Add hostname CLI flag and option for CriConnection (#2728)

* fixes #2727
hostname expressed as second parameter to avoid breaking existing
implementations

lighthouse-cli/cli-flags.ts

@@ -14,7 +14,7 @@ import {GetValidOutputOptions, OutputMode} from './printer';
 export interface Flags {
   port: number, chromeFlags: string, output: any, outputPath: string, interactive: boolean,
       saveArtifacts: boolean, saveAssets: boolean, view: boolean, maxWaitForLoad: number,
-      logLevel: string
+      logLevel: string, hostname: string
 }
 
 export function getFlags(manualArgv?: string) {
@@ -54,7 +54,7 @@ export function getFlags(manualArgv?: string) {
           [
             'save-assets', 'save-artifacts', 'list-all-audits', 'list-trace-categories',
             'additional-trace-categories', 'config-path', 'chrome-flags', 'perf', 'port',
-            'max-wait-for-load'
+            'hostname', 'max-wait-for-load'
           ],
           'Configuration:')
       .describe({
@@ -77,6 +77,7 @@ export function getFlags(manualArgv?: string) {
             CHROME_PATH: Explicit path of intended Chrome binary. If set must point to an executable of a build of Chromium version 54.0 or later. By default, any detected Chrome Canary or Chrome (stable) will be launched.
             `,
         'perf': 'Use a performance-test-only configuration',
+        'hostname': 'The hostname to use for the debugging protocol.',
         'port': 'The port to use for the debugging protocol. Use 0 for a random port',
         'max-wait-for-load':
             'The timeout (in milliseconds) to wait before the page is considered done loading and the run should continue. WARNING: Very high values can lead to large traces and instability',
@@ -107,6 +108,7 @@ Example: --output-path=./lighthouse-results.html`,
       .default('disable-cpu-throttling', false)
       .default('output', GetValidOutputOptions()[OutputMode.domhtml])
       .default('port', 0)
+      .default('hostname', 'localhost')
       .default('max-wait-for-load', Driver.MAX_WAIT_FOR_FULLY_LOADED)
       .check((argv: {listAllAudits?: boolean, listTraceCategories?: boolean, _: Array<any>}) => {
         // Make sure lighthouse has been passed a url, or at least one of --list-all-audits

lighthouse-core/gather/connections/cri.js

@@ -10,19 +10,20 @@ const WebSocket = require('ws');
 const http = require('http');
 const log = require('lighthouse-logger');
 
-const hostname = 'localhost';
+const DEFAULT_HOSTNAME = 'localhost';
 const CONNECT_TIMEOUT = 10000;
 const DEFAULT_PORT = 9222;
 
 class CriConnection extends Connection {
   /**
    * @param {number=} port Optional port number. Defaults to 9222;
+   * @param {string=} hostname Optional hostname. Defaults to localhost.
    * @constructor
    */
-  constructor(port) {
+  constructor(port = DEFAULT_PORT, hostname = DEFAULT_HOSTNAME) {
     super();
-
-    this.port = port || DEFAULT_PORT;
+    this.port = port;
+    this.hostname = hostname;
   }
 
   /**
@@ -77,7 +78,7 @@ class CriConnection extends Connection {
   _runJsonCommand(command) {
     return new Promise((resolve, reject) => {
       const request = http.get({
-        hostname: hostname,
+        hostname: this.hostname,
         port: this.port,
         path: '/json/' + command
       }, response => {

lighthouse-core/index.js

@@ -35,7 +35,7 @@ module.exports = function(url, flags = {}, configJSON) {
     // Use ConfigParser to generate a valid config file
     const config = new Config(configJSON, flags.configPath);
 
-    const connection = new ChromeProtocol(flags.port);
+    const connection = new ChromeProtocol(flags.port, flags.hostname);
 
     // kick off a lighthouse run
     return Runner.run(connection, {url, flags, config})

readme.md

@@ -63,6 +63,7 @@ Configuration:
                                                                                                                                        [default: ""]
   --perf                         Use a performance-test-only configuration                                                                 [boolean]
   --port                         The port to use for the debugging protocol. Use 0 for a random port                                 [default: 9222]
+  --hostname                     The hostname to use for the debugging protocol.                                                [default: localhost]
   --max-wait-for-load            The timeout (in milliseconds) to wait before the page is considered done loading and the run should continue.
                                  WARNING: Very high values can lead to large traces and instability                                 [default: 25000]