It should be noted that the linker option `--whole-archive` is required here because otherwise our archive will be skipped because no symbols in our archive are mentioned in the main parts of the nginx executable.\n\n[Back to TOC](#table-of-contents)\n\nData Sharing within an Nginx Worker\n===================================\n\nTo globally share data among all the requests handled by the same Nginx worker\nprocess, encapsulate the shared data into a Lua module, use the Lua\n`require` builtin to import the module, and then manipulate the\nshared data in Lua. This works because required Lua modules are loaded only\nonce and all coroutines will share the same copy of the module (both its code\nand data).\n\nNote that the use of global Lua variables is *strongly discouraged*, as it may\nlead to unexpected race conditions between concurrent requests.\n\nHere is a small example on sharing data within an Nginx worker via a Lua module:\n\n```lua\n\n -- mydata.lua\n local _M = {}\n\n local data = {\n dog = 3,\n cat = 4,\n pig = 5,\n }\n\n function _M.get_age(name)\n return data[name]\n end\n\n return _M\n```\n\nand then accessing it from `nginx.conf`:\n\n```nginx\n\n location /lua {\n content_by_lua_block {\n local mydata = require \"mydata\"\n ngx.say(mydata.get_age(\"dog\"))\n }\n }\n```\n\nThe `mydata` module in this example will only be loaded and run on the first request to the location `/lua`,\nand all subsequent requests to the same Nginx worker process will use the reloaded instance of the\nmodule as well as the same copy of the data in it, until a `HUP` signal is sent to the Nginx master process to force a reload.\nThis data sharing technique is essential for high performance Lua applications based on this module.\n\nNote that this data sharing is on a *per-worker* basis and not on a *per-server* basis. That is, when there are multiple Nginx worker processes under an Nginx master, data sharing cannot cross the process boundary between these workers.\n\nIt is usually recommended to share read-only data this way. You can also share changeable data among all the concurrent requests of each Nginx worker process as\nlong as there is *no* nonblocking I/O operations (including [ngx.sleep](#ngxsleep))\nin the middle of your calculations. As long as you do not give the\ncontrol back to the Nginx event loop and ngx_lua's light thread\nscheduler (even implicitly), there can never be any race conditions in\nbetween. For this reason, always be very careful when you want to share changeable data on the\nworker level. Buggy optimizations can easily lead to hard-to-debug\nrace conditions under load.\n\nIf server-wide data sharing is required, then use one or more of the following approaches:\n\n1. Use the [ngx.shared.DICT](#ngxshareddict) API provided by this module.\n1. Use only a single Nginx worker and a single server (this is however not recommended when there is a multi core CPU or multiple CPUs in a single machine).\n1. Use data storage mechanisms such as `memcached`, `redis`, `MySQL` or `PostgreSQL`. [The OpenResty official releases](https://openresty.org) come with a set of companion Nginx modules and Lua libraries that provide interfaces with these data storage mechanisms.\n\n[Back to TOC](#table-of-contents)\n\nKnown Issues\n============\n\n[Back to TOC](#table-of-contents)\n\nTCP socket connect operation issues\n-----------------------------------\n\nThe [tcpsock:connect](#tcpsockconnect) method may indicate `success` despite connection failures such as with `Connection Refused` errors.\n\nHowever, later attempts to manipulate the cosocket object will fail and return the actual error status message generated by the failed connect operation.\n\nThis issue is due to limitations in the Nginx event model and only appears to affect Mac OS X.\n\n[Back to TOC](#table-of-contents)\n\nLua Coroutine Yielding/Resuming\n-------------------------------\n\n* Because Lua's `dofile` and `require` builtins are currently implemented as C functions in LuaJIT 2.0/2.1, if the Lua file being loaded by `dofile` or `require` invokes [ngx.location.capture*](#ngxlocationcapture), [ngx.exec](#ngxexec), [ngx.exit](#ngxexit), or other API functions requiring yielding in the *top-level* scope of the Lua file, then the Lua error \"attempt to yield across C-call boundary\" will be raised. To avoid this, put these calls requiring yielding into your own Lua functions in the Lua file instead of the top-level scope of the file.\n\n[Back to TOC](#table-of-contents)\n\nLua Variable Scope\n------------------\n\nCare must be taken when importing modules, and this form should be used:\n\n```lua\n\n local xxx = require('xxx')\n```\n\ninstead of the old deprecated form:\n\n```lua\n\n require('xxx')\n```\n\nHere is the reason: by design, the global environment has exactly the same lifetime as the Nginx request handler associated with it. Each request handler has its own set of Lua global variables and that is the idea of request isolation. The Lua module is actually loaded by the first Nginx request handler and is cached by the `require()` built-in in the `package.loaded` table for later reference, and the `module()` builtin used by some Lua modules has the side effect of setting a global variable to the loaded module table. But this global variable will be cleared at the end of the request handler, and every subsequent request handler all has its own (clean) global environment. So one will get Lua exception for accessing the `nil` value.\n\nThe use of Lua global variables is a generally inadvisable in the ngx_lua context as:\n\n1. the misuse of Lua globals has detrimental side effects on concurrent requests when such variables should instead be local in scope,\n1. Lua global variables require Lua table look-ups in the global environment which is computationally expensive, and\n1. some Lua global variable references may include typing errors which make such difficult to debug.\n\nIt is therefore *highly* recommended to always declare such within an appropriate local scope instead.\n\n```lua\n\n -- Avoid\n foo = 123\n -- Recommended\n local foo = 123\n\n -- Avoid\n function foo() return 123 end\n -- Recommended\n local function foo() return 123 end\n```\n\nTo find all instances of Lua global variables in your Lua code, run the [lua-releng tool](https://github.com/openresty/nginx-devel-utils/blob/master/lua-releng) across all `.lua` source files:\n\n $ lua-releng\n Checking use of Lua global variables in file lib/foo/bar.lua ...\n 1 [1489] SETGLOBAL 7 -1 ; contains\n 55 [1506] GETGLOBAL 7 -3 ; setvar\n 3 [1545] GETGLOBAL 3 -4 ; varexpand\n\nThe output says that the line 1489 of file `lib/foo/bar.lua` writes to a global variable named `contains`, the line 1506 reads from the global variable `setvar`, and line 1545 reads the global `varexpand`.\n\nThis tool will guarantee that local variables in the Lua module functions are all declared with the `local` keyword, otherwise a runtime exception will be thrown. It prevents undesirable race conditions while accessing such variables. See [Data Sharing within an Nginx Worker](#data-sharing-within-an-nginx-worker) for the reasons behind this.\n\n[Back to TOC](#table-of-contents)\n\nLocations Configured by Subrequest Directives of Other Modules\n--------------------------------------------------------------\n\nThe [ngx.location.capture](#ngxlocationcapture) and [ngx.location.capture_multi](#ngxlocationcapture_multi) directives cannot capture locations that include the [add_before_body](http://nginx.org/en/docs/http/ngx_http_addition_module.html#add_before_body), [add_after_body](http://nginx.org/en/docs/http/ngx_http_addition_module.html#add_after_body), [auth_request](https://nginx.org/en/docs/http/ngx_http_auth_request_module.html#auth_request), [echo_location](http://github.com/openresty/echo-nginx-module#echo_location), [echo_location_async](http://github.com/openresty/echo-nginx-module#echo_location_async), [echo_subrequest](http://github.com/openresty/echo-nginx-module#echo_subrequest), or [echo_subrequest_async](http://github.com/openresty/echo-nginx-module#echo_subrequest_async) directives.\n\n```nginx\n\n location /foo {\n content_by_lua_block {\n res = ngx.location.capture(\"/bar\")\n }\n }\n location /bar {\n echo_location /blah;\n }\n location /blah {\n echo \"Success!\";\n }\n```\n\n```nginx\n\n $ curl -i http://example.com/foo\n```\n\nwill not work as expected.\n\n[Back to TOC](#table-of-contents)\n\nCosockets Not Available Everywhere\n----------------------------------\n\nDue to internal limitations in the Nginx core, the cosocket API is disabled in the following contexts: [set_by_lua*](#set_by_lua), [log_by_lua*](#log_by_lua), [header_filter_by_lua*](#header_filter_by_lua), and [body_filter_by_lua](#body_filter_by_lua).\n\nThe cosockets are currently also disabled in the [init_by_lua*](#init_by_lua) and [init_worker_by_lua*](#init_worker_by_lua) directive contexts but we may add support for these contexts in the future because there is no limitation in the Nginx core (or the limitation might be worked around).\n\nThere exists a workaround, however, when the original context does *not* need to wait for the cosocket results. That is, creating a zero-delay timer via the [ngx.timer.at](#ngxtimerat) API and do the cosocket results in the timer handler, which runs asynchronously as to the original context creating the timer.\n\n[Back to TOC](#table-of-contents)\n\nSpecial Escaping Sequences\n--------------------------\n\n**NOTE** Following the `v0.9.17` release, this pitfall can be avoided by using the `*_by_lua_block {}` configuration directives.\n\nPCRE sequences such as `\\d`, `\\s`, or `\\w`, require special attention because in string literals, the backslash character, `\\`, is stripped out by both the Lua language parser and by the Nginx config file parser before processing if not within a `*_by_lua_block {}` directive. So the following snippet will not work as expected:\n\n```nginx\n\n # nginx.conf\n ? location /test {\n ? content_by_lua '\n ? local regex = \"\\d+\" -- THIS IS WRONG OUTSIDE OF A *_by_lua_block DIRECTIVE\n ? local m = ngx.re.match(\"hello, 1234\", regex)\n ? if m then ngx.say(m[0]) else ngx.say(\"not matched!\") end\n ? ';\n ? }\n # evaluates to \"not matched!\"\n```\n\nTo avoid this, *double* escape the backslash:\n\n```nginx\n\n # nginx.conf\n location /test {\n content_by_lua '\n local regex = \"\\\\\\\\d+\"\n local m = ngx.re.match(\"hello, 1234\", regex)\n if m then ngx.say(m[0]) else ngx.say(\"not matched!\") end\n ';\n }\n # evaluates to \"1234\"\n```\n\nHere, `\\\\\\\\d+` is stripped down to `\\\\d+` by the Nginx config file parser and this is further stripped down to `\\d+` by the Lua language parser before running.\n\nAlternatively, the regex pattern can be presented as a long-bracketed Lua string literal by encasing it in \"long brackets\", `[[...]]`, in which case backslashes have to only be escaped once for the Nginx config file parser.\n\n```nginx\n\n # nginx.conf\n location /test {\n content_by_lua '\n local regex = [[\\\\d+]]\n local m = ngx.re.match(\"hello, 1234\", regex)\n if m then ngx.say(m[0]) else ngx.say(\"not matched!\") end\n ';\n }\n # evaluates to \"1234\"\n```\n\nHere, `[[\\\\d+]]` is stripped down to `[[\\d+]]` by the Nginx config file parser and this is processed correctly.\n\nNote that a longer from of the long bracket, `[=[...]=]`, may be required if the regex pattern contains `[...]` sequences.\nThe `[=[...]=]` form may be used as the default form if desired.\n\n```nginx\n\n # nginx.conf\n location /test {\n content_by_lua '\n local regex = [=[[0-9]+]=]\n local m = ngx.re.match(\"hello, 1234\", regex)\n if m then ngx.say(m[0]) else ngx.say(\"not matched!\") end\n ';\n }\n # evaluates to \"1234\"\n```\n\nAn alternative approach to escaping PCRE sequences is to ensure that Lua code is placed in external script files and executed using the various `*_by_lua_file` directives.\nWith this approach, the backslashes are only stripped by the Lua language parser and therefore only need to be escaped once each.\n\n```lua\n\n -- test.lua\n local regex = \"\\\\d+\"\n local m = ngx.re.match(\"hello, 1234\", regex)\n if m then ngx.say(m[0]) else ngx.say(\"not matched!\") end\n -- evaluates to \"1234\"\n```\n\nWithin external script files, PCRE sequences presented as long-bracketed Lua string literals do not require modification.\n\n```lua\n\n -- test.lua\n local regex = [[\\d+]]\n local m = ngx.re.match(\"hello, 1234\", regex)\n if m then ngx.say(m[0]) else ngx.say(\"not matched!\") end\n -- evaluates to \"1234\"\n```\n\nAs noted earlier, PCRE sequences presented within `*_by_lua_block {}` directives (available following the `v0.9.17` release) do not require modification.\n\n```nginx\n\n # nginx.conf\n location /test {\n content_by_lua_block {\n local regex = [[\\d+]]\n local m = ngx.re.match(\"hello, 1234\", regex)\n if m then ngx.say(m[0]) else ngx.say(\"not matched!\") end\n }\n }\n # evaluates to \"1234\"\n```\n\n**NOTE** You are recommended to use `by_lua_file` when the Lua code is very long.\n\n[Back to TOC](#table-of-contents)\n\nMixing with SSI Not Supported\n-----------------------------\n\nMixing SSI with ngx_lua in the same Nginx request is not supported at all. Just use ngx_lua exclusively. Everything you can do with SSI can be done atop ngx_lua anyway and it can be more efficient when using ngx_lua.\n\n[Back to TOC](#table-of-contents)\n\nSPDY Mode Not Fully Supported\n-----------------------------\n\nCertain Lua APIs provided by ngx_lua do not work in Nginx's SPDY mode yet: [ngx.location.capture](#ngxlocationcapture), [ngx.location.capture_multi](#ngxlocationcapture_multi), and [ngx.req.socket](#ngxreqsocket).\n\n[Back to TOC](#table-of-contents)\n\nMissing data on short circuited requests\n----------------------------------------\n\nNginx may terminate a request early with (at least):\n\n* 400 (Bad Request)\n* 405 (Not Allowed)\n* 408 (Request Timeout)\n* 413 (Request Entity Too Large)\n* 414 (Request URI Too Large)\n* 494 (Request Headers Too Large)\n* 499 (Client Closed Request)\n* 500 (Internal Server Error)\n* 501 (Not Implemented)\n\nThis means that phases that normally run are skipped, such as the rewrite or\naccess phase. This also means that later phases that are run regardless, e.g.\n[log_by_lua](#log_by_lua), will not have access to information that is normally set in those\nphases.\n\n[Back to TOC](#table-of-contents)\n\nTODO\n====\n\n* cosocket: implement LuaSocket's unconnected UDP API.\n* cosocket: add support in the context of [init_by_lua*](#init_by_lua).\n* cosocket: review and merge aviramc's [patch](https://github.com/openresty/lua-nginx-module/pull/290) for adding the `bsdrecv` method.\n* cosocket: add configure options for different strategies of handling the cosocket connection exceeding in the pools.\n* use `ngx_hash_t` to optimize the built-in header look-up process for [ngx.req.set_header](#ngxreqset_header), and etc.\n* add `ignore_resp_headers`, `ignore_resp_body`, and `ignore_resp` options to [ngx.location.capture](#ngxlocationcapture) and [ngx.location.capture_multi](#ngxlocationcapture_multi) methods, to allow micro performance tuning on the user side.\n* add automatic Lua code time slicing support by yielding and resuming the Lua VM actively via Lua's debug hooks.\n* add `stat` mode similar to [mod_lua](https://httpd.apache.org/docs/trunk/mod/mod_lua.html).\n\n[Back to TOC](#table-of-contents)\n\nChanges\n=======\n\nThe changes made in every release of this module are listed in the change logs of the OpenResty bundle:\n\n\n\n[Back to TOC](#table-of-contents)\n\nBuild And Test\n==============\n\nThis module uses `.travis.yml` as the CI configuration.\nYou can always check `.travis.yml` for the latest CI configuration.\n\nFor developers, you need to run tests locally. You can use `util/run-ci.sh`\nto easily set up the environment and execute the test suite.\n\nTo run the Test from the beginning:\n\n```shell\ngit clone https://github.com/openresty/lua-nginx-module.git\ncd lua-nginx-module\nbash util/run-ci.sh\n```\n\nTest Suite\n==========\n\nThe following dependencies are required to run the test suite:\n\n* Nginx version >= 1.4.2\n\n* Perl modules:\n\t* Test::Nginx: \n\n* Nginx modules:\n\t* [ngx_devel_kit](https://github.com/simplresty/ngx_devel_kit)\n\t* [ngx_set_misc](https://github.com/openresty/set-misc-nginx-module)\n\t* [ngx_auth_request](http://mdounin.ru/files/ngx_http_auth_request_module-0.2.tar.gz) (this is not needed if you're using Nginx 1.5.4+.\n\t* [ngx_echo](https://github.com/openresty/echo-nginx-module)\n\t* [ngx_memc](https://github.com/openresty/memc-nginx-module)\n\t* [ngx_srcache](https://github.com/openresty/srcache-nginx-module)\n\t* ngx_lua (i.e., this module)\n\t* [ngx_lua_upstream](https://github.com/openresty/lua-upstream-nginx-module)\n\t* [ngx_headers_more](https://github.com/openresty/headers-more-nginx-module)\n\t* [ngx_drizzle](https://github.com/openresty/drizzle-nginx-module)\n\t* [ngx_rds_json](https://github.com/openresty/rds-json-nginx-module)\n\t* [ngx_coolkit](https://github.com/FRiCKLE/ngx_coolkit)\n\t* [ngx_redis2](https://github.com/openresty/redis2-nginx-module)\n\nThe order in which these modules are added during configuration is important because the position of any filter module in the\nfiltering chain determines the final output, for example. The correct adding order is shown above.\n\n* 3rd-party Lua libraries:\n\t* [lua-cjson](https://www.kyne.au/~mark/software/lua-cjson.php)\n\n* Applications:\n\t* mysql: create database 'ngx_test', grant all privileges to user 'ngx_test', password is 'ngx_test'\n\t* memcached: listening on the default port, 11211.\n\t* redis: listening on the default port, 6379.\n\nSee also the [developer build script](https://github.com/openresty/lua-nginx-module/blob/master/util/build.sh) for more details on setting up the testing environment.\n\nTo run the whole test suite in the default testing mode:\n\n cd /path/to/lua-nginx-module\n export PATH=/path/to/your/nginx/sbin:$PATH\n prove -I/path/to/test-nginx/lib -r t\n\nTo run specific test files:\n\n cd /path/to/lua-nginx-module\n export PATH=/path/to/your/nginx/sbin:$PATH\n prove -I/path/to/test-nginx/lib t/002-content.t t/003-errors.t\n\n\nTo run a specific test block in a particular test file, add the line `--- ONLY` to the test block you want to run, and then use the `prove` utility to run that `.t` file.\n\nThere are also various testing modes based on mockeagain, valgrind, and etc. Refer to the [Test::Nginx documentation](https://search.cpan.org/perldoc?Test::Nginx) for more details for various advanced testing modes. See also the test reports for the Nginx test cluster running on Amazon EC2: .\n\n[Back to TOC](#table-of-contents)\n\nCopyright and License\n=====================\n\nThis module is licensed under the BSD license.\n\nCopyright (C) 2009-2017, by Xiaozhe Wang (chaoslawful) .\n\nCopyright (C) 2009-2025, by Yichun \"agentzh\" Zhang (章亦春) , OpenResty Inc.\n\nAll rights reserved.\n\nRedistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:\n\n* Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.\n\n* Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.\n\nTHIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS \"AS IS\" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.\n\n[Back to TOC](#table-of-contents)\n\nSee Also\n========\n\nBlog posts:\n\n* [Introduction to Lua-Land CPU Flame Graphs](https://blog.openresty.com/en/lua-cpu-flame-graph/?src=gh_ngxlua)\n* [How OpenResty and Nginx Allocate and Manage Memory](https://blog.openresty.com/en//how-or-alloc-mem?src=gh_ngxlua)\n* [How OpenResty and Nginx Shared Memory Zones Consume RAM](https://blog.openresty.com/en/how-nginx-shm-consume-ram/?src=gh_ngxlua)\n* [Memory Fragmentation in OpenResty and Nginx's Shared Memory Zones](https://blog.openresty.com/en/nginx-shm-frag/?src=gh_ngxlua)\n\nOther related modules and libraries:\n\n* [ngx_stream_lua_module](https://github.com/openresty/stream-lua-nginx-module#readme) for an official port of this module for the Nginx \"stream\" subsystem (doing generic downstream TCP communications).\n* [lua-resty-memcached](https://github.com/openresty/lua-resty-memcached) library based on ngx_lua cosocket.\n* [lua-resty-redis](https://github.com/openresty/lua-resty-redis) library based on ngx_lua cosocket.\n* [lua-resty-mysql](https://github.com/openresty/lua-resty-mysql) library based on ngx_lua cosocket.\n* [lua-resty-upload](https://github.com/openresty/lua-resty-upload) library based on ngx_lua cosocket.\n* [lua-resty-dns](https://github.com/openresty/lua-resty-dns) library based on ngx_lua cosocket.\n* [lua-resty-websocket](https://github.com/openresty/lua-resty-websocket) library for both WebSocket server and client, based on ngx_lua cosocket.\n* [lua-resty-string](https://github.com/openresty/lua-resty-string) library based on [LuaJIT FFI](https://luajit.org/ext_ffi.html).\n* [lua-resty-lock](https://github.com/openresty/lua-resty-lock) library for a nonblocking simple lock API.\n* [lua-resty-cookie](https://github.com/cloudflare/lua-resty-cookie) library for HTTP cookie manipulation.\n* [Routing requests to different MySQL queries based on URI arguments](https://openresty.org/#RoutingMySQLQueriesBasedOnURIArgs)\n* [Dynamic Routing Based on Redis and Lua](https://openresty.org/#DynamicRoutingBasedOnRedis)\n* [Using LuaRocks with ngx_lua](https://openresty.org/#UsingLuaRocks)\n* [Introduction to ngx_lua](https://github.com/openresty/lua-nginx-module/wiki/Introduction)\n* [ngx_devel_kit](https://github.com/simplresty/ngx_devel_kit)\n* [echo-nginx-module](http://github.com/openresty/echo-nginx-module)\n* [drizzle-nginx-module](http://github.com/openresty/drizzle-nginx-module)\n* [postgres-nginx-module](https://github.com/FRiCKLE/ngx_postgres)\n* [memc-nginx-module](http://github.com/openresty/memc-nginx-module)\n* [The OpenResty bundle](https://openresty.org)\n* [Nginx Systemtap Toolkit](https://github.com/openresty/nginx-systemtap-toolkit)\n\n[Back to TOC](#table-of-contents)\n\nDirectives\n==========\n\n* [lua_load_resty_core](#lua_load_resty_core)\n* [lua_capture_error_log](#lua_capture_error_log)\n* [lua_use_default_type](#lua_use_default_type)\n* [lua_malloc_trim](#lua_malloc_trim)\n* [lua_code_cache](#lua_code_cache)\n* [lua_thread_cache_max_entries](#lua_thread_cache_max_entries)\n* [lua_regex_cache_max_entries](#lua_regex_cache_max_entries)\n* [lua_regex_match_limit](#lua_regex_match_limit)\n* [lua_package_path](#lua_package_path)\n* [lua_package_cpath](#lua_package_cpath)\n* [init_by_lua](#init_by_lua)\n* [init_by_lua_block](#init_by_lua_block)\n* [init_by_lua_file](#init_by_lua_file)\n* [init_worker_by_lua](#init_worker_by_lua)\n* [init_worker_by_lua_block](#init_worker_by_lua_block)\n* [init_worker_by_lua_file](#init_worker_by_lua_file)\n* [exit_worker_by_lua_block](#exit_worker_by_lua_block)\n* [exit_worker_by_lua_file](#exit_worker_by_lua_file)\n* [set_by_lua](#set_by_lua)\n* [set_by_lua_block](#set_by_lua_block)\n* [set_by_lua_file](#set_by_lua_file)\n* [precontent_by_lua_block](#precontent_by_lua_block)\n* [precontent_by_lua_file](#precontent_by_lua_file)\n* [content_by_lua](#content_by_lua)\n* [content_by_lua_block](#content_by_lua_block)\n* [content_by_lua_file](#content_by_lua_file)\n* [server_rewrite_by_lua_block](#server_rewrite_by_lua_block)\n* [server_rewrite_by_lua_file](#server_rewrite_by_lua_file)\n* [rewrite_by_lua](#rewrite_by_lua)\n* [rewrite_by_lua_block](#rewrite_by_lua_block)\n* [rewrite_by_lua_file](#rewrite_by_lua_file)\n* [access_by_lua](#access_by_lua)\n* [access_by_lua_block](#access_by_lua_block)\n* [access_by_lua_file](#access_by_lua_file)\n* [header_filter_by_lua](#header_filter_by_lua)\n* [header_filter_by_lua_block](#header_filter_by_lua_block)\n* [header_filter_by_lua_file](#header_filter_by_lua_file)\n* [body_filter_by_lua](#body_filter_by_lua)\n* [body_filter_by_lua_block](#body_filter_by_lua_block)\n* [body_filter_by_lua_file](#body_filter_by_lua_file)\n* [log_by_lua](#log_by_lua)\n* [log_by_lua_block](#log_by_lua_block)\n* [log_by_lua_file](#log_by_lua_file)\n* [balancer_by_lua_block](#balancer_by_lua_block)\n* [balancer_by_lua_file](#balancer_by_lua_file)\n* [balancer_keepalive](#balancer_keepalive)\n* [lua_need_request_body](#lua_need_request_body)\n* [ssl_client_hello_by_lua_block](#ssl_client_hello_by_lua_block)\n* [ssl_client_hello_by_lua_file](#ssl_client_hello_by_lua_file)\n* [ssl_certificate_by_lua_block](#ssl_certificate_by_lua_block)\n* [ssl_certificate_by_lua_file](#ssl_certificate_by_lua_file)\n* [ssl_session_fetch_by_lua_block](#ssl_session_fetch_by_lua_block)\n* [ssl_session_fetch_by_lua_file](#ssl_session_fetch_by_lua_file)\n* [ssl_session_store_by_lua_block](#ssl_session_store_by_lua_block)\n* [ssl_session_store_by_lua_file](#ssl_session_store_by_lua_file)\n* [proxy_ssl_certificate_by_lua_block](#proxy_ssl_certificate_by_lua_block)\n* [proxy_ssl_certificate_by_lua_file](#proxy_ssl_certificate_by_lua_file)\n* [proxy_ssl_verify_by_lua_block](#proxy_ssl_verify_by_lua_block)\n* [proxy_ssl_verify_by_lua_file](#proxy_ssl_verify_by_lua_file)\n* [lua_shared_dict](#lua_shared_dict)\n* [lua_socket_connect_timeout](#lua_socket_connect_timeout)\n* [lua_socket_send_timeout](#lua_socket_send_timeout)\n* [lua_socket_send_lowat](#lua_socket_send_lowat)\n* [lua_socket_read_timeout](#lua_socket_read_timeout)\n* [lua_socket_buffer_size](#lua_socket_buffer_size)\n* [lua_socket_pool_size](#lua_socket_pool_size)\n* [lua_socket_keepalive_timeout](#lua_socket_keepalive_timeout)\n* [lua_socket_log_errors](#lua_socket_log_errors)\n* [lua_ssl_ciphers](#lua_ssl_ciphers)\n* [lua_ssl_crl](#lua_ssl_crl)\n* [lua_ssl_protocols](#lua_ssl_protocols)\n* [lua_ssl_certificate](#lua_ssl_certificate)\n* [lua_ssl_certificate_key](#lua_ssl_certificate_key)\n* [lua_ssl_trusted_certificate](#lua_ssl_trusted_certificate)\n* [lua_ssl_verify_depth](#lua_ssl_verify_depth)\n* [lua_ssl_key_log](#lua_ssl_key_log)\n* [lua_ssl_conf_command](#lua_ssl_conf_command)\n* [lua_upstream_skip_openssl_default_verify](#lua_upstream_skip_openssl_default_verify)\n* [lua_http10_buffering](#lua_http10_buffering)\n* [rewrite_by_lua_no_postpone](#rewrite_by_lua_no_postpone)\n* [access_by_lua_no_postpone](#access_by_lua_no_postpone)\n* [precontent_by_lua_no_postpone](#precontent_by_lua_no_postpone)\n* [lua_transform_underscores_in_response_headers](#lua_transform_underscores_in_response_headers)\n* [lua_check_client_abort](#lua_check_client_abort)\n* [lua_max_pending_timers](#lua_max_pending_timers)\n* [lua_max_running_timers](#lua_max_running_timers)\n* [lua_sa_restart](#lua_sa_restart)\n* [lua_worker_thread_vm_pool_size](#lua_worker_thread_vm_pool_size)\n\n\nThe basic building blocks of scripting Nginx with Lua are directives. Directives are used to specify when the user Lua code is run and\nhow the result will be used. Below is a diagram showing the order in which directives are executed.\n\n![Lua Nginx Modules Directives](./doc/images/lua_nginx_modules_directives.drawio.png)\n\n[Back to TOC](#table-of-contents)\n\nlua_load_resty_core\n-------------------\n\n**syntax:** *lua_load_resty_core on|off*\n\n**default:** *lua_load_resty_core on*\n\n**context:** *http*\n\nThis directive is deprecated since the `v0.10.16` release of this\nmodule. The `resty.core` module from\n[lua-resty-core](https://github.com/openresty/lua-resty-core) is now mandatorily\nloaded during the Lua VM initialization. Specifying this directive will have no\neffect.\n\nThis directive was first introduced in the `v0.10.15` release and\nused to optionally load the `resty.core` module.\n\n[Back to TOC](#directives)\n\nlua_capture_error_log\n---------------------\n\n**syntax:** *lua_capture_error_log size*\n\n**default:** *none*\n\n**context:** *http*\n\nEnables a buffer of the specified `size` for capturing all the Nginx error log message data (not just those produced\nby this module or the Nginx http subsystem, but everything) without touching files or disks.\n\nYou can use units like `k` and `m` in the `size` value, as in\n\n```nginx\n\n lua_capture_error_log 100k;\n```\n\nAs a rule of thumb, a 4KB buffer can usually hold about 20 typical error log messages. So do the maths!\n\nThis buffer never grows. If it is full, new error log messages will replace the oldest ones in the buffer.\n\nThe size of the buffer must be bigger than the maximum length of a single error log message (which is 4K in OpenResty and 2K in stock NGINX).\n\nYou can read the messages in the buffer on the Lua land via the\n[get_logs()](https://github.com/openresty/lua-resty-core/blob/master/lib/ngx/errlog.md#get_logs)\nfunction of the\n[ngx.errlog](https://github.com/openresty/lua-resty-core/blob/master/lib/ngx/errlog.md#readme)\nmodule of the [lua-resty-core](https://github.com/openresty/lua-resty-core/blob/master/lib/ngx/errlog.md#readme)\nlibrary. This Lua API function will return the captured error log messages and\nalso remove these already read from the global capturing buffer, making room\nfor any new error log data. For this reason, the user should not configure this\nbuffer to be too big if the user read the buffered error log data fast enough.\n\nNote that the log level specified in the standard [error_log](https://nginx.org/r/error_log) directive\n*does* have effect on this capturing facility. It only captures log\nmessages of a level no lower than the specified log level in the [error_log](https://nginx.org/r/error_log) directive.\nThe user can still choose to set an even higher filtering log level on the fly via the Lua API function\n[errlog.set_filter_level](https://github.com/openresty/lua-resty-core/blob/master/lib/ngx/errlog.md#set_filter_level).\nSo it is more flexible than the static [error_log](https://nginx.org/r/error_log) directive.\n\nIt is worth noting that there is no way to capture the debugging logs\nwithout building OpenResty or Nginx with the `./configure`\noption `--with-debug`. And enabling debugging logs is\nstrongly discouraged in production builds due to high overhead.\n\nThis directive was first introduced in the `v0.10.9` release.\n\n[Back to TOC](#directives)\n\nlua_use_default_type\n--------------------\n\n**syntax:** *lua_use_default_type on | off*\n\n**default:** *lua_use_default_type on*\n\n**context:** *http, server, location, location if*\n\nSpecifies whether to use the MIME type specified by the [default_type](https://nginx.org/en/docs/http/ngx_http_core_module.html#default_type) directive for the default value of the `Content-Type` response header. Deactivate this directive if a default `Content-Type` response header for Lua request handlers is not desired.\n\nThis directive is turned on by default.\n\nThis directive was first introduced in the `v0.9.1` release.\n\n[Back to TOC](#directives)\n\nlua_malloc_trim\n---------------\n\n**syntax:** *lua_malloc_trim <request-count>*\n\n**default:** *lua_malloc_trim 1000*\n\n**context:** *http*\n\nAsks the underlying `libc` runtime library to release its cached free memory back to the operating system every\n`N` requests processed by the Nginx core. By default, `N` is 1000. You can configure the request count\nby using your own numbers. Smaller numbers mean more frequent releases, which may introduce higher CPU time consumption and\nsmaller memory footprint while larger numbers usually lead to less CPU time overhead and relatively larger memory footprint.\nJust tune the number for your own use cases.\n\nConfiguring the argument to `0` essentially turns off the periodical memory trimming altogether.\n\n```nginx\n\n lua_malloc_trim 0; # turn off trimming completely\n```\n\nThe current implementation uses an Nginx log phase handler to do the request counting. So the appearance of the\n[log_subrequest on](https://nginx.org/en/docs/http/ngx_http_core_module.html#log_subrequest) directives in `nginx.conf`\nmay make the counting faster when subrequests are involved. By default, only \"main requests\" count.\n\nNote that this directive does *not* affect the memory allocated by LuaJIT's own allocator based on the `mmap`\nsystem call.\n\nThis directive was first introduced in the `v0.10.7` release.\n\n[Back to TOC](#directives)\n\nlua_code_cache\n--------------\n**syntax:** *lua_code_cache on | off*\n\n**default:** *lua_code_cache on*\n\n**context:** *http, server, location, location if*\n\nEnables or disables the Lua code cache for Lua code in `*_by_lua_file` directives (like [set_by_lua_file](#set_by_lua_file) and\n[content_by_lua_file](#content_by_lua_file)) and Lua modules.\n\nWhen turning off, every request served by ngx_lua will run in a separate Lua VM instance, starting from the `0.9.3` release. So the Lua files referenced in [set_by_lua_file](#set_by_lua_file),\n[content_by_lua_file](#content_by_lua_file), [access_by_lua_file](#access_by_lua_file),\nand etc will not be cached\nand all Lua modules used will be loaded from scratch. With this in place, developers can adopt an edit-and-refresh approach.\n\nPlease note however, that Lua code written inlined within nginx.conf\nsuch as those specified by [set_by_lua](#set_by_lua), [content_by_lua](#content_by_lua),\n[access_by_lua](#access_by_lua), and [rewrite_by_lua](#rewrite_by_lua) will not be updated when you edit the inlined Lua code in your `nginx.conf` file because only the Nginx config file parser can correctly parse the `nginx.conf`\nfile and the only way is to reload the config file\nby sending a `HUP` signal or just to restart Nginx.\n\nEven when the code cache is enabled, Lua files which are loaded by `dofile` or `loadfile`\nin *_by_lua_file cannot be cached (unless you cache the results yourself). Usually you can either use the [init_by_lua](#init_by_lua)\nor [init_by_lua_file](#init-by_lua_file) directives to load all such files or just make these Lua files true Lua modules\nand load them via `require`.\n\nThe ngx_lua module does not support the `stat` mode available with the\nApache `mod_lua` module (yet).\n\nDisabling the Lua code cache is strongly\ndiscouraged for production use and should only be used during\ndevelopment as it has a significant negative impact on overall performance. For example, the performance of a \"hello world\" Lua example can drop by an order of magnitude after disabling the Lua code cache.\n\n[Back to TOC](#directives)\n\nlua_thread_cache_max_entries\n----------------------------\n\n**syntax:** *lua_thread_cache_max_entries <num>*\n\n**default:** *lua_thread_cache_max_entries 1024*\n\n**context:** *http*\n\nSpecifies the maximum number of entries allowed in the worker process level lua thread object cache.\n\nThis cache recycles the lua thread GC objects among all our \"light threads\".\n\nA zero value of `` disables the cache.\n\nNote that this feature requires OpenResty's LuaJIT with the new C API `lua_resetthread`.\n\nThis feature was first introduced in version `v0.10.9`.\n\n[Back to TOC](#directives)\n\nlua_regex_cache_max_entries\n---------------------------\n\n**syntax:** *lua_regex_cache_max_entries <num>*\n\n**default:** *lua_regex_cache_max_entries 1024*\n\n**context:** *http*\n\nSpecifies the maximum number of entries allowed in the worker process level compiled regex cache.\n\nThe regular expressions used in [ngx.re.match](#ngxrematch), [ngx.re.gmatch](#ngxregmatch), [ngx.re.sub](#ngxresub), and [ngx.re.gsub](#ngxregsub) will be cached within this cache if the regex option `o` (i.e., compile-once flag) is specified.\n\nThe default number of entries allowed is 1024 and when this limit is reached, new regular expressions will not be cached (as if the `o` option was not specified) and there will be one, and only one, warning in the `error.log` file:\n\n\n 2011/08/27 23:18:26 [warn] 31997#0: *1 lua exceeding regex cache max entries (1024), ...\n\n\nIf you are using the `ngx.re.*` implementation of [lua-resty-core](https://github.com/openresty/lua-resty-core) by loading the `resty.core.regex` module (or just the `resty.core` module), then an LRU cache is used for the regex cache being used here.\n\nDo not activate the `o` option for regular expressions (and/or `replace` string arguments for [ngx.re.sub](#ngxresub) and [ngx.re.gsub](#ngxregsub)) that are generated *on the fly* and give rise to infinite variations to avoid hitting the specified limit.\n\n[Back to TOC](#directives)\n\nlua_regex_match_limit\n---------------------\n\n**syntax:** *lua_regex_match_limit <num>*\n\n**default:** *lua_regex_match_limit 0*\n\n**context:** *http*\n\nSpecifies the \"match limit\" used by the PCRE library when executing the [ngx.re API](#ngxrematch). To quote the PCRE manpage, \"the limit ... has the effect of limiting the amount of backtracking that can take place.\"\n\nWhen the limit is hit, the error string \"pcre_exec() failed: -8\" will be returned by the [ngx.re API](#ngxrematch) functions on the Lua land.\n\nWhen setting the limit to 0, the default \"match limit\" when compiling the PCRE library is used. And this is the default value of this directive.\n\nThis directive was first introduced in the `v0.8.5` release.\n\n[Back to TOC](#directives)\n\nlua_package_path\n----------------\n\n**syntax:** *lua_package_path <lua-style-path-str>*\n\n**default:** *The content of LUA_PATH environment variable or Lua's compiled-in defaults.*\n\n**context:** *http*\n\nSets the Lua module search path used by scripts specified by [set_by_lua](#set_by_lua),\n[content_by_lua](#content_by_lua) and others. The path string is in standard Lua path form, and `;;`\ncan be used to stand for the original search paths.\n\nAs from the `v0.5.0rc29` release, the special notation `$prefix` or `${prefix}` can be used in the search path string to indicate the path of the `server prefix` usually determined by the `-p PATH` command-line option while starting the Nginx server.\n\n[Back to TOC](#directives)\n\nlua_package_cpath\n-----------------\n\n**syntax:** *lua_package_cpath <lua-style-cpath-str>*\n\n**default:** *The content of LUA_CPATH environment variable or Lua's compiled-in defaults.*\n\n**context:** *http*\n\nSets the Lua C-module search path used by scripts specified by [set_by_lua](#set_by_lua),\n[content_by_lua](#content_by_lua) and others. The cpath string is in standard Lua cpath form, and `;;`\ncan be used to stand for the original cpath.\n\nAs from the `v0.5.0rc29` release, the special notation `$prefix` or `${prefix}` can be used in the search path string to indicate the path of the `server prefix` usually determined by the `-p PATH` command-line option while starting the Nginx server.\n\n[Back to TOC](#directives)\n\ninit_by_lua\n-----------\n\n**syntax:** *init_by_lua <lua-script-str>*\n\n**context:** *http*\n\n**phase:** *loading-config*\n\n**NOTE** Use of this directive is *discouraged* following the `v0.9.17` release. Use the [init_by_lua_block](#init_by_lua_block) directive instead.\n\nSimilar to the [init_by_lua_block](#init_by_lua_block) directive, but accepts the Lua source directly in an Nginx string literal (which requires\nspecial character escaping).\n\nFor instance,\n\n```nginx\n\n init_by_lua '\n print(\"I need no extra escaping here, for example: \\r\\nblah\")\n '\n```\n\nThis directive was first introduced in the `v0.5.5` release.\n\n[Back to TOC](#directives)\n\ninit_by_lua_block\n-----------------\n\n**syntax:** *init_by_lua_block { lua-script }*\n\n**context:** *http*\n\n**phase:** *loading-config*\n\n\nWhen Nginx receives the `HUP` signal and starts reloading the config file, the Lua VM will also be re-created and `init_by_lua_block` will run again on the new Lua VM. In case that the [lua_code_cache](#lua_code_cache) directive is turned off (default on), the `init_by_lua_block` handler will run upon every request because in this special mode a standalone Lua VM is always created for each request.\n\nUsually you can pre-load Lua modules at server start-up by means of this hook and take advantage of modern operating systems' copy-on-write (COW) optimization. Here is an example for pre-loading Lua modules:\n\n```nginx\n\n # this runs before forking out nginx worker processes:\n init_by_lua_block { require \"cjson\" }\n\n server {\n location = /api {\n content_by_lua_block {\n -- the following require() will just return\n -- the already loaded module from package.loaded:\n ngx.say(require \"cjson\".encode{dog = 5, cat = 6})\n }\n }\n }\n```\n\nYou can also initialize the [lua_shared_dict](#lua_shared_dict) shm storage at this phase. Here is an example for this:\n\n```nginx\n\n lua_shared_dict dogs 1m;\n\n init_by_lua_block {\n local dogs = ngx.shared.dogs\n dogs:set(\"Tom\", 56)\n }\n\n server {\n location = /api {\n content_by_lua_block {\n local dogs = ngx.shared.dogs\n ngx.say(dogs:get(\"Tom\"))\n }\n }\n }\n```\n\nBut note that, the [lua_shared_dict](#lua_shared_dict)'s shm storage will not be cleared through a config reload (via the `HUP` signal, for example). So if you do *not* want to re-initialize the shm storage in your `init_by_lua_block` code in this case, then you just need to set a custom flag in the shm storage and always check the flag in your `init_by_lua_block` code.\n\nBecause the Lua code in this context runs before Nginx forks its worker processes (if any), data or code loaded here will enjoy the [Copy-on-write (COW)](https://en.wikipedia.org/wiki/Copy-on-write) feature provided by many operating systems among all the worker processes, thus saving a lot of memory.\n\nDo *not* initialize your own Lua global variables in this context because use of Lua global variables have performance penalties and can lead to global namespace pollution (see the [Lua Variable Scope](#lua-variable-scope) section for more details). The recommended way is to use proper [Lua module](https://www.lua.org/manual/5.1/manual.html#5.3) files (but do not use the standard Lua function [module()](https://www.lua.org/manual/5.1/manual.html#pdf-module) to define Lua modules because it pollutes the global namespace as well) and call [require()](https://www.lua.org/manual/5.1/manual.html#pdf-require) to load your own module files in `init_by_lua_block` or other contexts ([require()](https://www.lua.org/manual/5.1/manual.html#pdf-require) does cache the loaded Lua modules in the global `package.loaded` table in the Lua registry so your modules will only loaded once for the whole Lua VM instance).\n\nOnly a small set of the [Nginx API for Lua](#nginx-api-for-lua) is supported in this context:\n\n* Logging APIs: [ngx.log](#ngxlog) and [print](#print),\n* Shared Dictionary API: [ngx.shared.DICT](#ngxshareddict).\n\nMore Nginx APIs for Lua may be supported in this context upon future user requests.\n\nBasically you can safely use Lua libraries that do blocking I/O in this very context because blocking the master process during server start-up is completely okay. Even the Nginx core does blocking I/O (at least on resolving upstream's host names) at the configure-loading phase.\n\nYou should be very careful about potential security vulnerabilities in your Lua code registered in this context because the Nginx master process is often run under the `root` account.\n\nThis directive was first introduced in the `v0.9.17` release.\n\nSee also the following blog posts for more details on OpenResty and Nginx's shared memory zones:\n\n* [How OpenResty and Nginx Shared Memory Zones Consume RAM](https://blog.openresty.com/en/how-nginx-shm-consume-ram/?src=gh_ngxlua)\n* [Memory Fragmentation in OpenResty and Nginx's Shared Memory Zones](https://blog.openresty.com/en/nginx-shm-frag/?src=gh_ngxlua)\n\n[Back to TOC](#directives)\n\ninit_by_lua_file\n----------------\n\n**syntax:** *init_by_lua_file <path-to-lua-script-file>*\n\n**context:** *http*\n\n**phase:** *loading-config*\n\nEquivalent to [init_by_lua_block](#init_by_lua_block), except that the file specified by `` contains the Lua code or [LuaJIT bytecode](#luajit-bytecode-support) to be executed.\n\nWhen a relative path like `foo/bar.lua` is given, they will be turned into the absolute path relative to the `server prefix` path determined by the `-p PATH` command-line option while starting the Nginx server.\n\nThis directive was first introduced in the `v0.5.5` release.\n\n[Back to TOC](#directives)\n\ninit_worker_by_lua\n------------------\n\n**syntax:** *init_worker_by_lua <lua-script-str>*\n\n**context:** *http*\n\n**phase:** *starting-worker*\n\n**NOTE** Use of this directive is *discouraged* following the `v0.9.17` release. Use the [init_worker_by_lua_block](#init_worker_by_lua_block) directive instead.\n\nSimilar to the [init_worker_by_lua_block](#init_worker_by_lua_block) directive, but accepts the Lua source directly in an Nginx string literal (which requires\nspecial character escaping).\n\nFor instance,\n\n```nginx\n\n init_worker_by_lua '\n print(\"I need no extra escaping here, for example: \\r\\nblah\")\n ';\n```\n\nThis directive was first introduced in the `v0.9.5` release.\n\nThis hook no longer runs in the cache manager and cache loader processes since the `v0.10.12` release.\n\n[Back to TOC](#directives)\n\ninit_worker_by_lua_block\n------------------------\n\n**syntax:** *init_worker_by_lua_block { lua-script }*\n\n**context:** *http*\n\n**phase:** *starting-worker*\n\nRuns the specified Lua code upon every Nginx worker process's startup when the master process is enabled. When the master process is disabled, this hook will just run after [init_by_lua*](#init_by_lua_block).\n\nThis hook is often used to create per-worker reoccurring timers (via the [ngx.timer.at](#ngxtimerat) Lua API), either for backend health-check or other timed routine work. Below is an example,\n\n```nginx\n\n init_worker_by_lua_block {\n local delay = 3 -- in seconds\n local new_timer = ngx.timer.at\n local log = ngx.log\n local ERR = ngx.ERR\n local check\n\n check = function(premature)\n if not premature then\n -- do the health check or other routine work\n local ok, err = new_timer(delay, check)\n if not ok then\n log(ERR, \"failed to create timer: \", err)\n return\n end\n end\n\n -- do something in timer\n end\n\n local hdl, err = new_timer(delay, check)\n if not hdl then\n log(ERR, \"failed to create timer: \", err)\n return\n end\n\n -- other job in init_worker_by_lua\n }\n```\n\nThis directive was first introduced in the `v0.9.17` release.\n\nThis hook no longer runs in the cache manager and cache loader processes since the `v0.10.12` release.\n\n[Back to TOC](#directives)\n\ninit_worker_by_lua_file\n-----------------------\n\n**syntax:** *init_worker_by_lua_file <lua-file-path>*\n\n**context:** *http*\n\n**phase:** *starting-worker*\n\nSimilar to [init_worker_by_lua_block](#init_worker_by_lua_block), but accepts the file path to a Lua source file or Lua bytecode file.\n\nThis directive was first introduced in the `v0.9.5` release.\n\nThis hook no longer runs in the cache manager and cache loader processes since the `v0.10.12` release.\n\n[Back to TOC](#directives)\n\nexit_worker_by_lua_block\n------------------------\n\n**syntax:** *exit_worker_by_lua_block { lua-script }*\n\n**context:** *http*\n\n**phase:** *exiting-worker*\n\nRuns the specified Lua code upon every Nginx worker process's exit when the master process is enabled. When the master process is disabled, this hook will run before the Nginx process exits.\n\nThis hook is often used to release resources allocated by each worker (e.g. resources allocated by [init_worker_by_lua*](#init_worker_by_lua_block)), or to prevent workers from exiting abnormally.\n\nFor example,\n\n```nginx\n\n exit_worker_by_lua_block {\n print(\"log from exit_worker_by_lua_block\")\n }\n```\n\nIt's not allowed to create a timer (even a 0-delay timer) here since it runs after all timers have been processed.\n\nThis directive was first introduced in the `v0.10.18` release.\n\n[Back to TOC](#directives)\n\nexit_worker_by_lua_file\n-----------------------\n\n**syntax:** *exit_worker_by_lua_file <path-to-lua-script-file>*\n\n**context:** *http*\n\n**phase:** *exiting-worker*\n\nSimilar to [exit_worker_by_lua_block](#exit_worker_by_lua_block), but accepts the file path to a Lua source file or Lua bytecode file.\n\nThis directive was first introduced in the `v0.10.18` release.\n\n[Back to TOC](#directives)\n\nset_by_lua\n----------\n\n**syntax:** *set_by_lua $res <lua-script-str> [$arg1 $arg2 ...]*\n\n**context:** *server, server if, location, location if*\n\n**phase:** *rewrite*\n\n**NOTE** Use of this directive is *discouraged* following the `v0.9.17` release. Use the [set_by_lua_block](#set_by_lua_block) directive instead.\n\nSimilar to the [set_by_lua_block](#set_by_lua_block) directive, but accepts the Lua source directly in an Nginx string literal (which requires\nspecial character escaping), and\n1. this directive support extra arguments after the Lua script.\n\nFor example,\n\n```nginx\n\n set_by_lua $res ' return 32 + math.cos(32) ';\n # $res now has the value \"32.834223360507\" or alike.\n```\n\nAs from the `v0.5.0rc29` release, Nginx variable interpolation is disabled in the `` argument of this directive and therefore, the dollar sign character (`$`) can be used directly.\n\nThis directive requires the [ngx_devel_kit](https://github.com/simplresty/ngx_devel_kit) module.\n\n[Back to TOC](#directives)\n\nset_by_lua_block\n----------------\n\n**syntax:** *set_by_lua_block $res { lua-script }*\n\n**context:** *server, server if, location, location if*\n\n**phase:** *rewrite*\n\nExecutes code specified inside a pair of curly braces (`{}`), and returns string output to `$res`.\nThe code inside a pair of curly braces (`{}`) can make [API calls](#nginx-api-for-lua) and can retrieve input arguments from the `ngx.arg` table (index starts from `1` and increases sequentially).\n\nThis directive is designed to execute short, fast running code blocks as the Nginx event loop is blocked during code execution. Time consuming code sequences should therefore be avoided.\n\nThis directive is implemented by injecting custom commands into the standard [ngx_http_rewrite_module](http://nginx.org/en/docs/http/ngx_http_rewrite_module.html)'s command list. Because [ngx_http_rewrite_module](http://nginx.org/en/docs/http/ngx_http_rewrite_module.html) does not support nonblocking I/O in its commands, Lua APIs requiring yielding the current Lua \"light thread\" cannot work in this directive.\n\nAt least the following API functions are currently disabled within the context of `set_by_lua_block`:\n\n* Output API functions (e.g., [ngx.say](#ngxsay) and [ngx.send_headers](#ngxsend_headers))\n* Control API functions (e.g., [ngx.exit](#ngxexit))\n* Subrequest API functions (e.g., [ngx.location.capture](#ngxlocationcapture) and [ngx.location.capture_multi](#ngxlocationcapture_multi))\n* Cosocket API functions (e.g., [ngx.socket.tcp](#ngxsockettcp) and [ngx.req.socket](#ngxreqsocket)).\n* Sleeping API function [ngx.sleep](#ngxsleep).\n\nIn addition, note that this directive can only write out a value to a single Nginx variable at\na time. However, a workaround is possible using the [ngx.var.VARIABLE](#ngxvarvariable) interface.\n\n```nginx\n\n location /foo {\n set $diff ''; # we have to predefine the $diff variable here\n\n set_by_lua_block $sum {\n local a = 32\n local b = 56\n\n ngx.var.diff = a - b -- write to $diff directly\n return a + b -- return the $sum value normally\n }\n\n echo \"sum = $sum, diff = $diff\";\n }\n```\n\nThis directive can be freely mixed with all directives of the [ngx_http_rewrite_module](http://nginx.org/en/docs/http/ngx_http_rewrite_module.html), [set-misc-nginx-module](http://github.com/openresty/set-misc-nginx-module), and [array-var-nginx-module](http://github.com/openresty/array-var-nginx-module) modules. All of these directives will run in the same order as they appear in the config file.\n\n```nginx\n\n set $foo 32;\n set_by_lua_block $bar { return tonumber(ngx.var.foo) + 1 }\n set $baz \"bar: $bar\"; # $baz == \"bar: 33\"\n```\n\nNo special escaping is required in the Lua code block.\n\nThis directive requires the [ngx_devel_kit](https://github.com/simplresty/ngx_devel_kit) module.\n\nThis directive was first introduced in the `v0.9.17` release.\n\n[Back to TOC](#directives)\n\nset_by_lua_file\n---------------\n\n**syntax:** *set_by_lua_file $res <path-to-lua-script-file> [$arg1 $arg2 ...]*\n\n**context:** *server, server if, location, location if*\n\n**phase:** *rewrite*\n\nEquivalent to [set_by_lua_block](#set_by_lua_block), except that the file specified by `` contains the Lua code, or, as from the `v0.5.0rc32` release, the [LuaJIT bytecode](#luajit-bytecode-support) to be executed.\n\nNginx variable interpolation is supported in the `` argument string of this directive. But special care must be taken for injection attacks.\n\nWhen a relative path like `foo/bar.lua` is given, they will be turned into the absolute path relative to the `server prefix` path determined by the `-p PATH` command-line option while starting the Nginx server.\n\nWhen the Lua code cache is turned on (by default), the user code is loaded once at the first request and cached\nand the Nginx config must be reloaded each time the Lua source file is modified.\nThe Lua code cache can be temporarily disabled during development by\nswitching [lua_code_cache](#lua_code_cache) `off` in `nginx.conf` to avoid reloading Nginx.\n\nThis directive requires the [ngx_devel_kit](https://github.com/simplresty/ngx_devel_kit) module.\n\n[Back to TOC](#directives)\n\nprecontent_by_lua_block\n--------------------\n\n**syntax:** *precontent_by_lua_block { lua-script }*\n\n**context:** *http, server, location, location if*\n\n**phase:** *precontent tail*\n\nActs as a precontent phase handler and executes Lua code string specified in `{ ` contains the Lua code, or, as from the `v0.5.0rc32` release, the [LuaJIT bytecode](#luajit-bytecode-support) to be executed.\n\nNginx variables can be used in the `` string to provide flexibility. This however carries some risks and is not ordinarily recommended.\n\nWhen a relative path like `foo/bar.lua` is given, they will be turned into the absolute path relative to the `server prefix` path determined by the `-p PATH` command-line option while starting the Nginx server.\n\nWhen the Lua code cache is turned on (by default), the user code is loaded once at the first request and cached\nand the Nginx config must be reloaded each time the Lua source file is modified.\nThe Lua code cache can be temporarily disabled during development by switching [lua_code_cache](#lua_code_cache) `off` in `nginx.conf` to avoid repeatedly reloading Nginx.\n\nNginx variables are supported in the file path for dynamic dispatch just as in [content_by_lua_file](#content_by_lua_file).\n\nBut be very careful about malicious user inputs and always carefully validate or filter out the user-supplied path components.\n\n[Back to TOC](#directives)\n\ncontent_by_lua\n--------------\n\n**syntax:** *content_by_lua <lua-script-str>*\n\n**context:** *location, location if*\n\n**phase:** *content*\n\n**NOTE** Use of this directive is *discouraged* following the `v0.9.17` release. Use the [content_by_lua_block](#content_by_lua_block) directive instead.\n\nSimilar to the [content_by_lua_block](#content_by_lua_block) directive, but accepts the Lua source directly in an Nginx string literal (which requires\nspecial character escaping).\n\nFor instance,\n\n```nginx\n\n content_by_lua '\n ngx.say(\"I need no extra escaping here, for example: \\r\\nblah\")\n ';\n```\n\n[Back to TOC](#directives)\n\ncontent_by_lua_block\n--------------------\n\n**syntax:** *content_by_lua_block { lua-script }*\n\n**context:** *location, location if*\n\n**phase:** *content*\n\nFor instance,\n\n```nginx\n\n content_by_lua_block {\n ngx.say(\"I need no extra escaping here, for example: \\r\\nblah\")\n }\n```\n\nActs as a \"content handler\" and executes Lua code string specified in `{ lua-script }` for every request.\nThe Lua code may make [API calls](#nginx-api-for-lua) and is executed as a new spawned coroutine in an independent global environment (i.e. a sandbox).\n\nDo not use this directive and other content handler directives in the same location. For example, this directive and the [proxy_pass](http://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_pass) directive should not be used in the same location.\n\nThis directive was first introduced in the `v0.9.17` release.\n\n[Back to TOC](#directives)\n\ncontent_by_lua_file\n-------------------\n\n**syntax:** *content_by_lua_file <path-to-lua-script-file>*\n\n**context:** *location, location if*\n\n**phase:** *content*\n\nEquivalent to [content_by_lua_block](#content_by_lua_block), except that the file specified by `` contains the Lua code, or, as from the `v0.5.0rc32` release, the [LuaJIT bytecode](#luajit-bytecode-support) to be executed.\n\nIf the file is not found, a `404 Not Found` status code will be returned, and a `503 Service Temporarily Unavailable` status code will be returned in case of errors in reading other files.\n\nNginx variables can be used in the `` string to provide flexibility. This however carries some risks and is not ordinarily recommended.\n\nWhen a relative path like `foo/bar.lua` is given, they will be turned into the absolute path relative to the `server prefix` path determined by the `-p PATH` command-line option while starting the Nginx server.\n\nWhen the Lua code cache is turned on (by default), the user code is loaded once at the first request and cached\nand the Nginx config must be reloaded each time the Lua source file is modified.\nThe Lua code cache can be temporarily disabled during development by\nswitching [lua_code_cache](#lua_code_cache) `off` in `nginx.conf` to avoid reloading Nginx.\n\nNginx variables are supported in the file path for dynamic dispatch, for example:\n\n```nginx\n\n # CAUTION: contents in nginx var must be carefully filtered,\n # otherwise there'll be great security risk!\n location ~ ^/app/([-_a-zA-Z0-9/]+) {\n set $path $1;\n content_by_lua_file /path/to/lua/app/root/$path.lua;\n }\n```\n\nBut be very careful about malicious user inputs and always carefully validate or filter out the user-supplied path components.\n\n[Back to TOC](#directives)\n\nserver_rewrite_by_lua_block\n---------------------------\n\n**syntax:** *server_rewrite_by_lua_block { lua-script }*\n\n**context:** *http, server*\n\n**phase:** *server rewrite*\n\nActs as a server rewrite phase handler and executes Lua code string specified in `{ lua-script }` for every request.\nThe Lua code may make [API calls](#nginx-api-for-lua) and is executed as a new spawned coroutine in an independent global environment (i.e. a sandbox).\n\n```nginx\n\n server {\n ...\n\n server_rewrite_by_lua_block {\n ngx.ctx.a = \"server_rewrite_by_lua_block in http\"\n }\n\n location /lua {\n content_by_lua_block {\n ngx.say(ngx.ctx.a)\n ngx.log(ngx.INFO, ngx.ctx.a)\n \t}\n }\n }\n```\n\nJust as any other rewrite phase handlers, [server_rewrite_by_lua_block](#server_rewrite_by_lua_block) also runs in subrequests.\n\n```nginx\n\n server {\n server_rewrite_by_lua_block {\n ngx.log(ngx.INFO, \"is_subrequest:\", ngx.is_subrequest)\n }\n\n location /lua {\n content_by_lua_block {\n local res = ngx.location.capture(\"/sub\")\n ngx.print(res.body)\n }\n }\n\n location /sub {\n content_by_lua_block {\n ngx.say(\"OK\")\n }\n }\n }\n```\n\nNote that when calling `ngx.exit(ngx.OK)` within a [server_rewrite_by_lua_block](#server_rewrite_by_lua_block) handler, the Nginx request processing control flow will still continue to the content handler. To terminate the current request from within a [server_rewrite_by_lua_block](#server_rewrite_by_lua_block) handler, call [ngx.exit](#ngxexit) with status >= 200 (`ngx.HTTP_OK`) and status < 300 (`ngx.HTTP_SPECIAL_RESPONSE`) for successful quits and `ngx.exit(ngx.HTTP_INTERNAL_SERVER_ERROR)` (or its friends) for failures.\n\n\n```nginx\n\n server_rewrite_by_lua_block {\n ngx.exit(503)\n }\n\n location /bar {\n ...\n # never exec\n }\n```\n\n\n[Back to TOC](#directives)\n\nserver_rewrite_by_lua_file\n--------------------------\n\n**syntax:** *server_rewrite_by_lua_file <path-to-lua-script-file>*\n\n**context:** *http, server*\n\n**phase:** *server rewrite*\n\nEquivalent to [server_rewrite_by_lua_block](#server_rewrite_by_lua_block), except that the file specified by `` contains the Lua code, or, as from the `v0.10.22` release, the [LuaJIT bytecode](#luajit-bytecode-support) to be executed.\n\nNginx variables can be used in the `` string to provide flexibility. This however carries some risks and is not ordinarily recommended.\n\nWhen a relative path like `foo/bar.lua` is given, they will be turned into the absolute path relative to the `server prefix` path determined by the `-p PATH` command-line option while starting the Nginx server.\n\nWhen the Lua code cache is turned on (by default), the user code is loaded once at the first request and cached and the Nginx config must be reloaded each time the Lua source file is modified. The Lua code cache can be temporarily disabled during development by switching [lua_code_cache](#lua_code_cache) `off` in `nginx.conf` to avoid reloading Nginx.\n\n[Back to TOC](#directives)\n\nrewrite_by_lua\n--------------\n\n**syntax:** *rewrite_by_lua <lua-script-str>*\n\n**context:** *http, server, location, location if*\n\n**phase:** *rewrite tail*\n\n**NOTE** Use of this directive is *discouraged* following the `v0.9.17` release. Use the [rewrite_by_lua_block](#rewrite_by_lua_block) directive instead.\n\nSimilar to the [rewrite_by_lua_block](#rewrite_by_lua_block) directive, but accepts the Lua source directly in an Nginx string literal (which requires\nspecial character escaping).\n\nFor instance,\n\n```nginx\n\n rewrite_by_lua '\n do_something(\"hello, world!\\nhiya\\n\")\n ';\n```\n\n[Back to TOC](#directives)\n\nrewrite_by_lua_block\n--------------------\n\n**syntax:** *rewrite_by_lua_block { lua-script }*\n\n**context:** *http, server, location, location if*\n\n**phase:** *rewrite tail*\n\nActs as a rewrite phase handler and executes Lua code string specified in `{ lua-script }` for every request.\nThe Lua code may make [API calls](#nginx-api-for-lua) and is executed as a new spawned coroutine in an independent global environment (i.e. a sandbox).\n\nNote that this handler always runs *after* the standard [ngx_http_rewrite_module](http://nginx.org/en/docs/http/ngx_http_rewrite_module.html). So the following will work as expected:\n\n```nginx\n\n location /foo {\n set $a 12; # create and initialize $a\n set $b \"\"; # create and initialize $b\n rewrite_by_lua_block {\n ngx.var.b = tonumber(ngx.var.a) + 1\n }\n echo \"res = $b\";\n }\n```\n\nbecause `set $a 12` and `set $b \"\"` run *before* [rewrite_by_lua_block](#rewrite_by_lua_block).\n\nOn the other hand, the following will not work as expected:\n\n```nginx\n\n ? location /foo {\n ? set $a 12; # create and initialize $a\n ? set $b ''; # create and initialize $b\n ? rewrite_by_lua_block {\n ? ngx.var.b = tonumber(ngx.var.a) + 1\n ? }\n ? if ($b = '13') {\n ? rewrite ^ /bar redirect;\n ? break;\n ? }\n ?\n ? echo \"res = $b\";\n ? }\n```\n\nbecause `if` runs *before* [rewrite_by_lua_block](#rewrite_by_lua_block) even if it is placed after [rewrite_by_lua_block](#rewrite_by_lua_block) in the config.\n\nThe right way of doing this is as follows:\n\n```nginx\n\n location /foo {\n set $a 12; # create and initialize $a\n set $b ''; # create and initialize $b\n rewrite_by_lua_block {\n ngx.var.b = tonumber(ngx.var.a) + 1\n if tonumber(ngx.var.b) == 13 then\n return ngx.redirect(\"/bar\")\n end\n }\n\n echo \"res = $b\";\n }\n```\n\nNote that the [ngx_eval](http://www.grid.net.ru/nginx/eval.en.html) module can be approximated by using [rewrite_by_lua_block](#rewrite_by_lua_block). For example,\n\n```nginx\n\n location / {\n eval $res {\n proxy_pass http://foo.com/check-spam;\n }\n\n if ($res = 'spam') {\n rewrite ^ /terms-of-use.html redirect;\n }\n\n fastcgi_pass ...;\n }\n```\n\ncan be implemented in ngx_lua as:\n\n```nginx\n\n location = /check-spam {\n internal;\n proxy_pass http://foo.com/check-spam;\n }\n\n location / {\n rewrite_by_lua_block {\n local res = ngx.location.capture(\"/check-spam\")\n if res.body == \"spam\" then\n return ngx.redirect(\"/terms-of-use.html\")\n end\n }\n\n fastcgi_pass ...;\n }\n```\n\nJust as any other rewrite phase handlers, [rewrite_by_lua_block](#rewrite_by_lua_block) also runs in subrequests.\n\nNote that when calling `ngx.exit(ngx.OK)` within a [rewrite_by_lua_block](#rewrite_by_lua_block) handler, the Nginx request processing control flow will still continue to the content handler. To terminate the current request from within a [rewrite_by_lua_block](#rewrite_by_lua_block) handler, call [ngx.exit](#ngxexit) with status >= 200 (`ngx.HTTP_OK`) and status < 300 (`ngx.HTTP_SPECIAL_RESPONSE`) for successful quits and `ngx.exit(ngx.HTTP_INTERNAL_SERVER_ERROR)` (or its friends) for failures.\n\nIf the [ngx_http_rewrite_module](http://nginx.org/en/docs/http/ngx_http_rewrite_module.html)'s [rewrite](http://nginx.org/en/docs/http/ngx_http_rewrite_module.html#rewrite) directive is used to change the URI and initiate location re-lookups (internal redirections), then any [rewrite_by_lua_block](#rewrite_by_lua_block) or [rewrite_by_lua_file_block](#rewrite_by_lua_file_block) code sequences within the current location will not be executed. For example,\n\n```nginx\n\n location /foo {\n rewrite ^ /bar;\n rewrite_by_lua_block {\n ngx.exit(503)\n }\n }\n location /bar {\n ...\n }\n```\n\nHere the Lua code `ngx.exit(503)` will never run. This will be the case if `rewrite ^ /bar last` is used as this will similarly initiate an internal redirection. If the `break` modifier is used instead, there will be no internal redirection and the `rewrite_by_lua_block` code will be executed.\n\nThe `rewrite_by_lua_block` code will always run at the end of the `rewrite` request-processing phase unless [rewrite_by_lua_no_postpone](#rewrite_by_lua_no_postpone) is turned on.\n\nThis directive was first introduced in the `v0.9.17` release.\n\n[Back to TOC](#directives)\n\nrewrite_by_lua_file\n-------------------\n\n**syntax:** *rewrite_by_lua_file <path-to-lua-script-file>*\n\n**context:** *http, server, location, location if*\n\n**phase:** *rewrite tail*\n\nEquivalent to [rewrite_by_lua_block](#rewrite_by_lua_block), except that the file specified by `` contains the Lua code, or, as from the `v0.5.0rc32` release, the [LuaJIT bytecode](#luajit-bytecode-support) to be executed.\n\nNginx variables can be used in the `` string to provide flexibility. This however carries some risks and is not ordinarily recommended.\n\nWhen a relative path like `foo/bar.lua` is given, they will be turned into the absolute path relative to the `server prefix` path determined by the `-p PATH` command-line option while starting the Nginx server.\n\nWhen the Lua code cache is turned on (by default), the user code is loaded once at the first request and cached and the Nginx config must be reloaded each time the Lua source file is modified. The Lua code cache can be temporarily disabled during development by switching [lua_code_cache](#lua_code_cache) `off` in `nginx.conf` to avoid reloading Nginx.\n\nThe `rewrite_by_lua_file` code will always run at the end of the `rewrite` request-processing phase unless [rewrite_by_lua_no_postpone](#rewrite_by_lua_no_postpone) is turned on.\n\nNginx variables are supported in the file path for dynamic dispatch just as in [content_by_lua_file](#content_by_lua_file).\n\n[Back to TOC](#directives)\n\naccess_by_lua\n-------------\n\n**syntax:** *access_by_lua <lua-script-str>*\n\n**context:** *http, server, location, location if*\n\n**phase:** *access tail*\n\n**NOTE** Use of this directive is *discouraged* following the `v0.9.17` release. Use the [access_by_lua_block](#access_by_lua_block) directive instead.\n\nSimilar to the [access_by_lua_block](#access_by_lua_block) directive, but accepts the Lua source directly in an Nginx string literal (which requires\nspecial character escaping).\n\nFor instance,\n\n```nginx\n\n access_by_lua '\n do_something(\"hello, world!\\nhiya\\n\")\n ';\n```\n\n[Back to TOC](#directives)\n\naccess_by_lua_block\n-------------------\n\n**syntax:** *access_by_lua_block { lua-script }*\n\n**context:** *http, server, location, location if*\n\n**phase:** *access tail*\n\nActs as an access phase handler and executes Lua code string specified in `{ = 200 (`ngx.HTTP_OK`) and status < 300 (`ngx.HTTP_SPECIAL_RESPONSE`) for successful quits and `ngx.exit(ngx.HTTP_INTERNAL_SERVER_ERROR)` (or its friends) for failures.\n\nStarting from the `v0.9.20` release, you can use the [access_by_lua_no_postpone](#access_by_lua_no_postpone)\ndirective to control when to run this handler inside the \"access\" request-processing phase\nof Nginx.\n\nThis directive was first introduced in the `v0.9.17` release.\n\n[Back to TOC](#directives)\n\naccess_by_lua_file\n------------------\n\n**syntax:** *access_by_lua_file <path-to-lua-script-file>*\n\n**context:** *http, server, location, location if*\n\n**phase:** *access tail*\n\nEquivalent to [access_by_lua_block](#access_by_lua_block), except that the file specified by `` contains the Lua code, or, as from the `v0.5.0rc32` release, the [LuaJIT bytecode](#luajit-bytecode-support) to be executed.\n\nNginx variables can be used in the `` string to provide flexibility. This however carries some risks and is not ordinarily recommended.\n\nWhen a relative path like `foo/bar.lua` is given, they will be turned into the absolute path relative to the `server prefix` path determined by the `-p PATH` command-line option while starting the Nginx server.\n\nWhen the Lua code cache is turned on (by default), the user code is loaded once at the first request and cached\nand the Nginx config must be reloaded each time the Lua source file is modified.\nThe Lua code cache can be temporarily disabled during development by switching [lua_code_cache](#lua_code_cache) `off` in `nginx.conf` to avoid repeatedly reloading Nginx.\n\nNginx variables are supported in the file path for dynamic dispatch just as in [content_by_lua_file](#content_by_lua_file).\n\n[Back to TOC](#directives)\n\nheader_filter_by_lua\n--------------------\n\n**syntax:** *header_filter_by_lua <lua-script-str>*\n\n**context:** *http, server, location, location if*\n\n**phase:** *output-header-filter*\n\n**NOTE** Use of this directive is *discouraged* following the `v0.9.17` release. Use the [header_filter_by_lua_block](#header_filter_by_lua_block) directive instead.\n\nSimilar to the [header_filter_by_lua_block](#header_filter_by_lua_block) directive, but accepts the Lua source directly in an Nginx string literal (which requires\nspecial character escaping).\n\nFor instance,\n\n```nginx\n\n header_filter_by_lua '\n ngx.header[\"content-length\"] = nil\n ';\n```\n\nThis directive was first introduced in the `v0.2.1rc20` release.\n\n[Back to TOC](#directives)\n\nheader_filter_by_lua_block\n--------------------------\n\n**syntax:** *header_filter_by_lua_block { lua-script }*\n\n**context:** *http, server, location, location if*\n\n**phase:** *output-header-filter*\n\nUses Lua code specified in `{ lua-script }` to define an output header filter.\n\nNote that the following API functions are currently disabled within this context:\n\n* Output API functions (e.g., [ngx.say](#ngxsay) and [ngx.send_headers](#ngxsend_headers))\n* Control API functions (e.g., [ngx.redirect](#ngxredirect) and [ngx.exec](#ngxexec))\n* Subrequest API functions (e.g., [ngx.location.capture](#ngxlocationcapture) and [ngx.location.capture_multi](#ngxlocationcapture_multi))\n* Cosocket API functions (e.g., [ngx.socket.tcp](#ngxsockettcp) and [ngx.req.socket](#ngxreqsocket)).\n\nHere is an example of overriding a response header (or adding one if absent) in our Lua header filter:\n\n```nginx\n\n location / {\n proxy_pass http://mybackend;\n header_filter_by_lua_block {\n ngx.header.Foo = \"blah\"\n }\n }\n```\n\nThis directive was first introduced in the `v0.9.17` release.\n\n[Back to TOC](#directives)\n\nheader_filter_by_lua_file\n-------------------------\n\n**syntax:** *header_filter_by_lua_file <path-to-lua-script-file>*\n\n**context:** *http, server, location, location if*\n\n**phase:** *output-header-filter*\n\nEquivalent to [header_filter_by_lua_block](#header_filter_by_lua_block), except that the file specified by `` contains the Lua code, or as from the `v0.5.0rc32` release, the [LuaJIT bytecode](#luajit-bytecode-support) to be executed.\n\nWhen a relative path like `foo/bar.lua` is given, they will be turned into the absolute path relative to the `server prefix` path determined by the `-p PATH` command-line option while starting the Nginx server.\n\nThis directive was first introduced in the `v0.2.1rc20` release.\n\n[Back to TOC](#directives)\n\nbody_filter_by_lua\n------------------\n\n**syntax:** *body_filter_by_lua <lua-script-str>*\n\n**context:** *http, server, location, location if*\n\n**phase:** *output-body-filter*\n\n**NOTE** Use of this directive is *discouraged* following the `v0.9.17` release. Use the [body_filter_by_lua_block](#body_filter_by_lua_block) directive instead.\n\nSimilar to the [body_filter_by_lua_block](#body_filter_by_lua_block) directive, but accepts the Lua source directly in an Nginx string literal (which requires\nspecial character escaping).\n\nFor instance,\n\n```nginx\n\n body_filter_by_lua '\n local data, eof = ngx.arg[1], ngx.arg[2]\n ';\n```\n\nThis directive was first introduced in the `v0.5.0rc32` release.\n\n[Back to TOC](#directives)\n\nbody_filter_by_lua_block\n------------------------\n\n**syntax:** *body_filter_by_lua_block { lua-script-str }*\n\n**context:** *http, server, location, location if*\n\n**phase:** *output-body-filter*\n\nUses Lua code specified in `{ lua-script }` to define an output body filter.\n\nThe input data chunk is passed via [ngx.arg](#ngxarg)\\[1\\] (as a Lua string value) and the \"eof\" flag indicating the end of the response body data stream is passed via [ngx.arg](#ngxarg)\\[2\\] (as a Lua boolean value).\n\nBehind the scene, the \"eof\" flag is just the `last_buf` (for main requests) or `last_in_chain` (for subrequests) flag of the Nginx chain link buffers. (Before the `v0.7.14` release, the \"eof\" flag does not work at all in subrequests.)\n\nThe output data stream can be aborted immediately by running the following Lua statement:\n\n```lua\n\n return ngx.ERROR\n```\n\nThis will truncate the response body and usually result in incomplete and also invalid responses.\n\nThe Lua code can pass its own modified version of the input data chunk to the downstream Nginx output body filters by overriding [ngx.arg](#ngxarg)\\[1\\] with a Lua string or a Lua table of strings. For example, to transform all the lowercase letters in the response body, we can just write:\n\n```nginx\n\n location / {\n proxy_pass http://mybackend;\n body_filter_by_lua_block {\n ngx.arg[1] = string.upper(ngx.arg[1])\n }\n }\n```\n\nWhen setting `nil` or an empty Lua string value to `ngx.arg[1]`, no data chunk will be passed to the downstream Nginx output filters at all.\n\nLikewise, new \"eof\" flag can also be specified by setting a boolean value to [ngx.arg](#ngxarg)\\[2\\]. For example,\n\n```nginx\n\n location /t {\n echo hello world;\n echo hiya globe;\n\n body_filter_by_lua_block {\n local chunk = ngx.arg[1]\n if string.match(chunk, \"hello\") then\n ngx.arg[2] = true -- new eof\n return\n end\n\n -- just throw away any remaining chunk data\n ngx.arg[1] = nil\n }\n }\n```\n\nThen `GET /t` will just return the output\n\n\n hello world\n\n\nThat is, when the body filter sees a chunk containing the word \"hello\", then it will set the \"eof\" flag to true immediately, resulting in truncated but still valid responses.\n\nWhen the Lua code may change the length of the response body, then it is required to always clear out the `Content-Length` response header (if any) in a header filter to enforce streaming output, as in\n\n```nginx\n\n location /foo {\n # fastcgi_pass/proxy_pass/...\n\n header_filter_by_lua_block {\n ngx.header.content_length = nil\n }\n body_filter_by_lua_block {\n ngx.arg[1] = string.len(ngx.arg[1]) .. \"\\n\"\n }\n }\n```\n\nNote that the following API functions are currently disabled within this context due to the limitations in Nginx output filter's current implementation:\n\n* Output API functions (e.g., [ngx.say](#ngxsay) and [ngx.send_headers](#ngxsend_headers))\n* Control API functions (e.g., [ngx.exit](#ngxexit) and [ngx.exec](#ngxexec))\n* Subrequest API functions (e.g., [ngx.location.capture](#ngxlocationcapture) and [ngx.location.capture_multi](#ngxlocationcapture_multi))\n* Cosocket API functions (e.g., [ngx.socket.tcp](#ngxsockettcp) and [ngx.req.socket](#ngxreqsocket)).\n\nNginx output filters may be called multiple times for a single request because response body may be delivered in chunks. Thus, the Lua code specified by in this directive may also run multiple times in the lifetime of a single HTTP request.\n\nThis directive was first introduced in the `v0.9.17` release.\n\n[Back to TOC](#directives)\n\nbody_filter_by_lua_file\n-----------------------\n\n**syntax:** *body_filter_by_lua_file <path-to-lua-script-file>*\n\n**context:** *http, server, location, location if*\n\n**phase:** *output-body-filter*\n\nEquivalent to [body_filter_by_lua_block](#body_filter_by_lua_block), except that the file specified by `` contains the Lua code, or, as from the `v0.5.0rc32` release, the [LuaJIT bytecode](#luajit-bytecode-support) to be executed.\n\nWhen a relative path like `foo/bar.lua` is given, they will be turned into the absolute path relative to the `server prefix` path determined by the `-p PATH` command-line option while starting the Nginx server.\n\nThis directive was first introduced in the `v0.5.0rc32` release.\n\n[Back to TOC](#directives)\n\nlog_by_lua\n----------\n\n**syntax:** *log_by_lua <lua-script-str>*\n\n**context:** *http, server, location, location if*\n\n**phase:** *log*\n\n**NOTE** Use of this directive is *discouraged* following the `v0.9.17` release. Use the [log_by_lua_block](#log_by_lua_block) directive instead.\n\nSimilar to the [log_by_lua_block](#log_by_lua_block) directive, but accepts the Lua source directly in an Nginx string literal (which requires\nspecial character escaping).\n\nFor instance,\n\n```nginx\n\n log_by_lua '\n print(\"I need no extra escaping here, for example: \\r\\nblah\")\n ';\n```\n\nThis directive was first introduced in the `v0.5.0rc31` release.\n\n[Back to TOC](#directives)\n\nlog_by_lua_block\n----------------\n\n**syntax:** *log_by_lua_block { lua-script }*\n\n**context:** *http, server, location, location if*\n\n**phase:** *log*\n\nRuns the Lua source code inlined as the `{ lua-script }` at the `log` request processing phase. This does not replace the current access logs, but runs before.\n\nNote that the following API functions are currently disabled within this context:\n\n* Output API functions (e.g., [ngx.say](#ngxsay) and [ngx.send_headers](#ngxsend_headers))\n* Control API functions (e.g., [ngx.exit](#ngxexit))\n* Subrequest API functions (e.g., [ngx.location.capture](#ngxlocationcapture) and [ngx.location.capture_multi](#ngxlocationcapture_multi))\n* Cosocket API functions (e.g., [ngx.socket.tcp](#ngxsockettcp) and [ngx.req.socket](#ngxreqsocket)).\n\nHere is an example of gathering average data for [$upstream_response_time](http://nginx.org/en/docs/http/ngx_http_upstream_module.html#var_upstream_response_time):\n\n```nginx\n\n lua_shared_dict log_dict 5M;\n\n server {\n location / {\n proxy_pass http://mybackend;\n\n log_by_lua_block {\n local log_dict = ngx.shared.log_dict\n local upstream_time = tonumber(ngx.var.upstream_response_time)\n\n local sum = log_dict:get(\"upstream_time-sum\") or 0\n sum = sum + upstream_time\n log_dict:set(\"upstream_time-sum\", sum)\n\n local newval, err = log_dict:incr(\"upstream_time-nb\", 1)\n if not newval and err == \"not found\" then\n log_dict:add(\"upstream_time-nb\", 0)\n log_dict:incr(\"upstream_time-nb\", 1)\n end\n }\n }\n\n location = /status {\n content_by_lua_block {\n local log_dict = ngx.shared.log_dict\n local sum = log_dict:get(\"upstream_time-sum\")\n local nb = log_dict:get(\"upstream_time-nb\")\n\n if nb and sum then\n ngx.say(\"average upstream response time: \", sum / nb,\n \" (\", nb, \" reqs)\")\n else\n ngx.say(\"no data yet\")\n end\n }\n }\n }\n```\n\nThis directive was first introduced in the `v0.9.17` release.\n\n[Back to TOC](#directives)\n\nlog_by_lua_file\n---------------\n\n**syntax:** *log_by_lua_file <path-to-lua-script-file>*\n\n**context:** *http, server, location, location if*\n\n**phase:** *log*\n\nEquivalent to [log_by_lua_block](#log_by_lua_block), except that the file specified by `` contains the Lua code, or, as from the `v0.5.0rc32` release, the [LuaJIT bytecode](#luajit-bytecode-support) to be executed.\n\nWhen a relative path like `foo/bar.lua` is given, they will be turned into the absolute path relative to the `server prefix` path determined by the `-p PATH` command-line option while starting the Nginx server.\n\nThis directive was first introduced in the `v0.5.0rc31` release.\n\n[Back to TOC](#directives)\n\nbalancer_by_lua_block\n---------------------\n\n**syntax:** *balancer_by_lua_block { lua-script }*\n\n**context:** *upstream*\n\n**phase:** *content*\n\nThis directive runs Lua code as an upstream balancer for any upstream entities defined\nby the `upstream {}` configuration block.\n\nFor instance,\n\n```nginx\n\n upstream foo {\n server 127.0.0.1;\n balancer_by_lua_block {\n -- use Lua to do something interesting here\n -- as a dynamic balancer\n }\n }\n\n server {\n location / {\n proxy_pass http://foo;\n }\n }\n```\n\nThe resulting Lua load balancer can work with any existing Nginx upstream modules\nlike [ngx_proxy](https://nginx.org/en/docs/http/ngx_http_proxy_module.html) and\n[ngx_fastcgi](https://nginx.org/en/docs/http/ngx_http_fastcgi_module.html).\n\nAlso, the Lua load balancer can work with the standard upstream connection pool mechanism,\ni.e., the standard [keepalive](https://nginx.org/en/docs/http/ngx_http_upstream_module.html#keepalive) directive.\nJust ensure that the [keepalive](https://nginx.org/en/docs/http/ngx_http_upstream_module.html#keepalive) directive\nis used *after* this `balancer_by_lua_block` directive in a single `upstream {}` configuration block.\n\nThe Lua load balancer can totally ignore the list of servers defined in the `upstream {}` block\nand select peer from a completely dynamic server list (even changing per request) via the\n[ngx.balancer](https://github.com/openresty/lua-resty-core/blob/master/lib/ngx/balancer.md) module\nfrom the [lua-resty-core](https://github.com/openresty/lua-resty-core) library.\n\nThe Lua code handler registered by this directive might get called more than once in a single\ndownstream request when the Nginx upstream mechanism retries the request on conditions\nspecified by directives like the [proxy_next_upstream](https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_next_upstream)\ndirective.\n\nThis Lua code execution context does not support yielding, so Lua APIs that may yield\n(like cosockets and \"light threads\") are disabled in this context. One can usually work\naround this limitation by doing such operations in an earlier phase handler (like\n[precontent_by_lua*](#precontent_by_lua_block)) and passing along the result into this context\nvia the [ngx.ctx](#ngxctx) table.\n\nThis directive was first introduced in the `v0.10.0` release.\n\n[Back to TOC](#directives)\n\nbalancer_by_lua_file\n--------------------\n\n**syntax:** *balancer_by_lua_file <path-to-lua-script-file>*\n\n**context:** *upstream*\n\n**phase:** *content*\n\nEquivalent to [balancer_by_lua_block](#balancer_by_lua_block), except that the file specified by `` contains the Lua code, or, as from the `v0.5.0rc32` release, the [LuaJIT bytecode](#luajit-bytecode-support) to be executed.\n\nWhen a relative path like `foo/bar.lua` is given, they will be turned into the absolute path relative to the `server prefix` path determined by the `-p PATH` command-line option while starting the Nginx server.\n\nThis directive was first introduced in the `v0.10.0` release.\n\n[Back to TOC](#directives)\n\nbalancer_keepalive\n------------------\n\n**syntax:** *balancer_keepalive <total-connections>*\n\n**context:** *upstream*\n\n**phase:** *loading-config*\n\nThe `total-connections` parameter sets the maximum number of idle\nkeepalive connections to upstream servers that are preserved in the cache of\neach worker process. When this number is exceeded, the least recently used\nconnections are closed.\n\nIt should be particularly noted that the keepalive directive does not limit the\ntotal number of connections to upstream servers that an nginx worker process\ncan open. The connections parameter should be set to a number small enough to\nlet upstream servers process new incoming connections as well.\n\nThis directive was first introduced in the `v0.10.21` release.\n\n[Back to TOC](#directives)\n\nlua_need_request_body\n---------------------\n\n**syntax:** *lua_need_request_body <on|off>*\n\n**default:** *off*\n\n**context:** *http, server, location, location if*\n\n**phase:** *depends on usage*\n\nDetermines whether to force the request body data to be read before running rewrite/access/content_by_lua* or not. The Nginx core does not read the client request body by default and if request body data is required, then this directive should be turned `on` or the [ngx.req.read_body](#ngxreqread_body) function should be called within the Lua code.\n\nTo read the request body data within the [$request_body](http://nginx.org/en/docs/http/ngx_http_core_module.html#var_request_body) variable,\n[client_body_buffer_size](http://nginx.org/en/docs/http/ngx_http_core_module.html#client_body_buffer_size) must have the same value as [client_max_body_size](http://nginx.org/en/docs/http/ngx_http_core_module.html#client_max_body_size). Because when the content length exceeds [client_body_buffer_size](http://nginx.org/en/docs/http/ngx_http_core_module.html#client_body_buffer_size) but less than [client_max_body_size](http://nginx.org/en/docs/http/ngx_http_core_module.html#client_max_body_size), Nginx will buffer the data into a temporary file on the disk, which will lead to empty value in the [$request_body](http://nginx.org/en/docs/http/ngx_http_core_module.html#var_request_body) variable.\n\nIf the current location includes [rewrite_by_lua*](#rewrite_by_lua) directives,\nthen the request body will be read just before the [rewrite_by_lua*](#rewrite_by_lua) code is run (and also at the\n`rewrite` phase). Similarly, if only [content_by_lua](#content_by_lua) is specified,\nthe request body will not be read until the content handler's Lua code is\nabout to run (i.e., the request body will be read during the content phase).\n\nIt is recommended however, to use the [ngx.req.read_body](#ngxreqread_body) and [ngx.req.discard_body](#ngxreqdiscard_body) functions for finer control over the request body reading process instead.\n\nThis also applies to [access_by_lua*](#access_by_lua).\n\n[Back to TOC](#directives)\n\nssl_client_hello_by_lua_block\n-----------------------------\n\n**syntax:** *ssl_client_hello_by_lua_block { lua-script }*\n\n**context:** *http, server*\n\n**phase:** *right-after-client-hello-message-was-processed*\n\nThis directive runs user Lua code when Nginx is about to post-process the SSL client hello message for the downstream\nSSL (https) connections.\n\nIt is particularly useful for dynamically setting the SSL protocols according to the SNI.\n\nIt is also useful to do some custom operations according to the per-connection information in the client hello message.\n\nFor example, one can parse custom client hello extension and do the corresponding handling in pure Lua.\n\nThis Lua handler will always run whether the SSL session is resumed (via SSL session IDs or TLS session tickets) or not.\nWhile the `ssl_certificate_by_lua*` Lua handler will only runs when initiating a full SSL handshake.\n\nThe [ngx.ssl.clienthello](https://github.com/openresty/lua-resty-core/blob/master/lib/ngx/ssl/clienthello.md) Lua modules\nprovided by the [lua-resty-core](https://github.com/openresty/lua-resty-core/#readme)\nlibrary are particularly useful in this context.\n\nNote that this handler runs in extremely early stage of SSL handshake, before the SSL client hello extensions are parsed.\nSo you can not use some Lua API like `ssl.server_name()` which is dependent on the later stage's processing.\n\nAlso note that only the directive in default server is valid for several virtual servers with the same IP address and port.\n\nBelow is a trivial example using the\n[ngx.ssl.clienthello](https://github.com/openresty/lua-resty-core/blob/master/lib/ngx/ssl/clienthello.md) module\nat the same time:\n\n```nginx\n\n server {\n listen 443 ssl;\n server_name test.com;\n ssl_certificate /path/to/cert.crt;\n ssl_certificate_key /path/to/key.key;\n ssl_client_hello_by_lua_block {\n local ssl_clt = require \"ngx.ssl.clienthello\"\n local host, err = ssl_clt.get_client_hello_server_name()\n if host == \"test.com\" then\n ssl_clt.set_protocols({\"TLSv1\", \"TLSv1.1\"})\n elseif host == \"test2.com\" then\n ssl_clt.set_protocols({\"TLSv1.2\", \"TLSv1.3\"})\n elseif not host then\n ngx.log(ngx.ERR, \"failed to get the SNI name: \", err)\n ngx.exit(ngx.ERROR)\n else\n ngx.log(ngx.ERR, \"unknown SNI name: \", host)\n ngx.exit(ngx.ERROR)\n end\n }\n ...\n }\n server {\n listen 443 ssl;\n server_name test2.com;\n ssl_certificate /path/to/cert.crt;\n ssl_certificate_key /path/to/key.key;\n ...\n }\n```\n\nSee more information in the [ngx.ssl.clienthello](https://github.com/openresty/lua-resty-core/blob/master/lib/ngx/ssl/clienthello.md)\nLua modules' official documentation.\n\nUncaught Lua exceptions in the user Lua code immediately abort the current SSL session, so does the\n[ngx.exit](#ngxexit) call with an error code like `ngx.ERROR`.\n\nThis Lua code execution context *does* support yielding, so Lua APIs that may yield\n(like cosockets, sleeping, and \"light threads\")\nare enabled in this context\n\nNote, you need to configure the [ssl_certificate](https://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_certificate)\nand [ssl_certificate_key](https://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_certificate_key)\nto avoid the following error while starting NGINX:\n\n\n nginx: [emerg] no ssl configured for the server\n\n\nThis directive requires OpenSSL 1.1.1 or greater.\n\nIf you are using the [official pre-built\npackages](https://openresty.org/en/linux-packages.html) for\n[OpenResty](https://openresty.org/) 1.21.4.1 or later, then everything should\nwork out of the box.\n\nIf you are not using the Nginx core shipped with\n[OpenResty](https://openresty.org) 1.21.4.1 or later, you will need to apply\npatches to the standard Nginx core:\n\n\n\n**Note for HTTP/3 (QUIC) users**: When using this directive with HTTP/3 connections, certain yield operations may fail if the QUIC SSL Lua yield patch is not applied to your OpenSSL installation. OpenResty packages include this patch by default, but if you are building lua-nginx-module separately, you may need to apply the patch manually to ensure proper yield/resume functionality for HTTP/3 connections in SSL Lua phases. The patch can be found at: [nginx-1.27.1-quic_ssl_lua_yield.patch](https://github.com/openresty/openresty/blob/master/patches/nginx/1.27.1/nginx-1.27.1-quic_ssl_lua_yield.patch)\n\nThis directive was first introduced in the `v0.10.21` release.\n\n[Back to TOC](#directives)\n\nssl_client_hello_by_lua_file\n----------------------------\n\n**syntax:** *ssl_client_hello_by_lua_file <path-to-lua-script-file>*\n\n**context:** *http, server*\n\n**phase:** *right-after-client-hello-message-was-processed*\n\nEquivalent to [ssl_client_hello_by_lua_block](#ssl_client_hello_by_lua_block), except that the file specified by `` contains the Lua code, or, as from the `v0.5.0rc32` release, the [LuaJIT bytecode](#luajit-bytecode-support) to be executed.\n\nWhen a relative path like `foo/bar.lua` is given, they will be turned into the absolute path relative to the `server prefix` path determined by the `-p PATH` command-line option while starting the Nginx server.\n\n**Note for HTTP/3 (QUIC) users**: When using this directive with HTTP/3 connections, certain yield operations may fail if the QUIC SSL Lua yield patch is not applied to your OpenSSL installation. OpenResty packages include this patch by default, but if you are building lua-nginx-module separately, you may need to apply the patch manually to ensure proper yield/resume functionality for HTTP/3 connections in SSL Lua phases. The patch can be found at: [nginx-1.27.1-quic_ssl_lua_yield.patch](https://github.com/openresty/openresty/blob/master/patches/nginx/1.27.1/nginx-1.27.1-quic_ssl_lua_yield.patch)\n\nThis directive was first introduced in the `v0.10.21` release.\n\n[Back to TOC](#directives)\n\nssl_certificate_by_lua_block\n----------------------------\n\n**syntax:** *ssl_certificate_by_lua_block { lua-script }*\n\n**context:** *server*\n\n**phase:** *right-before-SSL-handshake*\n\nThis directive runs user Lua code when Nginx is about to start the SSL handshake for the downstream\nSSL (https) connections.\n\nIt is particularly useful for setting the SSL certificate chain and the corresponding private key on a per-request\nbasis. It is also useful to load such handshake configurations nonblockingly from the remote (for example,\nwith the [cosocket](#ngxsockettcp) API). And one can also do per-request OCSP stapling handling in pure\nLua here as well.\n\nAnother typical use case is to do SSL handshake traffic control nonblockingly in this context,\nwith the help of the [lua-resty-limit-traffic#readme](https://github.com/openresty/lua-resty-limit-traffic)\nlibrary, for example.\n\nOne can also do interesting things with the SSL handshake requests from the client side, like\nrejecting old SSL clients using the SSLv3 protocol or even below selectively.\n\nThe [ngx.ssl](https://github.com/openresty/lua-resty-core/blob/master/lib/ngx/ssl.md)\nand [ngx.ocsp](https://github.com/openresty/lua-resty-core/blob/master/lib/ngx/ocsp.md) Lua modules\nprovided by the [lua-resty-core](https://github.com/openresty/lua-resty-core/#readme)\nlibrary are particularly useful in this context. You can use the Lua API offered by these two Lua modules\nto manipulate the SSL certificate chain and private key for the current SSL connection\nbeing initiated.\n\nThis Lua handler does not run at all, however, when Nginx/OpenSSL successfully resumes\nthe SSL session via SSL session IDs or TLS session tickets for the current SSL connection. In\nother words, this Lua handler only runs when Nginx has to initiate a full SSL handshake.\n\nBelow is a trivial example using the\n[ngx.ssl](https://github.com/openresty/lua-resty-core/blob/master/lib/ngx/ssl.md) module\nat the same time:\n\n```nginx\n\n server {\n listen 443 ssl;\n server_name test.com;\n\n ssl_certificate_by_lua_block {\n print(\"About to initiate a new SSL handshake!\")\n }\n\n location / {\n root html;\n }\n }\n```\n\nSee more complicated examples in the [ngx.ssl](https://github.com/openresty/lua-resty-core/blob/master/lib/ngx/ssl.md)\nand [ngx.ocsp](https://github.com/openresty/lua-resty-core/blob/master/lib/ngx/ocsp.md)\nLua modules' official documentation.\n\nUncaught Lua exceptions in the user Lua code immediately abort the current SSL session, so does the\n[ngx.exit](#ngxexit) call with an error code like `ngx.ERROR`.\n\nThis Lua code execution context *does* support yielding, so Lua APIs that may yield\n(like cosockets, sleeping, and \"light threads\")\nare enabled in this context.\n\nNote, however, you still need to configure the [ssl_certificate](https://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_certificate) and\n[ssl_certificate_key](https://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_certificate_key)\ndirectives even though you will not use this static certificate and private key at all. This is\nbecause the NGINX core requires their appearance otherwise you are seeing the following error\nwhile starting NGINX:\n\n\n nginx: [emerg] no ssl configured for the server\n\n\nThis directive requires OpenSSL 1.0.2e or greater.\n\nIf you are using the [official pre-built\npackages](https://openresty.org/en/linux-packages.html) for\n[OpenResty](https://openresty.org/) 1.9.7.2 or later, then everything should\nwork out of the box.\n\nIf you are not using the Nginx core shipped with\n[OpenResty](https://openresty.org) 1.9.7.2 or later, you will need to apply\npatches to the standard Nginx core:\n\n\n\n**Note for HTTP/3 (QUIC) users**: When using this directive with HTTP/3 connections, certain yield operations may fail if the QUIC SSL Lua yield patch is not applied to your OpenSSL installation. OpenResty packages include this patch by default, but if you are building lua-nginx-module separately, you may need to apply the patch manually to ensure proper yield/resume functionality for HTTP/3 connections in SSL Lua phases. The patch can be found at: [nginx-1.27.1-quic_ssl_lua_yield.patch](https://github.com/openresty/openresty/blob/master/patches/nginx/1.27.1/nginx-1.27.1-quic_ssl_lua_yield.patch)\n\nThis directive was first introduced in the `v0.10.0` release.\n\n[Back to TOC](#directives)\n\nssl_certificate_by_lua_file\n---------------------------\n\n**syntax:** *ssl_certificate_by_lua_file <path-to-lua-script-file>*\n\n**context:** *server*\n\n**phase:** *right-before-SSL-handshake*\n\nEquivalent to [ssl_certificate_by_lua_block](#ssl_certificate_by_lua_block), except that the file specified by `` contains the Lua code, or, as from the `v0.5.0rc32` release, the [LuaJIT bytecode](#luajit-bytecode-support) to be executed.\n\nWhen a relative path like `foo/bar.lua` is given, they will be turned into the absolute path relative to the `server prefix` path determined by the `-p PATH` command-line option while starting the Nginx server.\n\n**Note for HTTP/3 (QUIC) users**: When using this directive with HTTP/3 connections, certain yield operations may fail if the QUIC SSL Lua yield patch is not applied to your OpenSSL installation. OpenResty packages include this patch by default, but if you are building lua-nginx-module separately, you may need to apply the patch manually to ensure proper yield/resume functionality for HTTP/3 connections in SSL Lua phases. The patch can be found at: [nginx-1.27.1-quic_ssl_lua_yield.patch](https://github.com/openresty/openresty/blob/master/patches/nginx/1.27.1/nginx-1.27.1-quic_ssl_lua_yield.patch)\n\nThis directive was first introduced in the `v0.10.0` release.\n\n[Back to TOC](#directives)\n\nssl_session_fetch_by_lua_block\n------------------------------\n\n**syntax:** *ssl_session_fetch_by_lua_block { lua-script }*\n\n**context:** *http*\n\n**phase:** *right-before-SSL-handshake*\n\nThis directive runs Lua code to look up and load the SSL session (if any) according to the session ID\nprovided by the current SSL handshake request for the downstream.\n\nThe Lua API for obtaining the current session ID and loading a cached SSL session data\nis provided in the [ngx.ssl.session](https://github.com/openresty/lua-resty-core/blob/master/lib/ngx/ssl/session.md)\nLua module shipped with the [lua-resty-core](https://github.com/openresty/lua-resty-core#readme)\nlibrary.\n\nLua APIs that may yield, like [ngx.sleep](#ngxsleep) and [cosockets](#ngxsockettcp),\nare enabled in this context.\n\nThis hook, together with the [ssl_session_store_by_lua*](#ssl_session_store_by_lua_block) hook,\ncan be used to implement distributed caching mechanisms in pure Lua (based\non the [cosocket](#ngxsockettcp) API, for example). If a cached SSL session is found\nand loaded into the current SSL connection context,\nSSL session resumption can then get immediately initiated and bypass the full SSL handshake process which is very expensive in terms of CPU time.\n\nPlease note that TLS session tickets are very different and it is the clients' responsibility\nto cache the SSL session state when session tickets are used. SSL session resumptions based on\nTLS session tickets would happen automatically without going through this hook (nor the\n[ssl_session_store_by_lua*](#ssl_session_store_by_lua_block) hook). This hook is mainly\nfor older or less capable SSL clients that can only do SSL sessions by session IDs.\n\nWhen [ssl_certificate_by_lua*](#ssl_certificate_by_lua_block) is specified at the same time,\nthis hook usually runs before [ssl_certificate_by_lua*](#ssl_certificate_by_lua_block).\nWhen the SSL session is found and successfully loaded for the current SSL connection,\nSSL session resumption will happen and thus bypass the [ssl_certificate_by_lua*](#ssl_certificate_by_lua_block)\nhook completely. In this case, Nginx also bypasses the [ssl_session_store_by_lua*](#ssl_session_store_by_lua_block)\nhook, for obvious reasons.\n\nTo easily test this hook locally with a modern web browser, you can temporarily put the following line\nin your https server block to disable the TLS session ticket support:\n\n ssl_session_tickets off;\n\nBut do not forget to comment this line out before publishing your site to the world.\n\nIf you are using the [official pre-built packages](https://openresty.org/en/linux-packages.html) for [OpenResty](https://openresty.org/)\n1.11.2.1 or later, then everything should work out of the box.\n\nIf you are not using one of the [OpenSSL\npackages](https://openresty.org/en/linux-packages.html) provided by\n[OpenResty](https://openresty.org), you will need to apply patches to OpenSSL\nin order to use this directive:\n\n\n\nSimilarly, if you are not using the Nginx core shipped with\n[OpenResty](https://openresty.org) 1.11.2.1 or later, you will need to apply\npatches to the standard Nginx core:\n\n\n\nThis directive was first introduced in the `v0.10.6` release.\n\nNote that this directive can only be used in the **http context** starting\nwith the `v0.10.7` release since SSL session resumption happens\nbefore server name dispatch.\n\n[Back to TOC](#directives)\n\nssl_session_fetch_by_lua_file\n-----------------------------\n\n**syntax:** *ssl_session_fetch_by_lua_file <path-to-lua-script-file>*\n\n**context:** *http*\n\n**phase:** *right-before-SSL-handshake*\n\nEquivalent to [ssl_session_fetch_by_lua_block](#ssl_session_fetch_by_lua_block), except that the file specified by `` contains the Lua code, or rather, the [LuaJIT bytecode](#luajit-bytecode-support) to be executed.\n\nWhen a relative path like `foo/bar.lua` is given, they will be turned into the absolute path relative to the `server prefix` path determined by the `-p PATH` command-line option while starting the Nginx server.\n\nThis directive was first introduced in the `v0.10.6` release.\n\nNote that: this directive is only allowed to used in **http context** from the `v0.10.7` release\n(because SSL session resumption happens before server name dispatch).\n\n[Back to TOC](#directives)\n\nssl_session_store_by_lua_block\n------------------------------\n\n**syntax:** *ssl_session_store_by_lua_block { lua-script }*\n\n**context:** *http*\n\n**phase:** *right-after-SSL-handshake*\n\nThis directive runs Lua code to fetch and save the SSL session (if any) according to the session ID\nprovided by the current SSL handshake request for the downstream. The saved or cached SSL\nsession data can be used for future SSL connections to resume SSL sessions without going\nthrough the full SSL handshake process (which is very expensive in terms of CPU time).\n\nLua APIs that may yield, like [ngx.sleep](#ngxsleep) and [cosockets](#ngxsockettcp),\nare *disabled* in this context. You can still, however, use the [ngx.timer.at](#ngxtimerat) API\nto create 0-delay timers to save the SSL session data asynchronously to external services (like `redis` or `memcached`).\n\nThe Lua API for obtaining the current session ID and the associated session state data\nis provided in the [ngx.ssl.session](https://github.com/openresty/lua-resty-core/blob/master/lib/ngx/ssl/session.md#readme)\nLua module shipped with the [lua-resty-core](https://github.com/openresty/lua-resty-core#readme)\nlibrary.\n\nTo easily test this hook locally with a modern web browser, you can temporarily put the following line\nin your https server block to disable the TLS session ticket support:\n\n ssl_session_tickets off;\n\nBut do not forget to comment this line out before publishing your site to the world.\n\nThis directive was first introduced in the `v0.10.6` release.\n\nNote that: this directive is only allowed to used in **http context** from the `v0.10.7` release\n(because SSL session resumption happens before server name dispatch).\n\n[Back to TOC](#directives)\n\nssl_session_store_by_lua_file\n-----------------------------\n\n**syntax:** *ssl_session_store_by_lua_file <path-to-lua-script-file>*\n\n**context:** *http*\n\n**phase:** *right-after-SSL-handshake*\n\nEquivalent to [ssl_session_store_by_lua_block](#ssl_session_store_by_lua_block), except that the file specified by `` contains the Lua code, or rather, the [LuaJIT bytecode](#luajit-bytecode-support) to be executed.\n\nWhen a relative path like `foo/bar.lua` is given, they will be turned into the absolute path relative to the `server prefix` path determined by the `-p PATH` command-line option while starting the Nginx server.\n\nThis directive was first introduced in the `v0.10.6` release.\n\nNote that: this directive is only allowed to used in **http context** from the `v0.10.7` release\n(because SSL session resumption happens before server name dispatch).\n\n[Back to TOC](#directives)\n\nproxy_ssl_certificate_by_lua_block\n----------------------------------\n\n**syntax:** *proxy_ssl_certificate_by_lua_block { lua-script }*\n\n**context:** *location*\n\n**phase:** *right-after-server-certificate-request-message-was-processed*\n\nThis directive runs user Lua code when Nginx is about to post-process the SSL server certificate request message from upstream. It is particularly useful for setting the SSL certificate chain and the corresponding private key for the upstream SSL (https) connections. It is also useful to load such handshake configurations nonblockingly from the remote (for example, with the [cosocket](#ngxsockettcp) API).\n\nThe [ngx.ssl.proxysslcert](https://github.com/openresty/lua-resty-core/blob/master/lib/ngx/ssl/proxysslcert.md) Lua module provided by the [lua-resty-core](https://github.com/openresty/lua-resty-core/#readme) library are particularly useful in this context.\n\nBelow is a trivial example using the [ngx.ssl](https://github.com/openresty/lua-resty-core/blob/master/lib/ngx/ssl.md) module and the [ngx.ssl.proxysslcert](https://github.com/openresty/lua-resty-core/blob/master/lib/ngx/ssl/proxysslcert.md) module at the same time:\n\n```nginx\n\n server {\n listen 443 ssl;\n server_name test.com;\n ssl_certificate /path/to/cert.crt;\n ssl_certificate_key /path/to/key.key;\n\n location /t {\n proxy_pass https://upstream;\n\n proxy_ssl_certificate_by_lua_block {\n local ssl = require \"ngx.ssl\"\n local proxy_ssl_cert = require \"ngx.ssl.proxysslcert\"\n\n -- NOTE: for illustration only, we don't handle error below\n\n local f = assert(io.open(\"/path/to/cert.crt\"))\n local cert_data = f:read(\"*a\")\n f:close()\n\n local cert, err = ssl.parse_pem_cert(cert_data)\n local ok, err = proxy_ssl_cert.set_cert(cert)\n\n local f = assert(io.open(\"/path/to/key.key\"))\n local pkey_data = f:read(\"*a\")\n f:close()\n\n local pkey, err = ssl.parse_pem_priv_key(pkey_data)\n local ok, err = proxy_ssl_cert.set_priv_key(pkey)\n -- ...\n }\n }\n ...\n }\n```\n\nSee more information in the [ngx.ssl.proxysslcert](https://github.com/openresty/lua-resty-core/blob/master/lib/ngx/ssl/proxysslcert.md) Lua module's official documentation.\n\nUncaught Lua exceptions in the user Lua code immediately abort the current SSL session, so does the\n[ngx.exit](#ngxexit) call with an error code like `ngx.ERROR`.\n\nThis Lua code execution context *does* support yielding, so Lua APIs that may yield (like cosockets, sleeping, and \"light threads\") are enabled in this context.\n\nNote that, unlike the relations between the [ssl_certificate](https://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_certificate) and [ssl_certificate_key](https://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_certificate_key) directives and [ssl_certificate_by_lua*](#ssl_certificate_by_lua_block), the [proxy_ssl_certificate](https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_ssl_certificate) and [proxy_ssl_certificate_key](https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_ssl_certificate_key) directives can be used together with [proxy_ssl_certificate_by_lua*](#proxy_ssl_certificate_by_lua_block).\n\n* When there are only [proxy_ssl_certificate](https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_ssl_certificate) and [proxy_ssl_certificate_key](https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_ssl_certificate_key) directives, the original Nginx behavior will obviously remain the same.\n\n* When there is only [proxy_ssl_certificate_by_lua*](#proxy_ssl_certificate_by_lua_block), Nginx will send the certificate and its related private key and chain set by Lua codes.\n\n* When the [proxy_ssl_certificate](https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_ssl_certificate) and [proxy_ssl_certificate_key](https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_ssl_certificate_key) directives and [proxy_ssl_certificate_by_lua*](#proxy_ssl_certificate_by_lua_block) are used at the same time, then [proxy_ssl_certificate_by_lua*](#proxy_ssl_certificate_by_lua_block) will take precedence over the [proxy_ssl_certificate](https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_ssl_certificate) and [proxy_ssl_certificate_key](https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_ssl_certificate_key) directives.\n\nPlease refer to corresponding test case file and [ngx.ssl.proxysslcert](https://github.com/openresty/lua-resty-core/blob/master/lib/ngx/ssl/proxysslcert.md) for more details.\n\nNote also that, it has the same condition as the [proxy_ssl_certificate](https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_ssl_certificate) directive for [proxy_ssl_certificate_by_lua*](#proxy_ssl_certificate_by_lua_block) to work, that is the upstream server should enable verification of client certificates.\n\nThis directive requires OpenSSL 1.0.2e or greater.\n\n[Back to TOC](#directives)\n\nproxy_ssl_certificate_by_lua_file\n---------------------------------\n\n**syntax:** *proxy_ssl_certificate_by_lua_file <path-to-lua-script-file>*\n\n**context:** *location*\n\n**phase:** *right-after-server-certificate-request-message-was-processed*\n\nEquivalent to [proxy_ssl_certificate_by_lua_block](#proxy_ssl_certificate_by_lua_block), except that the file specified by `` contains the Lua code, or, as from the `v0.5.0rc32` release, the [LuaJIT bytecode](#luajit-bytecode-support) to be executed.\n\nWhen a relative path like `foo/bar.lua` is given, they will be turned into the absolute path relative to the `server prefix` path determined by the `-p PATH` command-line option while starting the Nginx server.\n\n[Back to TOC](#directives)\n\nproxy_ssl_verify_by_lua_block\n-----------------------------\n\n**syntax:** *proxy_ssl_verify_by_lua_block { lua-script }*\n\n**context:** *location*\n\n**phase:** *right-after-server-certificate-message-was-processed*\n\nThis directive runs user Lua code when Nginx is about to post-process the SSL server certificate message for the upstream SSL (https) connections.\n\nIt is particularly useful to parse upstream server certificate and do some custom operations in pure lua.\n\nThe [ngx.ssl.proxysslverify](https://github.com/openresty/lua-resty-core/blob/master/lib/ngx/ssl/proxysslverify.md) Lua module provided by the [lua-resty-core](https://github.com/openresty/lua-resty-core/#readme)\nlibrary are particularly useful in this context.\n\nBelow is a trivial example using the\n[ngx.ssl.proxysslverify](https://github.com/openresty/lua-resty-core/blob/master/lib/ngx/ssl/proxysslverify.md) module\nat the same time:\n\n```nginx\n\n server {\n listen 443 ssl;\n server_name test.com;\n ssl_certificate /path/to/cert.crt;\n ssl_certificate_key /path/to/key.key;\n\n location /t {\n proxy_ssl_certificate /path/to/cert.crt;\n proxy_ssl_certificate_key /path/to/key.key;\n proxy_pass https://upstream;\n\n proxy_ssl_verify_by_lua_block {\n local proxy_ssl_vfy = require \"ngx.ssl.proxysslverify\"\n local cert = proxy_ssl_vfy.get_verify_cert()\n\n -- ocsp to verify cert\n -- check crl\n proxy_ssl_vfy.set_verify_result()\n ...\n }\n }\n ...\n }\n```\n\nSee more information in the [ngx.ssl.proxysslverify](https://github.com/openresty/lua-resty-core/blob/master/lib/ngx/ssl/proxysslverify.md)\nLua module's official documentation.\n\nUncaught Lua exceptions in the user Lua code immediately abort the current SSL session, so does the\n[ngx.exit](#ngxexit) call with an error code like `ngx.ERROR`.\n\nThis Lua code execution context *does* support yielding, so Lua APIs that may yield\n(like cosockets, sleeping, and \"light threads\")\nare enabled in this context\n\nThis directive requires OpenSSL 3.0.2 or greater.\n\n[Back to TOC](#directives)\n\nproxy_ssl_verify_by_lua_file\n----------------------------\n\n**syntax:** *proxy_ssl_verify_by_lua_file <path-to-lua-script-file>*\n\n**context:** *location*\n\n**phase:** *right-after-server-certificate-message-was-processed*\n\nEquivalent to [proxy_ssl_verify_by_lua_block](#proxy_ssl_verify_by_lua_block), except that the file specified by `` contains the Lua code, or, as from the `v0.5.0rc32` release, the [LuaJIT bytecode](#luajit-bytecode-support) to be executed.\n\nWhen a relative path like `foo/bar.lua` is given, they will be turned into the absolute path relative to the `server prefix` path determined by the `-p PATH` command-line option while starting the Nginx server.\n\n[Back to TOC](#directives)\n\nlua_shared_dict\n---------------\n\n**syntax:** *lua_shared_dict <name> <size>*\n\n**default:** *no*\n\n**context:** *http*\n\n**phase:** *depends on usage*\n\nDeclares a shared memory zone, ``, to serve as storage for the shm based Lua dictionary `ngx.shared.`.\n\nShared memory zones are always shared by all the Nginx worker processes in the current Nginx server instance.\n\nThe `` argument accepts size units such as `k` and `m`:\n\n```nginx\n\n http {\n lua_shared_dict dogs 10m;\n ...\n }\n```\n\nThe hard-coded minimum size is 8KB while the practical minimum size depends\non actual user data set (some people start with 12KB).\n\nSee [ngx.shared.DICT](#ngxshareddict) for details.\n\nThis directive was first introduced in the `v0.3.1rc22` release.\n\n[Back to TOC](#directives)\n\nlua_socket_connect_timeout\n--------------------------\n\n**syntax:** *lua_socket_connect_timeout <time>*\n\n**default:** *lua_socket_connect_timeout 60s*\n\n**context:** *http, server, location*\n\nThis directive controls the default timeout value used in TCP/unix-domain socket object's [connect](#tcpsockconnect) method and can be overridden by the [settimeout](#tcpsocksettimeout) or [settimeouts](#tcpsocksettimeouts) methods.\n\nThe `