mod_lua.xml revision fc57cc74ee4e73618f74a7a62ea6ac77546666da
fb51a6b789d85113d0976148685b0063c294220drbowen<!DOCTYPE modulesynopsis SYSTEM "/style/modulesynopsis.dtd">
b07b82e44c32825d6226ee801d2ed91555e593d1rbowen<?xml-stylesheet type="text/xsl" href="/style/manual.en.xsl"?>
77a0265761f1bec2aaa0b4116c644f8066e349e3rbowen<!-- $LastChangedRevision$ -->
b07b82e44c32825d6226ee801d2ed91555e593d1rbowen Licensed to the Apache Software Foundation (ASF) under one or more
b07b82e44c32825d6226ee801d2ed91555e593d1rbowen contributor license agreements. See the NOTICE file distributed with
b07b82e44c32825d6226ee801d2ed91555e593d1rbowen this work for additional information regarding copyright ownership.
b07b82e44c32825d6226ee801d2ed91555e593d1rbowen The ASF licenses this file to You under the Apache License, Version 2.0
b07b82e44c32825d6226ee801d2ed91555e593d1rbowen (the "License"); you may not use this file except in compliance with
b07b82e44c32825d6226ee801d2ed91555e593d1rbowen the License. You may obtain a copy of the License at
b07b82e44c32825d6226ee801d2ed91555e593d1rbowen Unless required by applicable law or agreed to in writing, software
b07b82e44c32825d6226ee801d2ed91555e593d1rbowen distributed under the License is distributed on an "AS IS" BASIS,
b07b82e44c32825d6226ee801d2ed91555e593d1rbowen WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
b07b82e44c32825d6226ee801d2ed91555e593d1rbowen See the License for the specific language governing permissions and
b07b82e44c32825d6226ee801d2ed91555e593d1rbowen limitations under the License.
4b2d52ed83bf31730c8b6bbe7c06d806dc3a0c4erbowen<description>Provides Lua hooks into various portions of the httpd
4b2d52ed83bf31730c8b6bbe7c06d806dc3a0c4erbowenrequest processing</description>
fb51a6b789d85113d0976148685b0063c294220drbowen<p>This module allows the server to be extended with scripts written in the
fb51a6b789d85113d0976148685b0063c294220drbowenLua programming language. The extension points (hooks) available with
fb51a6b789d85113d0976148685b0063c294220drbowen<module>mod_lua</module> include many of the hooks available to
fb51a6b789d85113d0976148685b0063c294220drbowennatively compiled Apache HTTP Server modules, such as mapping requests to
4b2d52ed83bf31730c8b6bbe7c06d806dc3a0c4erbowenfiles, generating dynamic responses, access control, authentication, and
fb51a6b789d85113d0976148685b0063c294220drbowenauthorization</p>
fb51a6b789d85113d0976148685b0063c294220drbowen<p>More information on the Lua programming language can be found at the
4b2d52ed83bf31730c8b6bbe7c06d806dc3a0c4erbowen<a href="http://www.lua.org/">the Lua website</a>.</p>
4b2d52ed83bf31730c8b6bbe7c06d806dc3a0c4erbowen<note><code>mod_lua</code> is still in experimental state.
4b2d52ed83bf31730c8b6bbe7c06d806dc3a0c4erbowenUntil it is declared stable, usage and behavior may change
fb51a6b789d85113d0976148685b0063c294220drbowenat any time.</note>
fb51a6b789d85113d0976148685b0063c294220drbowen<section id="basicconf"><title>Basic Configuration</title>
fb51a6b789d85113d0976148685b0063c294220drbowen<code>mod_lua</code> provides a handler named <code>lua-script</code>,
fb51a6b789d85113d0976148685b0063c294220drbowenwhich can be used with an <code>AddHandler</code> directive:</p>
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowenAddHandler lua-script .lua
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowenThis will cause <code>mod_lua</code> to handle requests for files
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowen<p>For more flexibility, see <directive>LuaMapHandler</directive>.
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowen<section id="writinghandlers"><title>Writing Handlers</title>
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowen<p> In the Apache HTTP Server API, the handler is a specific kind of hook
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowenresponsible for generating the response. Examples of modules that include a
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowenhandler are <module>mod_proxy</module>, <module>mod_cgi</module>,
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowen<p><code>mod_lua</code> always looks to invoke a Lua function for the handler, rather than
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowenjust evaluating a script body CGI style. A handler function looks
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowensomething like this:</p>
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowen-- example handler
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowenrequire "string"
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowen This is the default method name for Lua handlers, see the optional
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowen function-name in the LuaMapHandler directive to choose a different
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowen entry point.
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowenfunction handle(r)
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowen r:puts("Hello Lua World!\n")
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowen if r.method == 'GET' then
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowen for k, v in pairs( r:parseargs() ) do
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowen r:puts( string.format("%s: %s", k, v) )
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowen elseif r.method == 'POST' then
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowen for k, v in pairs( r:parsebody() ) do
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowen r:puts( string.format("%s: %s", k, v) )
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowen r:puts("unknown HTTP method " .. r.method)
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowenThis handler function just prints out the uri or form encoded
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowenarguments to a plaintext page.
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowenThis means (and in fact encourages) that you can have multiple
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowenhandlers (or hooks, or filters) in the same script.
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowen<section id="writinghooks"><title>Writing Hooks</title>
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowen<p>Hook functions are how modules (and Lua scripts) participate in the
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowenprocessing of requests. Each type of hook exposed by the server exists for
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowena specific purposes such as mapping requests to the filesystem,
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowenperforming access control, or setting mimetypes. General purpose hooks
e27eee5caa6c1bf3853c11253ae82303cff0e40brbowenthat simply run at handy times in the request lifecycle exist as well.</p>
fb51a6b789d85113d0976148685b0063c294220drbowen<p>Hook functions are passed the request object as their only argument.
6b4cd1f143d5d7244d2476d1e28456212faddb72rbowenThey can return any value, depending on the hook, but most commonly
fb51a6b789d85113d0976148685b0063c294220drbowenthey'll return OK, DONE, or DECLINED, which you can write in lua as
fb51a6b789d85113d0976148685b0063c294220drbowen<code>apache2.OK</code>, <code>apache2.DONE</code>, or
fb51a6b789d85113d0976148685b0063c294220drbowen<code>apache2.DECLINED</code>, or else an HTTP status code.</p>
fb51a6b789d85113d0976148685b0063c294220drbowen-- example hook that rewrites the URI to a filesystem path.
fb51a6b789d85113d0976148685b0063c294220drbowenrequire 'apache2'
fb51a6b789d85113d0976148685b0063c294220drbowenfunction translate_name(r)
fb51a6b789d85113d0976148685b0063c294220drbowen if r.uri == "/translate-name" then
fb51a6b789d85113d0976148685b0063c294220drbowen -- we don't care about this URL, give another module a chance
c994f52ac80f9664d2940e5ccd9e77466572013frbowen--[[ example hook that rewrites one URI to another URI. It returns a
fb51a6b789d85113d0976148685b0063c294220drbowen apache2.DECLINED to give other URL mappers a chance to work on the
c994f52ac80f9664d2940e5ccd9e77466572013frbowen substitution, including the core translate_name hook which maps based
fb51a6b789d85113d0976148685b0063c294220drbowen on the DocumentRoot.
fb51a6b789d85113d0976148685b0063c294220drbowen Note: It is currently undefined as to whether this runs before or after
fb51a6b789d85113d0976148685b0063c294220drbowenrequire 'apache2'
fb51a6b789d85113d0976148685b0063c294220drbowenfunction translate_name(r)
fb51a6b789d85113d0976148685b0063c294220drbowen if r.uri == "/translate-name" then
fb51a6b789d85113d0976148685b0063c294220drbowen<section id="datastructures"><title>Data Structures</title>
fb51a6b789d85113d0976148685b0063c294220drbowen <p>The request_rec is mapped in as a userdata. It has a metatable
fb51a6b789d85113d0976148685b0063c294220drbowen which lets you do useful things with it. For the most part it
fb51a6b789d85113d0976148685b0063c294220drbowen has the same fields as the request_rec struct (see httpd.h
c994f52ac80f9664d2940e5ccd9e77466572013frbowen until we get better docs here) many of which are writeable as
fb51a6b789d85113d0976148685b0063c294220drbowen well as readable. (The table fields' content can be changed, but the
c994f52ac80f9664d2940e5ccd9e77466572013frbowen fields themselves cannot be set to different tables.)</p>
fb51a6b789d85113d0976148685b0063c294220drbowen <p>The request_rec has (at least) the following methods:</p>
fb51a6b789d85113d0976148685b0063c294220drbowen r:addoutputfilter(name|function) -- add an output filter
fb51a6b789d85113d0976148685b0063c294220drbowen r:parseargs() -- returns a lua table containing the request's
fb51a6b789d85113d0976148685b0063c294220drbowen query string arguments
fb51a6b789d85113d0976148685b0063c294220drbowen r:parsebody() -- parse the request body as a POST and return
fb51a6b789d85113d0976148685b0063c294220drbowen a lua table
fb51a6b789d85113d0976148685b0063c294220drbowen r:puts("hello", " world", "!") -- print to response body
fb51a6b789d85113d0976148685b0063c294220drbowen r:write("a single string") -- print to response body
fb51a6b789d85113d0976148685b0063c294220drbowen<section id="logging"><title>Logging Functions</title>
6b4cd1f143d5d7244d2476d1e28456212faddb72rbowen -- examples of logging messages<br />
6b4cd1f143d5d7244d2476d1e28456212faddb72rbowen r:trace1("This is a trace log message") -- trace1 through trace8 can be used <br />
6b4cd1f143d5d7244d2476d1e28456212faddb72rbowen r:debug("This is a debug log message")<br />
6b4cd1f143d5d7244d2476d1e28456212faddb72rbowen r:info("This is an info log message")<br />
6b4cd1f143d5d7244d2476d1e28456212faddb72rbowen r:notice("This is an notice log message")<br />
6b4cd1f143d5d7244d2476d1e28456212faddb72rbowen r:warn("This is an warn log message")<br />
6b4cd1f143d5d7244d2476d1e28456212faddb72rbowen r:err("This is an err log message")<br />
fb51a6b789d85113d0976148685b0063c294220drbowen r:alert("This is an alert log message")<br />
fb51a6b789d85113d0976148685b0063c294220drbowen r:crit("This is an crit log message")<br />
<description>Specify the base path for resolving relative paths for mod_lua directives</description>
LuaMapHandler /(\w+)/(/w+) /scripts/$1.lua handle_$2
conventions as lua. This just munges the package.path in the
conventions as lua. This just munges the package.cpath in the
until one of them returns apache2.OK. If your hook doesn't
apache2.DECLINED. If the request should stop processing, then
if r.uri == "/" then
return apache2.OK
return apache2.DECLINED
auth = r.headers_in['Authorization']
r.user = 'foo'
if r.user == nil then
r.err_headers_out['WWW-Authenticate'] = 'Basic realm="WallyWorld"'
elseif r.user == "foo" then
r:debug("authcheck: user='" .. r.user .. "'")
r.err_headers_out['WWW-Authenticate'] = 'Basic realm="WallyWorld"'
return apache2.OK