Mercurial > hg > nginx-site
view xml/en/docs/njs/njs_api.xml @ 2182:7865ca0da0ab
Merged HTTP request,response, and reply in njs.
author | Yaroslav Zhuravlev <yar@nginx.com> |
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date | Tue, 19 Jun 2018 15:43:42 +0300 |
parents | cb431c861670 |
children | 97526b8346f4 |
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<?xml version="1.0"?> <!-- Copyright (C) Nginx, Inc. --> <!DOCTYPE article SYSTEM "../../../../dtd/article.dtd"> <article name="njs API" link="/en/docs/njs/njs_api.html" lang="en" rev="2"> <section id="summary"> <para> <link doc="../njs_about.xml">njs</link> provides objects, methods and properties for extending nginx functionality. </para> </section> <section id="core" name="Core"> <section id="core_json" name="JSON"> <para> The <literal>JSON</literal> object (ES 5.1) provides functions to convert njs values to and from JSON format. <list type="tag"> <tag-name><literal>JSON.parse(<value>string</value>[, <value>reviver</value>])</literal></tag-name> <tag-desc> Converts a <literal>string</literal> that represents JSON data into an njs object (<literal>{...}</literal>) or array (<literal>[...]</literal>). The optional <literal>reviver</literal> parameter is a function (key, value) that will be called for each (key,value) pair and can transform the value. </tag-desc> <tag-name><literal>JSON.stringify(<value>value</value>[, <value>replacer</value>] [, <value>space</value>])</literal></tag-name> <tag-desc> Converts an njs object back to JSON. The obligatory <literal>value</literal> parameter is generally a JSON <literal>object</literal> or <literal>array</literal> that will be converted. If the value has a <literal>toJSON()</literal> method, it defines how the object will be serialized. The optional <literal>replacer</literal> parameter is a <literal>function</literal> or <literal>array</literal> that transforms results. The optional <literal>space</literal> parameter is a <literal>string</literal> or <literal>number</literal>. If it is a <literal>number</literal>, it indicates the number of white spaces placed before a result (no more than 10). If it is a <literal>string</literal>, it is used as a white space (or first 10 characters of it). If omitted or is <literal>null</literal>, no white space is used. </tag-desc> </list> </para> <para> <example> >> var json = JSON.parse('{"a":1, "b":true}') >> json.a 1 >> JSON.stringify(json) {"a":1,"b":true} >> JSON.stringify(json, undefined, 1) { "a": 1, "b": true } >> JSON.stringify({ x: [10, undefined, function(){}] }) {"x":[10,null,null]} >> JSON.stringify({"a":1, "toJSON": function() {return "xxx"}}) "xxx" # Example with function replacer >> function replacer(key, value) {return (typeof value === 'string') ? undefined : value} >>JSON.stringify({a:1, b:"b", c:true}, replacer) {"a":1,"c":true} </example> </para> </section> <section id="crypto" name="Crypto"> <para> The Crypto module provides cryptographic functionality support. The Crypto module object is returned by <literal>require('crypto')</literal>. </para> <para> <list type="tag"> <tag-name><literal>crypto.createHash(<value>algorithm</value>)</literal></tag-name> <tag-desc> Creates and returns a <link id="crypto_hash">Hash</link> object that can be used to generate hash digests using the given <value>algorithm</value>. The algorighm can be <literal>md5</literal>, <literal>sha1</literal>, and <literal>sha256</literal>. </tag-desc> <tag-name><literal>crypto.createHmac(<value>algorithm</value>, <value>secret key</value>)</literal></tag-name> <tag-desc> Creates and returns an <link id="crypto_hmac">HMAC</link> object that uses the given <value>algorithm</value> and <value>secret key</value>. The algorighm can be <literal>md5</literal>, <literal>sha1</literal>, and <literal>sha256</literal>. </tag-desc> </list> </para> <section id="crypto_hash" name="Hash"> <para> <list type="tag"> <tag-name><literal>hash.update(<value>data</value>)</literal></tag-name> <tag-desc> Updates the hash content with the given <value>data</value>. </tag-desc> <tag-name><literal>hash.digest([<value>encoding</value>])</literal></tag-name> <tag-desc> Calculates the digest of all of the data passed using <literal>hash.update()</literal>. The encoding can be <literal>hex</literal>, <literal>base64</literal>, and <literal>base64url</literal>. If encoding is not provided, a byte string is returned. </tag-desc> </list> </para> <para> <example> >> var cr = require('crypto') undefined >> cr.createHash('sha1').update('A').update('B').digest('base64url') BtlFlCqiamG-GMPiK_GbvKjdK10 </example> </para> </section> <section id="crypto_hmac" name="HMAC"> <para> <list type="tag"> <tag-name><literal>hmac.update(<value>data</value>)</literal></tag-name> <tag-desc> Updates the HMAC content with the given <value>data</value>. </tag-desc> <tag-name><literal>hmac.digest([<value>encoding</value>])</literal></tag-name> <tag-desc> Calculates the HMAC digest of all of the data passed using <literal>hmac.update()</literal>. The encoding can be <literal>hex</literal>, <literal>base64</literal>, and <literal>base64url</literal>. If encoding is not provided, a byte string is returned. </tag-desc> </list> </para> <para> <example> >> var cr = require('crypto') undefined >> cr.createHmac('sha1', 'secret.key').update('AB').digest('base64url') Oglm93xn23_MkiaEq_e9u8zk374 </example> </para> </section> </section> </section> <section id="http" name="HTTP"> <section id="http_request" name="Request"> <para> The <literal>HTTP</literal> object is available only in the <link doc="../http/ngx_http_js_module.xml">ngx_http_js_module</link> module. </para> <para> <list type="tag"> <tag-name><literal>r.args{}</literal></tag-name> <tag-desc> request arguments object, read-only </tag-desc> <tag-name><literal>r.error(<value>string</value>)</literal></tag-name> <tag-desc> writes a <literal>string</literal> to the error log on the <literal>error</literal> level of logging </tag-desc> <tag-name><literal>r.finish()</literal></tag-name> <tag-desc> finishes sending a response to the client </tag-desc> <tag-name><literal>r.headersIn{}</literal></tag-name> <tag-desc> incoming headers object, read-only. <para> For example, the <literal>Header-Name</literal> header can be accessed with the syntax <literal>headers['Header-Name']</literal> or <literal>headers.Header_name</literal> </para> </tag-desc> <tag-name><literal>r.headersOut{}</literal></tag-name> <tag-desc> outgoing headers object, writable. <para> For example, the <literal>Header-Name</literal> header can be accessed with the syntax <literal>headers['Header-Name']</literal> or <literal>headers.Header_name</literal> </para> </tag-desc> <tag-name><literal>r.httpVersion</literal></tag-name> <tag-desc> HTTP version, read-only </tag-desc> <tag-name><literal>r.log(<value>string</value>)</literal></tag-name> <tag-desc> writes a <literal>string</literal> to the error log on the <literal>info</literal> level of logging </tag-desc> <tag-name><literal>r.method</literal></tag-name> <tag-desc> HTTP method, read-only </tag-desc> <tag-name><literal>r.parent</literal></tag-name> <tag-desc> references the parent request object </tag-desc> <tag-name><literal>r.remoteAddress</literal></tag-name> <tag-desc> client address, read-only </tag-desc> <tag-name><literal>r.requestBody</literal></tag-name> <tag-desc> holds the request body, read-only </tag-desc> <tag-name><literal>r.responseBody</literal></tag-name> <tag-desc> holds the <link id="subrequest">subrequest</link> response body, read-only </tag-desc> <tag-name><literal>r.return(status[, string])</literal></tag-name> <tag-desc> sends the entire response with the specified <literal>status</literal> to the client <para> It is possible to specify either a redirect URL (for codes 301, 302, 303, 307, and 308) or the response body text (for other codes) as the second argument </para> </tag-desc> <tag-name><literal>r.send(<value>string</value>)</literal></tag-name> <tag-desc> sends a part of the response body to the client </tag-desc> <tag-name><literal>r.sendHeader()</literal></tag-name> <tag-desc> sends the HTTP headers to the client </tag-desc> <tag-name><literal>r.status</literal></tag-name> <tag-desc> status, writable </tag-desc> <tag-name><literal>r.variables{}</literal></tag-name> <tag-desc> nginx variables object, read-only </tag-desc> <tag-name><literal>r.warn(<value>string</value>)</literal></tag-name> <tag-desc> writes a <literal>string</literal> to the error log on the <literal>warning</literal> level of logging </tag-desc> <tag-name><literal>r.uri</literal></tag-name> <tag-desc> current URI, read-only </tag-desc> <tag-name id="subrequest"><literal>r.subrequest(<value>uri</value>[, <value>options</value>[, <value>callback</value>]])</literal></tag-name> <tag-desc> creates a subrequest with the given <literal>uri</literal> and <literal>options</literal>, and installs an optional completion <literal>callback</literal>. <para> If <literal>options</literal> is a string, then it holds the subrequest arguments string. Otherwise, <literal>options</literal> is expected to be an object with the following keys: <list type="tag"> <tag-name><literal>args</literal></tag-name> <tag-desc> arguments string </tag-desc> <tag-name><literal>body</literal></tag-name> <tag-desc> request body </tag-desc> <tag-name><literal>method</literal></tag-name> <tag-desc> HTTP method </tag-desc> </list> </para> <para> The completion <literal>callback</literal> receives a subrequest response object with methods and properties identical to the parent request object. </para> </tag-desc> </list> </para> </section> </section> <section id="stream" name="Stream"> <para> The <literal>stream</literal> object is available only in the <link doc="../stream/ngx_stream_js_module.xml">ngx_stream_js_module</link> module. </para> <section id="stream_session" name="Session"> <para> <list type="tag"> <tag-name><literal>s.remoteAddress</literal></tag-name> <tag-desc> client address, read-only </tag-desc> <tag-name><literal>s.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>s.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>s.buffer</literal></tag-name> <tag-desc> the current buffer, writable </tag-desc> <tag-name><literal>s.variables{}</literal></tag-name> <tag-desc> nginx variables object, read-only </tag-desc> <tag-name><literal>s.OK</literal></tag-name> <tag-desc> the <literal>OK</literal> return code </tag-desc> <tag-name><literal>s.DECLINED</literal></tag-name> <tag-desc> the <literal>DECLINED</literal> return code </tag-desc> <tag-name><literal>s.AGAIN</literal></tag-name> <tag-desc> the <literal>AGAIN</literal> return code </tag-desc> <tag-name><literal>s.ERROR</literal></tag-name> <tag-desc> the <literal>ERROR</literal> return code </tag-desc> <tag-name><literal>s.ABORT</literal></tag-name> <tag-desc> the <literal>ABORT</literal> return code </tag-desc> <tag-name><literal>s.log(<value>string</value>)</literal></tag-name> <tag-desc> writes a sent <value>string</value> to the error log on the <literal>info</literal> level of logging </tag-desc> <tag-name><literal>s.warn(<value>string</value>)</literal></tag-name> <tag-desc> writes a sent <literal>string</literal> to the error log on the <literal>warning</literal> level of logging </tag-desc> <tag-name><literal>s.error(<value>string</value>)</literal></tag-name> <tag-desc> writes a sent <literal>string</literal> to the error log on the <literal>error</literal> level of logging </tag-desc> </list> </para> </section> </section> <section id="example" name="Examples"> <section id="example_urldecode" name="URL Decoding"> <para> <example> js_include urldecode.js; js_set $decoded_foo decoded_foo; </example> </para> <para> The <path>urldecode.js</path> file: <example> function decoded_foo(r) { return decodeURIComponent(r.args.foo); } </example> </para> </section> <section id="example_urlencode" name="URL Encoding"> <para> <example> js_include urlencode.js; js_set $encoded_foo encoded_foo; ... location / { proxy_pass http://example.com?foo=$encoded_foo; } </example> </para> <para> The <path>urlencode.js</path> file: <example> function encoded_foo(r) { return encodeURIComponent('foo & bar?'); } </example> </para> </section> <section id="example_fast_response" name="Returning Fastest Response from Proxy"> <para> <example> js_include fastresponse.js; location /start { js_content content; } location /foo { proxy_pass http://backend1; } location /bar { proxy_pass http://backend2; } </example> </para> <para> The <path>fastresponse.js</path> file: <example> function content(r) { var n = 0; function done(res) { if (n++ == 0) { r.return(res.status, res.responseBody); } } r.subrequest('/foo', r.variables.args, done); r.subrequest('/bar', r.variables.args, done); } </example> </para> </section> <section id="example_jwt" name="Creating HS JWT"> <para> <example> js_include hs_jwt.js; js_set $jwt jwt; </example> </para> <para> The <path>hs_jwt.js</path> file: <example> function create_hs256_jwt(claims, key, valid) { var header = { "typ" : "JWT", "alg" : "HS256", "exp" : Date.now() + valid }; var s = JSON.stringify(header).toBytes().toString('base64url') + '.' + JSON.stringify(claims).toBytes().toString('base64url'); var h = require('crypto').createHmac('sha256', key); return s + '.' + h.update(s).digest().toString('base64url'); } function jwt(r) { var claims = { "iss" : "nginx", "sub" : "alice", "foo" : 123, "bar" : "qq", "zyx" : false }; return create_hs256_jwt(claims, 'foo', 600); } </example> </para> </section> <section id="example_subrequest" name="Accessing API from a Subrequest"> <para> <example> js_include subrequest.js; keyval_zone zone=foo:10m; ... location /keyval { js_content set_keyval; } location /version { js_content version; } location /api { api write=on; } </example> </para> <para> The <path>subrequest.js</path> file: <example> function set_keyval(r) { r.subrequest('/api/3/http/keyvals/foo', { method: 'POST', body: JSON.stringify({ foo: 789, bar: "ss dd 00" })}, function(res) { if (res.status >= 300) { r.return(res.status, res.responseBody); return; } r.return(500); }); } function version(r) { r.subrequest('/api/3/nginx', { method: 'GET' }, function(res) { if (res.status != 200) { r.return(res.status); return; } var json = JSON.parse(res.responseBody); r.return(200, json.version); }); } </example> </para> </section> <section id="example_secure_link" name="Creating secure_link Hash"> <para> <example> js_include hash.js; js_set $new_foo create_secure_link; ... location / { secure_link $cookie_foo; secure_link_md5 "$uri mykey"; ... } location @login { add_header Set-Cookie "foo=$new_foo; Max-Age=60"; return 302 /; } </example> </para> <para> The <path>hash.js</path> file: <example> function create_secure_link(r) { return require('crypto').createHash('md5') .update(r.uri).update(" mykey") .digest('base64url'); } </example> </para> </section> </section> </article>