=encoding utf-8



=head1 Name

ngx_stream_lua_module - Embed the power of Lua into Nginx stream/TCP Servers.

I<This module is not distributed with the Nginx source.> See L<the installation instructions>.


=head1 Status

Producty ready.

The API is still in flux and may change without notice.


=head1 Synopsis


    events {
        worker_connections 1024;
    }
    
    stream {
        # define a TCP server listening on the port 1234:
        server {
            listen 1234;
    
            content_by_lua_block {
                ngx.say("Hello, Lua!")
            }
        }
    }

Set up as an SSL TCP server:


    stream {
        server {
            listen 4343 ssl;
    
            ssl_protocols       TLSv1 TLSv1.1 TLSv1.2;
            ssl_ciphers         AES128-SHA:AES256-SHA:RC4-SHA:DES-CBC3-SHA:RC4-MD5;
            ssl_certificate     /path/to/cert.pem;
            ssl_certificate_key /path/to/cert.key;
            ssl_session_cache   shared:SSL:10m;
            ssl_session_timeout 10m;
    
            content_by_lua_block {
                local sock = assert(ngx.req.socket(true))
                local data = sock:receive()  -- read a line from downstream
                if data == "thunder!" then
                    ngx.say("flash!")  -- output data
                else
                    ngx.say("boom!")
                end
                ngx.say("the end...")
            }
        }
    }

Listening on a UNIX domain socket is also supported:


    stream {
        server {
            listen unix:/tmp/nginx.sock;
    
            content_by_lua_block {
                ngx.say("What's up?")
                ngx.flush(true)  -- flush any pending output and wait
                ngx.sleep(3)  -- sleeping for 3 sec
                ngx.say("Bye bye...")
            }
        }
    }


=head1 Description

This is a port of the L<ngx_http_lua_module|https://github.com/openresty/lua-nginx-module#readme> to the NGINX "stream" subsystem so
as to support generic stream/TCP clients in the downstream.

Lua APIs and directive names rename the same as the C<ngx_http_lua_module>.




=head2 Directives

The following directives are ported directly from C<ngx_http_lua_module>. Please check the
documentation of C<ngx_http_lua_module> for more details about their usage and behavior.


=over


=item *

L<lua_code_cache|https://github.com/openresty/lua-nginx-module#lua_code_cache>

=item *

L<lua_regex_cache_max_entries|https://github.com/openresty/lua-nginx-module#lua_regex_cache_max_entries>

=item *

L<lua_package_path|https://github.com/openresty/lua-nginx-module#lua_package_path>

=item *

L<lua_package_cpath|https://github.com/openresty/lua-nginx-module#lua_package_cpath>

=item *

L<init_by_lua_block|https://github.com/openresty/lua-nginx-module#init_by_lua_block>

=item *

L<init_by_lua_file|https://github.com/openresty/lua-nginx-module#init_by_lua_file>

=item *

L<init_worker_by_lua_block|https://github.com/openresty/lua-nginx-module#init_worker_by_lua_block>

=item *

L<init_worker_by_lua_file|https://github.com/openresty/lua-nginx-module#init_worker_by_lua_file>

=item *

L<preread_by_lua_block>

=item *

L<preread_by_lua_file>

=item *

L<content_by_lua_block|https://github.com/openresty/lua-nginx-module#content_by_lua_block>

=item *

L<content_by_lua_file|https://github.com/openresty/lua-nginx-module#content_by_lua_file>

=item *

L<balancer_by_lua_block|https://github.com/openresty/lua-nginx-module#balancer_by_lua_block>

=item *

L<balancer_by_lua_file|https://github.com/openresty/lua-nginx-module#balancer_by_lua_file>

=item *

L<log_by_lua_block>

=item *

L<log_by_lua_file>

=item *

L<lua_shared_dict|https://github.com/openresty/lua-nginx-module#lua_shared_dict>

=item *

L<lua_socket_connect_timeout|https://github.com/openresty/lua-nginx-module#lua_socket_connect_timeout>

=item *

L<lua_socket_buffer_size|https://github.com/openresty/lua-nginx-module#lua_socket_buffer_size>

=item *

L<lua_socket_pool_size|https://github.com/openresty/lua-nginx-module#lua_socket_pool_size>

=item *

L<lua_socket_keepalive_timeout|https://github.com/openresty/lua-nginx-module#lua_socket_keepalive_timeout>

=item *

L<lua_socket_log_errors|https://github.com/openresty/lua-nginx-module#lua_socket_log_errors>

=item *

L<lua_ssl_ciphers|https://github.com/openresty/lua-nginx-module#lua_ssl_ciphers>

=item *

L<lua_ssl_crl|https://github.com/openresty/lua-nginx-module#lua_ssl_crl>

=item *

L<lua_ssl_protocols|https://github.com/openresty/lua-nginx-module#lua_ssl_protocols>

=item *

L<lua_ssl_trusted_certificate|https://github.com/openresty/lua-nginx-module#lua_ssl_trusted_certificate>

=item *

L<lua_ssl_verify_depth|https://github.com/openresty/lua-nginx-module#lua_ssl_verify_depth>

=item *

L<lua_check_client_abort|https://github.com/openresty/lua-nginx-module#lua_check_client_abort>

=item *

L<lua_max_pending_timers|https://github.com/openresty/lua-nginx-module#lua_max_pending_timers>

=item *

L<lua_max_running_timers|https://github.com/openresty/lua-nginx-module#lua_max_running_timers>

=item *

L<lua_add_variable>

=item *

L<preread_by_lua_no_postpone>


=back

The L<send_timeout|http://nginx.org/r/send_timeout> directive in the Nginx "http" subsystem is missing in the "stream" subsystem.
So C<ngx_stream_lua_module> uses the C<lua_socket_send_timeout> for this purpose.

B<Note:> the lingering close directive that used to exist in older version of stream_lua_nginx_module has been removed and can
now be simulated with the newly added L<tcpsock:shutdown> method if necessary.




=head2 preread_by_lua_block

B<syntax:> I<preread_by_lua_block { lua-script }>

B<context:> I<stream, server>

B<phase:> I<preread>

Acts as a C<preread> phase handler and executes Lua code string specified in C<lua-script> for every connection
(or packet in datagram mode).
The Lua code may make L<API calls> and is executed as a new spawned coroutine in an independent global environment (i.e. a sandbox).

It is possible to acquire raw request socket using L<ngx.req.socket|https://github.com/openresty/lua-nginx-module#ngxreqsocket>
and receive data from or send data to the client. However, keep in mind that calling the C<receive()> method
of the request socket will consume the data from the buffer and those data will not be seen by handlers
further down the chain.

The C<preread_by_lua_block> code will always run at the end of the C<preread> processing phase unless
L<preread\_by\_lua\_no\_postpone> is turned on.

This directive was first introduced in the C<v0.0.3> release.




=head2 preread_by_lua_file

B<syntax:> I<preread_by_lua_file E<lt>path-to-lua-script-fileE<gt>>

B<context:> I<stream, server>

B<phase:> I<preread>

Equivalent to L<preread_by_lua_block>, except that the file specified by C<< <path-to-lua-script-file> >> contains the Lua code
or LuaJIT bytecode to be executed.

Nginx variables can be used in the C<< <path-to-lua-script-file> >> string to provide flexibility. This however carries some risks and is not ordinarily recommended.

When a relative path like C<foo/bar.lua> is given, they will be turned into the absolute path relative to the C<server prefix> path determined by the C<-p PATH> command-line option while starting the Nginx server.

When 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 L<lua_code_cache> C<off> in C<nginx.conf> to avoid reloading Nginx.

This directive was first introduced in the C<v0.0.3> release.




=head2 log_by_lua_block

B<syntax:> I<log_by_lua_block { lua-script }>

B<context:> I<stream, server>

B<phase:> I<log>

Runs the Lua source code inlined as the C<< <lua-script-str> >> at the C<log> request processing phase. This does not replace the current access logs, but runs before.

Yielding APIs in this phase, such as C<ngx.req.socket>, C<ngx.socket.*>, C<ngx.sleep>, C<ngx.say> are B<not> available in this phase.

This directive was first introduced in the C<v0.0.3> release.




=head2 log_by_lua_file

B<syntax:> I<log_by_lua_file E<lt>path-to-lua-script-fileE<gt>>

B<context:> I<stream, server>

B<phase:> I<log>

Equivalent to L<log_by_lua_block>, except that the file specified by C<< <path-to-lua-script-file> >> contains the Lua code
or LuaJIT bytecode to be executed.

Nginx variables can be used in the C<< <path-to-lua-script-file> >> string to provide flexibility. This however carries some risks and is not ordinarily recommended.

When a relative path like C<foo/bar.lua> is given, they will be turned into the absolute path relative to the C<server prefix> path determined by the C<-p PATH> command-line option while starting the Nginx server.

When 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 L<lua_code_cache> C<off> in C<nginx.conf> to avoid reloading Nginx.

This directive was first introduced in the C<v0.0.3> release.




=head2 lua_add_variable

B<syntax:> I<lua_add_variable $var>

B<context:> I<stream>

Add variable C<$var> to the stream subsystem and makes it changeable. If C<$var> already exists,
this directive will do nothing.

By default, variables added using this directive are considered "not found" and reading them
using C<ngx.var> will return C<nil>. However, they could be re-assigned using C<ngx.var> code at any time.

This directive was first introduced in the C<v0.0.4> release.




=head2 preread_by_lua_no_postpone

B<syntax:> I<preread_by_lua_no_postpone on|off>

B<context:> I<stream>

Controls whether or not to disable postponing L<preread\_by\_lua*> directives
to run at the end of the C<preread> processing phase. By default, this directive is turned off
and the Lua code is postponed to run at the end of the C<preread> phase.

This directive was first introduced in the C<v0.0.4> release.




=head2 Nginx API for Lua

Many Lua API functions are ported from the C<ngx_http_lua_module>. Check out the official manual of
C<ngx_http_lua_module> for more details on these Lua API functions.


=over


=item *

L<ngx.var.VARIABLE|https://github.com/openresty/lua-nginx-module#ngxvarvariable>


=back

This module fully supports the new variable subsystem inside the NGINX stream core. You may access any
L<built-in variables|https://nginx.org/en/docs/stream/ngx_stream_core_module.html#variables> provided by the stream core or
other stream modules.

=over


=item *

L<Core constants|https://github.com/openresty/lua-nginx-module#core-constants>

C<ngx.OK>, C<ngx.ERROR>, and etc.

=item *

L<Nginx log level constants|https://github.com/openresty/lua-nginx-module#nginx-log-level-constants>

C<ngx.ERR>, C<ngx.WARN>, and etc.

=item *

L<print|https://github.com/openresty/lua-nginx-module#print>

=item *

L<ngx.ctx|https://github.com/openresty/lua-nginx-module#ngxctx>

=item *

L<ngx.req.socket|https://github.com/openresty/lua-nginx-module#ngxreqsocket>

=item *

L<ngx.balancer|https://github.com/openresty/lua-resty-core/blob/master/lib/ngx/balancer.md>


=back

Only raw request sockets are supported, for obvious reasons. The C<raw> argument value
is ignored and the raw request socket is always returned. Unlike C<ngx_http_lua_module>,
you can still call output API functions like C<ngx.say>, C<ngx.print>, and C<ngx.flush>
after acquiring the raw request socket via this function.

When stream server is in UDP mode, reading from the downstream socket returned by the
C<ngx.req.socket> call will only return the content of a single packet. Therefore
the reading call will never block and will return C<nil, "no more data"> when all the
data from the datagram has been consumed. However, you may choose to send multiple UDP
packets back to the client using the downstream socket.

Raw TCP request socket returned by this module will contain the following extra method:


=head2 tcpsock:shutdown

B<syntax:> I<ok, err = tcpsock:shutdown("send")>

B<context:> I<content_by_luaE<42>>

Shuts down the write part of the request socket, prevents all further writing to the client
and sends TCP FIN, while keeping the reading half open.

Currently only the C<"send"> direction is supported. Using any parameters other than "send" will return
an error.

If you called any output functions (like L<ngx.say|https://github.com/openresty/lua-nginx-module#ngxsay>)
before calling this method, consider use C<ngx.flush(true)> to make sure all busy buffers are complely
flushed before shutting down the socket. If any busy buffers were detected, this method will return C<nil>
will error message C<"socket busy writing">.

This feature is particularly useful for protocols that generates response before actually
finishes consuming all incoming data. Normally Kernel will send out RST to the client when
L<tcpsock:close|https://github.com/openresty/lua-nginx-module#tcpsockclose> is called without
emptying the receiving buffer first. Calling this method will allow you to keep reading from
the receiving buffer and prevents RST from being sent.

You can also use this method to simulate lingering close similar to that
L<provided by the ngx_http_core_module|https://nginx.org/en/docs/http/ngx_http_core_module.html#lingering_close>
for protocols that needs such behavior. Here is an example:


    local LINGERING_TIME = 30 -- 30 seconds
    local LINGERING_TIMEOUT = 5000 -- 5 seconds
    
    local ok, err = sock:shutdown("send")
    if not ok then
        ngx.log(ngx.ERR, "failed to shutdown: ", err)
        return
    end
    
    local deadline = ngx.time() + LINGERING_TIME
    
    sock:settimeouts(nil, nil, LINGERING_TIMEOUT)
    
    repeat
        local data, _, partial = sock:receive(1024)
    until (not data and not partial) or ngx.time() >= deadline




=over


=item *

L<ngx.print|https://github.com/openresty/lua-nginx-module#ngxprint>

=item *

L<ngx.say|https://github.com/openresty/lua-nginx-module#ngxsay>

=item *

L<ngx.log|https://github.com/openresty/lua-nginx-module#ngxlog>

=item *

L<ngx.flush|https://github.com/openresty/lua-nginx-module#ngxflush>

This call currently ignores the C<wait> argument and always wait for all the pending
output to be completely flushed out (to the system socket send buffers).

=item *

L<ngx.exit|https://github.com/openresty/lua-nginx-module#ngxexit>

=item *

L<ngx.eof|https://github.com/openresty/lua-nginx-module#ngxeof>

=item *

L<ngx.sleep|https://github.com/openresty/lua-nginx-module#ngxsleep>

=item *

L<ngx.escape_uri|https://github.com/openresty/lua-nginx-module#ngxescape_uri>

=item *

L<ngx.unescape_uri|https://github.com/openresty/lua-nginx-module#ngxunescape_uri>

=item *

L<ngx.encode_args|https://github.com/openresty/lua-nginx-module#ngxencode_args>

=item *

L<ngx.decode_args|https://github.com/openresty/lua-nginx-module#ngxdecode_args>

=item *

L<ngx.encode_base64|https://github.com/openresty/lua-nginx-module#ngxencode_base64>

=item *

L<ngx.decode_base64|https://github.com/openresty/lua-nginx-module#ngxdecode_base64>

=item *

L<ngx.crc32_short|https://github.com/openresty/lua-nginx-module#ngxcrc32_short>

=item *

L<ngx.crc32_long|https://github.com/openresty/lua-nginx-module#ngxcrc32_long>

=item *

L<ngx.hmac_sha1|https://github.com/openresty/lua-nginx-module#ngxhmac_sha1>

=item *

L<ngx.md5|https://github.com/openresty/lua-nginx-module#ngxmd5>

=item *

L<ngx.md5_bin|https://github.com/openresty/lua-nginx-module#ngxmd5_bin>

=item *

L<ngx.sha1_bin|https://github.com/openresty/lua-nginx-module#ngxsha1_bin>

=item *

L<ngx.quote_sql_str|https://github.com/openresty/lua-nginx-module#ngxquote_sql_str>

=item *

L<ngx.today|https://github.com/openresty/lua-nginx-module#ngxtoday>

=item *

L<ngx.time|https://github.com/openresty/lua-nginx-module#ngxtime>

=item *

L<ngx.now|https://github.com/openresty/lua-nginx-module#ngxnow>

=item *

L<ngx.update_time|https://github.com/openresty/lua-nginx-module#ngxupdate_time>

=item *

L<ngx.localtime|https://github.com/openresty/lua-nginx-module#ngxlocaltime>

=item *

L<ngx.utctime|https://github.com/openresty/lua-nginx-module#ngxutctime>

=item *

L<ngx.re.match|https://github.com/openresty/lua-nginx-module#ngxrematch>

=item *

L<ngx.re.find|https://github.com/openresty/lua-nginx-module#ngxrefind>

=item *

L<ngx.re.gmatch|https://github.com/openresty/lua-nginx-module#ngxregmatch>

=item *

L<ngx.re.sub|https://github.com/openresty/lua-nginx-module#ngxresub>

=item *

L<ngx.re.gsub|https://github.com/openresty/lua-nginx-module#ngxregsub>

=item *

L<ngx.shared.DICT|https://github.com/openresty/lua-nginx-module#ngxshareddict>

=item *

L<ngx.socket.tcp|https://github.com/openresty/lua-nginx-module#ngxsockettcp>

=item *

L<ngx.socket.udp|https://github.com/openresty/lua-nginx-module#ngxsocketudp>

=item *

L<ngx.socket.connect|https://github.com/openresty/lua-nginx-module#ngxsocketconnect>

=item *

L<ngx.get_phase|https://github.com/openresty/lua-nginx-module#ngxget_phase>

=item *

L<ngx.thread.spawn|https://github.com/openresty/lua-nginx-module#ngxthreadspawn>

=item *

L<ngx.thread.wait|https://github.com/openresty/lua-nginx-module#ngxthreadwait>

=item *

L<ngx.thread.kill|https://github.com/openresty/lua-nginx-module#ngxthreadkill>

=item *

L<ngx.on_abort|https://github.com/openresty/lua-nginx-module#ngxon_abort>

=item *

L<ngx.timer.at|https://github.com/openresty/lua-nginx-module#ngxtimerat>

=item *

L<ngx.timer.running_count|https://github.com/openresty/lua-nginx-module#ngxtimerrunning_count>

=item *

L<ngx.timer.pending_count|https://github.com/openresty/lua-nginx-module#ngxtimerpending_count>

=item *

L<ngx.config.debug|https://github.com/openresty/lua-nginx-module#ngxconfigdebug>

=item *

L<ngx.config.subsystem|https://github.com/openresty/lua-nginx-module#ngxconfigsubsystem>

Always takes the Lua string value C<"stream"> in this module.

=item *

L<ngx.config.prefix|https://github.com/openresty/lua-nginx-module#ngxconfigprefix>

=item *

L<ngx.config.nginx_version|https://github.com/openresty/lua-nginx-module#ngxconfignginx_version>

=item *

L<ngx.config.nginx_configure|https://github.com/openresty/lua-nginx-module#ngxconfignginx_configure>

=item *

L<ngx.config.ngx_lua_version|https://github.com/openresty/lua-nginx-module#ngxconfigngx_lua_version>

=item *

L<ngx.worker.exiting|https://github.com/openresty/lua-nginx-module#ngxworkerexiting>

=item *

L<ngx.worker.pid|https://github.com/openresty/lua-nginx-module#ngxworkerpid>

=item *

L<ngx.worker.count|https://github.com/openresty/lua-nginx-module#ngxworkercount>

=item *

L<ngx.worker.id|https://github.com/openresty/lua-nginx-module#ngxworkerid>

=item *

L<coroutine.create|https://github.com/openresty/lua-nginx-module#coroutinecreate>

=item *

L<coroutine.resume|https://github.com/openresty/lua-nginx-module#coroutineresume>

=item *

L<coroutine.yield|https://github.com/openresty/lua-nginx-module#coroutineyield>

=item *

L<coroutine.wrap|https://github.com/openresty/lua-nginx-module#coroutinewrap>

=item *

L<coroutine.running|https://github.com/openresty/lua-nginx-module#coroutinerunning>

=item *

L<coroutine.status|https://github.com/openresty/lua-nginx-module#coroutinestatus>


=back




=head1 TODO


=over


=item *

Add new directives C<access_by_lua_block> and C<access_by_lua_file>.

=item *

Add new directives C<ssl_certificate_by_lua_block> and C<ssl_certificate_by_lua_file>.

=item *

Add C<ngx.semaphore> API.

=item *

Add support for L<lua-resty-core|https://github.com/openresty/lua-resty-core>.

=item *

Add C<lua_postpone_output> to emulate the L<postpone_output|http://nginx.org/r/postpone_output> directive.


=back




=head1 Nginx Compatibility

The latest version of this module is compatible with the following versions of Nginx:


=over


=item *

1.13.x E<gt>= 1.13.6


=back

Nginx cores older than 1.13.6 (exclusive) are I<not> tested and may or may not work. Use at your own risk!




=head1 Installation

This module can be manually compiled into Nginx or OpenResty:


=over


=item 1.

Install LuaJIT 2.1 or Lua 5.1 (Lua 5.2+ are I<not> supported yet). LuaJIT can be downloaded from the L<the LuaJIT project website|http://luajit.org/download.html> and Lua 5.1, from the L<Lua project website|http://www.lua.org/>.  Some distribution package managers also distribute LuaJIT and/or Lua.

=item 2.

Download the latest version of ngx_stream_lua L<HERE|https://github.com/openresty/stream-lua-nginx-module/tags>.

=item 3.

Download the latest supported version of NGINX L<HERE|http://nginx.org/> (See L<Nginx Compatibility>) or the OpenResty bundle from L<HERE|https://openresty.org/>.


=back

Build the source of NGINX or OpenResty with this module, like below:


    wget 'http://nginx.org/download/nginx-1.13.6.tar.gz'
    tar -xzvf nginx-1.13.6.tar.gz
    cd nginx-1.13.6/
    
    # tell nginx's build system where to find LuaJIT 2.1:
    export LUAJIT_LIB=/path/to/luajit/lib
    export LUAJIT_INC=/path/to/luajit/include/luajit-2.1
    
    # or tell where to find Lua if using Lua instead:
    #export LUA_LIB=/path/to/lua/lib
    #export LUA_INC=/path/to/lua/include
    
    # Here we assume Nginx is to be installed under /opt/nginx/.
    ./configure --prefix=/opt/nginx \
            --with-ld-opt="-Wl,-rpath,/path/to/luajit-or-lua/lib" \
            --with-stream \
            --with-stream_ssl_module \
            --add-module=/path/to/stream-lua-nginx-module
    
    # Build and install
    make -j4
    make install

You may use C<--without-http> if you do not wish to use this module with the HTTP subsystem.
ngx_stream_lua will work perfectly fine without the presense of the HTTP subsystem.




=head1 Community




=head2 English Mailing List

The L<openresty-en|https://groups.google.com/group/openresty-en> mailing list is for English speakers.




=head2 Chinese Mailing List

The L<openresty|https://groups.google.com/group/openresty> mailing list is for Chinese speakers.




=head1 Code Repository

The code repository of this project is hosted on github at L<openrestyE<sol>stream-lua-nginx-module|https://github.com/openresty/stream-lua-nginx-module>.




=head1 Bugs and Patches

Please submit bug reports, wishlists, or patches by


=over


=item 1.

creating a ticket on the L<GitHub Issue Tracker|https://github.com/openresty/stream-lua-nginx-module/issues>,

=item 2.

or posting to the L<OpenResty community>.


=back




=head1 Acknowledgments


=over


=item *

We appreciate L<Mashape, Inc.|https://www.mashape.com/> for kindly sponsoring L<OpenResty Inc.|https://openresty.com/> to make
this module compatible with Nginx core 1.13.3. In addition, they sponsored the work on making code sharing between this module and
L<lua-nginx-module|https://github.com/openresty/lua-nginx-module>, as well as balancer_by_lua_I<, preread_by_lua_> and log_by_lua_* support possible.


=back


=head1 Copyright and License

This module is licensed under the BSD license.

Copyright (C) 2009-2018, by Yichun "agentzh" Zhang (章亦春) E<lt>agentzh@gmail.comE<gt>, OpenResty Inc.

Copyright (C) 2009-2016, by Xiaozhe Wang (chaoslawful) E<lt>chaoslawful@gmail.comE<gt>.

All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:


=over


=item *

Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.


=back


=over


=item *

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.


=back

THIS 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.




=head1 See Also


=over


=item *

L<ngx_http_lua_module|https://github.com/openresty/lua-nginx-module>

=item *

L<ngx_stream_echo_module|https://github.com/openresty/stream-echo-nginx-module>

=item *

L<OpenResty|https://openresty.org/>


=back



