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StrongLoop microgateway使用总结（三）
源码引入
github地址https://github.com/strongloop/microgateway
不使用manage管理工具
网关访问多个接口获取后台数据聚合问题
由于自带策略invoke只实现一个后台接口对应一个网关接口.这导致数据聚合无法实现
自定义策略, 思想: 网关请求多个接口,拿到数据整合再返回
invoke 主要实现方法, 拿到yaml文件中的属性 target-url 经过一系列的验证再发送http或者https请求
muti-invoke 实现方法: 修改 yaml 文件属性, 将 target-url 改为 object 类型, 在原本的invoke 策略下添加外循环, 依次请求接口, 由于是异步请求, 所以我们使用Promise来顺序执行, 以便我们确保所有接口的请求都是完成的, 如果报错,发送报错信息.
js代码如下 // Copyright IBM Corp. 2016. All Rights Reserved. // Node module: microgateway // US Government Users Restricted Rights - Use, duplication or disclosure // restricted by GSA ADP Schedule Contract with IBM Corp. 'use strict'; var _ = require('lodash'); var url = require('url'); var qs = require('qs'); var zlib = require('zlib'); var dsc = require('microgateway-datastore/client/index.js'); ////one-time effort: read the cipher table into memory //var cipherTable; //try { // //the mapping table of TLS to OpenSSL ciphersuites // cipherTable = require(__dirname + '/../../lib/cipher-suites.json'); //} //catch (err) { // logger.error('Warning! Cannot read the cipher table for invoke policy. %s', // err); // cipherTable = {}; //} /** * Do the real work of the invoke policy: read the property and decide the * parametersBuffer.concat, establish the connection after everything is ready. */ function _main(props, context, next, logger, writeDst, tlsProfile) { //the default settings and error object var readSrc; var options = []; // 存放url数组 var isSecured; // https控制变量 var verb; var useChunk = false; var timeout = 60; var compression = false; var error = { name: 'PropertyError' }; var data; var datas = [];// 最终数据存储 var dataSz = 0; var count = 0; // 请求计数器 // 状态数组，获取所有请求的状态 var Status = []; var promiseArr = []; if (typeof props['target-url'] === 'object') { for(var u in props['target-url']){ // 将参数中的url全部拿出 options.push(url.parse(props['target-url'][u])); } } //target-url // 循环遍历url数组，发送请求 for(var i=0; i<options.length; i++){ if (!options[i] || !options[i].hostname || !options[i].protocol || (options[i].protocol !== 'http:' && options[i].protocol !== 'https:')) { error.message = 'Invalid target-url: "' + props['target-url'][i] + '"'; next(error); return; } else if (options[i].protocol === 'https:') { if (!tlsProfile) { logger.warn('[test-target] no TLS profile for a HTTPS connection'); } isSecured = true; } if (logger.info()) { logger.info('[muti-invoke] url: %s', maskQueryStringInURL(options[i].href)); } //verb: default to request.verb verb = props.verb ? String(props.verb).toUpperCase() : (context.request ? context.request.verb.toUpperCase() : undefined); if (verb !== 'POST' && verb !== 'GET' && verb !== 'PUT' && verb !== 'DELETE' && verb !== 'OPTIONS' && verb !== 'HEAD' && verb !== 'PATCH') { error.message = 'Invalid verb: "' + props.verb + '"'; next(error); return; } else { options[i].method = verb; } logger.debug('[muti-invoke] verb: %s', verb); //http-version: 1.1 if (props['http-version'] && props['http-version'] !== '1.1') { error.message = 'Invalid http-version: "' + props['http-version'] + '"'; next(error); return; } //timeout: between 1 to 86400 seconds if (!isNaN(parseInt(props.timeout, 10))) { var tmp = parseInt(props.timeout, 10); if (tmp < 1) { timeout = 1; } else if (tmp > 86400) { timeout = 86400; } else { timeout = tmp; } } logger.debug('[muti-invoke] timeout: %s seconds', timeout); //authentication if (props.username && props.password) { options[i].auth = props.username + ':' + props.password; } //readSrc: decide where to read the data if (props.input) { if (typeof props.input === 'string') { var theIn = context.get(props.input); if (typeof theIn === 'object') { logger.info('[muti-invoke] will read data and headers from "%s"', props.input); readSrc = theIn; } } if (!readSrc) { logger.error('Cannot read data or headers from the input ' + 'property "%s"', props.input); error.message = 'Invalid input: "' + props.input + '"'; next(error); return; } } else { readSrc = context.message; } //clone the readSrc.headers, because some headers need to be excluded options[i].headers = _.clone(readSrc.headers); //The headers that should not be copied var excludes = [ 'host', 'connection', 'content-length', 'transfer-encoding' ]; //deal with the user-agent: default, custom, remove, nochange excludes.push('user-agent'); //test if the content-type is urlencoded var isFormUrlEncoded; for (var hn in options[i].headers) { var target = hn.toLowerCase(); if (target === 'content-type' && options[i].headers[hn] === 'application/x-www-form-urlencoded') { isFormUrlEncoded = true; } var index = excludes.indexOf(target); if (index >= 0) { // remove the header that shouldn't be sent delete options[i].headers[hn]; // remove the header already processed excludes.splice(index, 1); } //early exit if (excludes.length === 0 && isFormUrlEncoded) { break; } } //inject the *default* User-Agent options[i].headers['User-Agent'] = 'APIConnect/5.0 (MicroGateway)'; //prepare the data and dataSz data = (readSrc.body === undefined ? '' : readSrc.body); if (!Buffer.isBuffer(data) && typeof data !== 'string') { if (typeof data === 'object') { if (isFormUrlEncoded) { data = qs.stringify(data); } else { data = JSON.stringify(data); } } else { data = String(data); } } dataSz = data.length; //chunked-upload if (props['chunked-upload'] && props['chunked-upload'] !== 'false') { useChunk = true; } logger.debug('[muti-invoke] useChunk: %s', useChunk); //compression if (props.compression === true || props.compression === 'true') { compression = true; } logger.debug('[muti-invoke] compression: %s', compression); //Compress the data or not if (compression) { options[i].headers['Content-Encoding'] = 'gzip'; } //when compression is true, we can only use chunks if (!compression && !useChunk && verb !== 'GET' && verb !== 'HEAD' && verb !== 'OPTIONS') { options[i].headers['Content-Length'] = dataSz; logger.debug('[muti-invoke] content-length = %d', dataSz); } //sensitive data //logger.debug('[invoke] w/ headers: %j', options.headers, {}); //setup the HTTPs settings var http = isSecured ? require('https') : require('http'); if (isSecured) { options[i].agent = false; // do we really want to set this? no conn pooling options[i].rejectUnauthorized = false; if (tlsProfile) { //key options[i].key = tlsProfile['private-key']; //cert for (var c in tlsProfile.certs) { if (tlsProfile.certs[c]['cert-type'] === 'PUBLIC') { options[i].cert = tlsProfile.certs[c].cert; break; } } //ca list options[i].ca = []; for (var p in tlsProfile.certs) { if (tlsProfile.certs[p]['cert-type'] === 'CLIENT') { logger.debug('[muti-invoke] uses the ca.name: %s', tlsProfile.certs[p].name); options[i].ca.push(tlsProfile.certs[p].cert); } } if (options[i].ca.length > 0 || tlsProfile['mutual-auth']) { options[i].rejectUnauthorized = true; logger.debug('[muti-invoke] rejectUnauthorized = true'); } //secureProtocol if (tlsProfile.protocols && Array.isArray(tlsProfile.protocols)) { for (var j = 0; j < tlsProfile.protocols.length; j++) { switch (tlsProfile.protocols[j]) { case 'TLSv1': options[i].secureProtocol = 'TLSv1_method'; break; case 'TLSv11': options[i].secureProtocol = 'TLSv1_1_method'; break; case 'TLSv12': options[i].secureProtocol = 'TLSv1_2_method'; break; default: logger.warn('[muti-invoke] unsupported secure protocol: %s', tlsProfile.protocols[j]); break; } if (options[i].secureProtocol) { break; } } } //use default ciphers options[i].honorCipherOrder = true; options[i].ciphers = 'HIGH:MEDIUM:!aNULL:!eNULL:!RC4:@STRENGTH'; //var ciphers = []; //if (tlsProfile.ciphers && Array.isArray(tlsProfile.ciphers)) { // for (var k=0; k<tlsProfile.ciphers.length; k++) { // var cipher = cipherTable[tlsProfile.ciphers[k]]; // if (cipher) { // logger.debug("[invoke] using cipher: %s", cipher); // ciphers.push(cipher); // } // else // logger.warn("[invoke] unknown cipher: %s", tlsProfile.ciphers[k]); // } // options.ciphers = ciphers.join(':'); //} } } //write the request try { promiseArr.push(getData(http,options[i],writeDst,data,datas,logger,Status,compression,timeout)) } catch (err) { if(count == options.length && datas.length==0){ // 如果请求发送完毕并且数据不为空 error.name = 'ConnectionError'; error.message = err.toString(); next(error); return; } else if(count == options.length && datas.length != 0){ // 如果请求发送完毕出现错误但是数据取到一部分 next(); } else{ continue; // 否则继续请求数据 } } } // 依次执行 Promise.all(promiseArr) .then(function () { // 返回数据 writeDst.body = datas; //Let Express itself to decide the final transfer-encoding var discard = [ 'transfer-encoding' ]; for (var m in discard) { var tbd = discard[m]; for (var n in writeDst.headers) { if (n.toLowerCase() === tbd) { delete writeDst.headers[n]; break; } } } // 在最后一次的请求返回后再向用户返回数据 var flag = false; // 判断所有请求的状态中是否存在 2开头的状态码 for(var s=0; s<Status.length; s++){ if(/^2/.test(String(Status[s].code))){ flag = true; // 如果存在结束循环 writeDst.status = { code: Status[s].code, reason: Status[s].reason }; break; } } // 只要存在成功的请求，我们都返回成功 if (flag) { // 存在2xx，请求至少成功1次 logger.info('[muti-invoke] received a %d response', writeDst.status.code); next(); } else { logger.error('[muti-invoke] OperationError! Received a non-2xx response (code=%d)',response.statusCode); error.name = 'OperationError'; error.message = response.statusCode + ': ' + response.reasonPhrase; next(error); } }) } // 该方法返回一个promise 数组 function getData(http,options, writeDst, data, datas, logger, Status,compression,timeout){ return new Promise((resolve,reject) => { var request = http.request(options, function(response) { Status.push({ url: options.href, code: response.statusCode, reason: response.reasonPhrase }); writeDst.headers = {}; //note: there is no response.rawHeaders for node v0.10.43 var rhrs = response.rawHeaders || response.headers; for (var j = 0; j < rhrs.length; j += 2) { writeDst.headers[rhrs[j]] = rhrs[j + 1]; } var chunks = []; response.on('data', function(data) { chunks.push(data); }); response.on('end', function() { logger.info('[muti-invoke] done'); //Decide whether the body should be a Buffer or JSON object. //If the content-type says it is a JSON object, try to parse it. var tmp = Buffer.concat(chunks); var cEncode = response.headers['content-encoding']; //ex: gzip var cType = response.headers['content-type']; if (!cEncode) { if (cType === 'application/x-www-form-urlencoded') { tmp = qs.parse(tmp.toString()); } else if (cType && cType.toLowertimeOutCase().indexOf('json') !== -1) { try { tmp = JSON.parse(tmp); } catch (e) { logger.warn('Failed parse the body (%s) as JSON: %s. ' + 'Leave it as a Buffer object', cType, e); } } //TODO: parse XML and check SOAPError when applicable? } // 数据聚合 datas.push({ status:{ url: options.href, code: response.statusCode, statusCode: tmp.statusCode, }, data:tmp.msg }); resolve() }); }); request.setTimeout(timeout * 1000, function() { logger.error('[muti-invoke] The invoke policy is timeouted.'); error.name = 'ConnectionError'; error.message = 'The invoke policy is timeouted.'; request.abort(); reject(error); }); // setup the error callbanextck request.on('error', function(err) { logger.error('[muti-invoke] request failed: %s', err); error.name = 'ConnectionError'; error.message = err.toString(); reject(error); }); if (compression) { zlib.gzip(data, function(err, buffer) { if (err) { logger.error('[muti-invoke] cannot compress the data'); reject(err); request.abort(); } else { request.write(buffer); request.end(); } }); } else { request.write(data); request.end(); } }) } /** * The entry point of the invoke policy. * Read the TLS profile first and do the real work then. */ function invoke(props, context, flow) { var logger = flow.logger; //writeDst: first thing, decide where to write the response if (context.message === undefined) { context.message = {}; //In fact, this should never happen } var writeDst = context.message; //stop on error, default to the ConnectionError only var stopOnError = [ 'ConnectionError' ]; var isDone = false; function _next(v) { if (!isDone) { isDone = true; if (v) { if (v.name !== 'PropertyError' && stopOnError.indexOf(v.name) === -1) { //ignore the error. Will continue with the next policy logger.info('[muti-invoke] ignore the error "%s" and continue', v.name); if (v.name === 'ConnectionError') { writeDst.status = { code: 500, reason: 'URL Open error' }; } flow.proceed(); } else { //fail with the error if (v.name === 'ConnectionError') { v.status = { code: 500, reason: 'URL Open error' }; } flow.fail(v); } } else { flow.proceed(); } } } var error = { name: 'PropertyError' }; if (!props || typeof props !== 'object') { error.message = 'Invalid property object'; _next(error); return; } if (props.output) { if (typeof props.output === 'string') { logger.info('[muti-invoke] the output destination will be set to %s', props.output); var theOut = {}; context.set(props.output, theOut); writeDst = theOut; } else { logger.error('[muti-invoke] the output property "%s" is not valid.'); error.message = 'Invalid output: "' + props.output + '"'; _next(error); } } if (Array.isArray(props['stop-on-error'])) { stopOnError = props['stop-on-error']; } logger.debug('[muti-invoke] stop-on-error is set to', stopOnError); var snapshotId = context.get('config-snapshot-id'); var profile = props['tls-profile']; var tlsProfile; if (!profile || typeof profile !== 'string' || profile.length === 0) { _main(props, context, _next, logger, writeDst); } else { logger.debug('[muti-invoke] reading the TLS profile "%s"', profile); dsc.getTlsProfile(snapshotId, profile).then( function(result) { if (result !== undefined && Array.isArray(result) && result.length > 0) { tlsProfile = result[0]; } if (!tlsProfile) { logger.error('[muti-invoke] cannot find the TLS profile "%s"', profile); error.message = 'Cannot find the TLS profile "' + profile + '"'; _next(error); return; } else { _main(props, context, _next, logger, writeDst, tlsProfile); } }, function(e) { logger.error('[muti-invoke] error w/ retrieving TLS profile: %s', e); error.message = e.toString(); _next(error); }); } } module.exports = function(config) { return invoke; }; /* * return query string from url */ function maskQueryStringInURL(url) { url = url || ''; return url.replace(/\?.*?$/, ''); }启动网关,在 yaml 文件中的 target-url 赋值为 [“http://localhost:5001/1“, “http://localhost:5001/2“] 具体请自行设定
执行 curl http://locakhost:5000/sapmle/echo 返回一个数据数组