eureka-js-client

<!doctype html> <html lang="en"> <head> <title>Code coverage report for src/EurekaClient.js</title> <meta charset="utf-8" /> <link rel="stylesheet" href="../prettify.css" /> <link rel="stylesheet" href="../base.css" /> <meta name="viewport" content="width=device-width, initial-scale=1"> <style type='text/css'> .coverage-summary .sorter { background-image: url(../sort-arrow-sprite.png); } </style> </head> <body> <div class='wrapper'> <div class='pad1'> <h1> <a href="../index.html">all files</a> / <a href="index.html">src/</a> EurekaClient.js </h1> <div class='clearfix'> <div class='fl pad1y space-right2'> 94.79% Statements 364/384 </div> <div class='fl pad1y space-right2'> 89.47% Branches 221/247 </div> <div class='fl pad1y space-right2'> 93.06% Functions 67/72 </div> <div class='fl pad1y space-right2'> 95.1% Lines 272/286 </div> <div class='fl pad1y'> 7 statements, 1 function, 20 branches Ignored      </div> </div> </div> <div class='status-line high'></div> <pre><table class="coverage"> <tr><td class="line-count quiet">1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 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  25× 25× 25×               27×     27×       27× 1× 1×     1×         26×          </td><td class="text"><pre class="prettyprint lang-js">import request from 'request'; import fs from 'fs'; import yaml from 'js-yaml'; import { merge, findIndex } from 'lodash'; import { normalizeDelta, findInstance } from './deltaUtils'; import path from 'path'; import { series, waterfall } from 'async'; import { EventEmitter } from 'events';   import AwsMetadata from './AwsMetadata'; import ConfigClusterResolver from './ConfigClusterResolver'; import DnsClusterResolver from './DnsClusterResolver'; import Logger from './Logger'; import defaultConfig from './defaultConfig';   function noop() {}   /* Eureka JS client This module handles registration with a Eureka server, as well as heartbeats for reporting instance health. */   function fileExists(file) { try { return fs.statSync(file); } catch (e) { return false; } }   function getYaml(file) { let yml = {}; if (!fileExists(file)) { return yml; // no configuration file } try { yml = yaml.safeLoad(fs.readFileSync(file, 'utf8')); } catch (e) { // configuration file exists but was malformed throw new Error(`Error loading YAML configuration file: ${file} ${e}`); } return yml; }   export default class Eureka extends EventEmitter {   constructor(config = {}) { super(); // Allow passing in a custom logger: this.logger = config.logger || new Logger();   this.logger.debug('initializing eureka client');   // Load up the current working directory and the environment: const cwd = config.cwd || process.cwd(); const env = process.env.EUREKA_ENV || process.env.NODE_ENV || 'development';   const filename = config.filename || 'eureka-client';   // Load in the configuration files: const defaultYml = getYaml(path.join(cwd, `${filename}.yml`)); const envYml = getYaml(path.join(cwd, `${filename}-${env}.yml`));   // apply config overrides in appropriate order this.config = merge({}, defaultConfig, defaultYml, envYml, config);   // Validate the provided the values we need: this.validateConfig(this.config);   this.requestMiddleware = this.config.requestMiddleware;   this.hasFullRegistry = false;   if (this.amazonDataCenter) { this.metadataClient = new AwsMetadata({ logger: this.logger, }); }   if (this.config.eureka.useDns) { this.clusterResolver = new DnsClusterResolver(this.config, this.logger); } else { this.clusterResolver = new ConfigClusterResolver(this.config, this.logger); }   this.cache = { app: {}, vip: {}, }; }   /* Helper method to get the instance ID. If the datacenter is AWS, this will be the instance-id in the metadata. Else, it's the hostName. */ get instanceId() { if (this.config.instance.instanceId) { return this.config.instance.instanceId; } else if (this.amazonDataCenter) { return this.config.instance.dataCenterInfo.metadata['instance-id']; } return this.config.instance.hostName; }   /* Helper method to determine if this is an AWS datacenter. */ get amazonDataCenter() { const { dataCenterInfo } = this.config.instance; return ( dataCenterInfo && dataCenterInfo.name && dataCenterInfo.name.toLowerCase() === 'amazon' ); }   /* Registers instance with Eureka, begins heartbeats, and fetches registry. */ start(callback = noop) { series([ done => { if (Ithis.metadataClient && this.config.eureka.fetchMetadata) { return this.addInstanceMetadata(done); } done(); }, done => { if (this.config.eureka.registerWithEureka) { return this.register(done); } done(); }, done => { if (this.config.eureka.registerWithEureka) { this.startHeartbeats(); } if (Ethis.config.eureka.fetchRegistry) { this.startRegistryFetches(); if (Ithis.config.eureka.waitForRegistry) { const waitForRegistryUpdate = (cb) => { this.fetchRegistry(() => { const instances = this.getInstancesByVipAddress(this.config.instance.vipAddress); if (instances.length === 0) setTimeout(() => waitForRegistryUpdate(cb), 2000); else cb(); }); }; return waitForRegistryUpdate(done); } this.fetchRegistry(done); } else { done(); } }, ], (err, ...rest) => { if (err) { this.logger.warn('Error starting the Eureka Client', err); } else { this.emit('started'); } callback(err, ...rest); }); }   /* De-registers instance with Eureka, stops heartbeats / registry fetches. */ stop(callback = noop) { clearInterval(this.registryFetch); if (this.config.eureka.registerWithEureka) { clearInterval(this.heartbeat); this.deregister(callback); } else { callback(); } }   /* Validates client configuration. */ validateConfig(config) { function validate(namespace, key) { if (!config[namespace][key]) { throw new TypeError(`Missing "${namespace}.${key}" config value.`); } }   if (config.eureka.registerWithEureka) { validate('instance', 'app'); validate('instance', 'vipAddress'); validate('instance', 'port'); validate('instance', 'dataCenterInfo'); }   if (typeof config.requestMiddleware !== 'function') { throw new TypeError('requestMiddleware must be a function'); } }   /* Registers with the Eureka server and initializes heartbeats on registration success. */ register(callback = noop) { this.config.instance.status = 'UP'; const connectionTimeout = setTimeout(() => { this.logger.warn('It looks like it\'s taking a while to register with ' + 'Eureka. This usually means there is an issue connecting to the host ' + 'specified. Start application with NODE_DEBUG=request for more logging.'); }, 10000); this.eurekaRequest({ method: 'POST', uri: this.config.instance.app, json: true, body: { instance: this.config.instance }, }, (error, response, body) => { clearTimeout(connectionTimeout); if (!error && response.statusCode === 204) { this.logger.info( 'registered with eureka: ', `${this.config.instance.app}/${this.instanceId}` ); this.emit('registered'); return callback(null); } else if (error) { this.logger.warn('Error registering with eureka client.', error); return callback(error); } return callback( new Error(`eureka registration FAILED: status: ${response.statusCode} body: ${body}`) ); }); }   /* De-registers with the Eureka server and stops heartbeats. */ deregister(callback = noop) { this.eurekaRequest({ method: 'DELETE', uri: `${this.config.instance.app}/${this.instanceId}`, }, (error, response, body) => { if (!error && response.statusCode === 200) { this.logger.info( `de-registered with eureka: ${this.config.instance.app}/${this.instanceId}` ); this.emit('deregistered'); return callback(null); } else if (error) { this.logger.warn('Error deregistering with eureka', error); return callback(error); } return callback( new Error(`eureka deregistration FAILED: status: ${response.statusCode} body: ${body}`) ); }); }   /* Sets up heartbeats on interval for the life of the application. Heartbeat interval by setting configuration property: eureka.heartbeatInterval */ startHeartbeats() { this.heartbeat = setInterval(() => { this.renew(); }, this.config.eureka.heartbeatInterval); }   renew() { this.eurekaRequest({ method: 'PUT', uri: `${this.config.instance.app}/${this.instanceId}`, }, (error, response, body) => { if (!error && response.statusCode === 200) { this.logger.debug('eureka heartbeat success'); this.emit('heartbeat'); } else Eif (!error && response.statusCode === 404) { this.logger.warn('eureka heartbeat FAILED, Re-registering app'); this.register(); } else { if (error) { this.logger.error('An error in the request occured.', error); } this.logger.warn( 'eureka heartbeat FAILED, will retry.' + `statusCode: ${response ? response.statusCode : 'unknown'}` + `body: ${body} ${error | ''} ` ); } }); }   /* Sets up registry fetches on interval for the life of the application. Registry fetch interval setting configuration property: eureka.registryFetchInterval */ startRegistryFetches() { this.registryFetch = setInterval(() => { this.fetchRegistry(err => { if (err) this.logger.warn('Error fetching registry', err); }); }, this.config.eureka.registryFetchInterval); }   /* Retrieves a list of instances from Eureka server given an appId */ getInstancesByAppId(appId) { if (!appId) { throw new RangeError('Unable to query instances with no appId'); } const instances = this.cache.app[appId.toUpperCase()] || []; if (instances.length === 0) { this.logger.warn(`Unable to retrieve instances for appId: ${appId}`); } return instances; }   /* Retrieves a list of instances from Eureka server given a vipAddress */ getInstancesByVipAddress(vipAddress) { if (!vipAddress) { throw new RangeError('Unable to query instances with no vipAddress'); } const instances = this.cache.vip[vipAddress] || []; if (instances.length === 0) { this.logger.warn(`Unable to retrieves instances for vipAddress: ${vipAddress}`); } return instances; }   /* Orchestrates fetching registry */ fetchRegistry(callback = noop) { if (this.config.shouldUseDelta && this.hasFullRegistry) { this.fetchDelta(callback); } else { this.fetchFullRegistry(callback); } }   /* Retrieves all applications registered with the Eureka server */ fetchFullRegistry(callback = noop) { this.eurekaRequest({ uri: '', headers: { Accept: 'application/json', }, }, (error, response, body) => { if (!error && response.statusCode === 200) { this.logger.debug('retrieved full registry successfully'); try { this.transformRegistry(JSON.parse(body)); } catch (ex) { return callback(ex); } this.emit('registryUpdated'); this.hasFullRegistry = true; return callback(null); } else if (error) { this.logger.warn('Error fetching registry', error); return callback(error); } callback(new Error('Unable to retrieve full registry from Eureka server')); }); }   /* Retrieves all applications registered with the Eureka server */ fetchDelta(callback = noop) { this.eurekaRequest({ uri: 'delta', headers: { Accept: 'application/json', }, }, (error, response, body) => { if (!error && response.statusCode === 200) { this.logger.debug('retrieved delta successfully'); let applications; try { const jsonBody = JSON.parse(body); applications = jsonBody.applications.application; this.handleDelta(this.cache, applications); return callback(null); } catch (ex) { return callback(ex); } } else if (error) { this.logger.warn('Error fetching delta registry', error); return callback(error); } callback(new Error('Unable to retrieve delta registry from Eureka server')); }); } /* Transforms the given registry and caches the registry locally */ transformRegistry(registry) { if (!registry) { this.logger.warn('Unable to transform empty registry'); } else { if (!registry.applications.application) { return; } const newCache = { app: {}, vip: {} }; if (Array.isArray(registry.applications.application)) { registry.applications.application.forEach((app) => { this.transformApp(app, newCache); }); } else { this.transformApp(registry.applications.application, newCache); } this.cache = newCache; } }   /* Transforms the given application and places in client cache. If an application has a single instance, the instance is placed into the cache as an array of one */ transformApp(app, cache) { if (app.instance.length) { app.instance .filter(this.validateInstance.bind(this)) .forEach((inst) => this.addInstance(cache, inst)); } else Eif (this.validateInstance(app.instance)) { this.addInstance(cache, app.instance); } }   /* Returns true if instance filtering is disabled, or if the instance is UP */ validateInstance(instance) { return (!this.config.eureka.filterUpIns