Mercurial > hg > nginx-site
diff xml/en/docs/stream/ngx_stream_js_module.xml @ 1840:15632fc2d548
Documented http and stream nginScript modules.
author | Yaroslav Zhuravlev <yar@nginx.com> |
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date | Fri, 18 Nov 2016 17:51:14 +0300 |
parents | |
children | f56626ce9c40 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/xml/en/docs/stream/ngx_stream_js_module.xml Fri Nov 18 17:51:14 2016 +0300 @@ -0,0 +1,320 @@ +<?xml version="1.0"?> + +<!-- + Copyright (C) Nginx, Inc. + --> + +<!DOCTYPE module SYSTEM "../../../../dtd/module.dtd"> + +<module name="Module ngx_stream_js_module" + link="/en/docs/stream/ngx_stream_js_module.html" + lang="en" + rev="1"> + +<section id="summary"> + +<para> +The <literal>ngx_stream_js_module</literal> module is used to +implement handlers in JavaScript. +</para> + +<para> +This module is not built by default, it should be compiled with +nginx JavaScript module using the +<literal>--add_module</literal> configuration parameter: +<example> +./configure --add-module=<value>path-to-njs</value>/nginx +</example> +The <link url="http://hg.nginx.org/njs">repository</link> +with nginx JavaScript module can be cloned with the following command +(requires <link url="https://www.mercurial-scm.org">Mercurial</link> client): +<example> +hg clone http://hg.nginx.org/njs +</example> +This module can also be built as +<link doc="../ngx_core_module.xml" id="load_module">dynamic</link>: +<example> +./configure --add-dynamic_module=<value>path-to-njs</value>/nginx +</example> +</para> + +</section> + + +<section id="issues" name="Known Issues"> + +<para> +The module is experimental, caveat emptor applies. +</para> + +</section> + + +<section id="example" name="Example Configuration"> + +<para> +<example> +stream { + js_include stream.js; + + server { + listen 12345; + + js_preread qux; + + js_set $foo foo; + js_set $bar bar; + + return foo; + } + + server { + listen 12346; + + js_access xyz; + proxy_pass 127.0.0.1:8000; + js_filter baz; + } +} + +http { + server { + listen 8000; + location / { + return 200 $http_foo\n; + } + } +} +</example> +</para> + +<para> +The <path>stream.js</path> file: +<example> +var req = ''; +var matched = 0; +var line = ''; + +function qux(s) { + n = s.buffer.indexOf('\n'); + if (n == -1) { + return s.AGAIN; + } + + line = s.buffer.substr(0, n); +} + +function foo(s) { + return line; +} + +function bar(s) { + var v = s.variables; + s.log("hello from bar() handler!"); + return "foo-var" + v.remote_port + "; pid=" + v.pid; +} + +// The filter processes one buffer per call. +// The buffer is available in s.buffer both for +// reading and writing. Called for both directions. + +function baz(s) { + if (s.fromUpstream || matched) { + return; + } + + // Disable certain addresses. + + if (s.remoteAddress.match('^192.*')) { + return s.ERROR; + } + + // Read HTTP request line. + // Collect bytes in 'req' until request + // line is read. Clear current buffer to + // disable output. + + req = req + s.buffer; + s.buffer = ''; + + n = req.search('\n'); + + if (n != -1) { + // Inject a new HTTP header. + var rest = req.substr(n + 1); + req = req.substr(0, n + 1); + + addr = s.remoteAddress; + + s.log('req:' + req); + s.log('rest:' + rest); + + // Output the result and skip further + // processing. + + s.buffer = req + 'Foo: addr_' + addr + '\r\n' + rest; + matched = 1; + } +} + +function xyz(s) { + if (s.remoteAddress.match('^192.*')) { + return s.ABORT; + } +} +</example> +</para> + +</section> + + +<section id="directives" name="Directives"> + +<directive name="js_access"> +<syntax><value>function</value></syntax> +<default/> +<context>stream</context> +<context>server</context> + +<para> +Sets a JavaScript function which will be called at the +<link doc="stream_processing.xml" id="access_phase">access</link> phase. +</para> + +</directive> + + +<directive name="js_filter"> +<syntax><value>function</value></syntax> +<default/> +<context>stream</context> +<context>server</context> + +<para> +Sets a data filter. +</para> + +</directive> + + +<directive name="js_include"> +<syntax><value>file</value></syntax> +<default/> +<context>stream</context> +<context>server</context> + +<para> +Specifies a file that implements server and variable handlers in JavaScript. +</para> + +</directive> + + +<directive name="js_preread"> +<syntax><value>function</value></syntax> +<default/> +<context>stream</context> +<context>server</context> + +<para> +Sets a JavaScript function which will be called at the +<link doc="stream_processing.xml" id="preread_phase">preread</link> phase. +</para> + +</directive> + + +<directive name="js_set"> +<syntax> +<value>$variable</value> <value>function</value></syntax> +<default/> +<context>stream</context> +<context>server</context> + +<para> +Sets a JavaScript function for the specified variable. +</para> + +</directive> + +</section> + + +<section id="properties" name="Session Object Properties"> +<para> +Each stream JavaScript handler receives one argument, a stream session object. +</para> + +<para> +The session object has the following properties: + +<list type="tag"> + +<tag-name><literal>remoteAddress</literal></tag-name> +<tag-desc> +client address, read-only +</tag-desc> + +<tag-name><literal>eof</literal></tag-name> +<tag-desc> +a boolean read-only property, true if the current buffer is the last buffer +</tag-desc> + +<tag-name><literal>fromUpstream</literal></tag-name> +<tag-desc> +a boolean read-only property, +true if the current buffer is from the upstream server to the client +</tag-desc> + +<tag-name><literal>buffer</literal></tag-name> +<tag-desc> +the current buffer, writable +</tag-desc> + +<tag-name><literal>variables{}</literal></tag-name> +<tag-desc> +nginx variables object, read-only +</tag-desc> + +<tag-name><literal>OK</literal></tag-name> +<tag-desc> +the <literal>OK</literal> return code +</tag-desc> + +<tag-name><literal>DECLINED</literal></tag-name> +<tag-desc> +the <literal>DECLINED</literal> return code +</tag-desc> + +<tag-name><literal>AGAIN</literal></tag-name> +<tag-desc> +the <literal>AGAIN</literal> return code +</tag-desc> + +<tag-name><literal>ERROR</literal></tag-name> +<tag-desc> +the <literal>ERROR</literal> return code +</tag-desc> + +<tag-name><literal>ABORT</literal></tag-name> +<tag-desc> +the <literal>ABORT</literal> return code +</tag-desc> +</list> +</para> + +<para> +The session object has the following methods: + +<list type="tag"> + +<tag-name><literal>log(<value>string</value>)</literal></tag-name> +<tag-desc> +writes a sent <value>string</value> to the error log +</tag-desc> +</list> +</para> + +</section> + +</module>