feat: added new option to change the server host

README.md

@@ -187,10 +187,11 @@ ignored.
 | Command-line flag  | Environment variable      | Description                                                                                                                                                                                                      |
 | ------------------ | ------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
 | `--port`           | `PORT`                    | The port on which the Functions Framework listens for requests. Default: `8080`                                                                                                                                  |
+| `--host`           | `HOST`                    | The host on which the Functions Framework listens for requests. Default: `''` [Check node documentation for the default behavior](https://nodejs.org/api/net.html#serverlistenport-host-backlog-callback)                                                                                                                                     |
 | `--target`         | `FUNCTION_TARGET`         | The name of the exported function to be invoked in response to requests. Default: `function`                                                                                                                     |
 | `--signature-type` | `FUNCTION_SIGNATURE_TYPE` | The signature used when writing your function. Controls unmarshalling rules and determines which arguments are used to invoke your function. Default: `http`; accepted values: `http` or `event` or `cloudevent` |
 | `--source`         | `FUNCTION_SOURCE`         | The path to the directory of your function. Default: `cwd` (the current working directory)                                                                                                                       |
-| `--log-execution-id`| `LOG_EXECUTION_ID`        | Enables execution IDs in logs, either `true` or `false`. When not specified, default to disable. Requires Node.js 13.0.0 or later.                                                                                |
+| `--log-execution-id`| `LOG_EXECUTION_ID`        | Enables execution IDs in logs, either `true` or `false`. When not specified, default to disable. Requires Node.js 13.0.0 or later.                                                                              |
 
 You can set command-line flags in your `package.json` via the `start` script.
 For example:

src/main.ts

@@ -56,8 +56,14 @@ export const main = async () => {
     options.signatureType = signatureType;
     const server = getServer(userFunction!, options);
     const errorHandler = new ErrorHandler(server);
+    const {host, port} = options;
+
+    const serverOptions = {
+      port,
+      ...(host && {host}),
+    };
     server
-      .listen(options.port, () => {
+      .listen(serverOptions, () => {
         errorHandler.register();
         if (process.env.NODE_ENV !== 'production') {
           console.log('Serving function...');

src/options.ts

@@ -31,6 +31,10 @@ export interface FrameworkOptions {
    * The port on which this server listens to all HTTP requests.
    */
   port: string;
+  /**
+   * The host on which this server listens for all HTTP requests.
+   */
+  host: string;
   /**
    * The name of the function within user's node module to execute. If such a
    * function is not defined, then falls back to 'function' name.
@@ -92,6 +96,7 @@ class ConfigurableOption<T> {
 }
 
 const PortOption = new ConfigurableOption('port', 'PORT', '8080');
+const HostOption = new ConfigurableOption('host', 'HOST', '');
 const FunctionTargetOption = new ConfigurableOption(
   'target',
   'FUNCTION_TARGET',
@@ -185,6 +190,7 @@ export const parseOptions = (
   });
   return {
     port: PortOption.parse(argv, envVars),
+    host: HostOption.parse(argv, envVars),
     target: FunctionTargetOption.parse(argv, envVars),
     sourceLocation: SourceLocationOption.parse(argv, envVars),
     signatureType: SignatureOption.parse(argv, envVars),

src/testing.ts

@@ -53,6 +53,7 @@ export const getTestServer = (functionName: string): Server => {
     enableExecutionId: false,
     timeoutMilliseconds: 0,
     port: '0',
+    host: '',
     target: '',
     sourceLocation: '',
     printHelp: false,

test/integration/legacy_event.ts

@@ -37,6 +37,7 @@ const testOptions = {
   enableExecutionId: false,
   timeoutMilliseconds: 0,
   port: '0',
+  host: '',
   target: '',
   sourceLocation: '',
   printHelp: false,

test/options.ts

@@ -54,6 +54,7 @@ describe('parseOptions', () => {
       envVars: {},
       expectedOptions: {
         port: '8080',
+        host: '',
         target: 'function',
         sourceLocation: resolve(''),
         signatureType: 'http',
@@ -75,10 +76,13 @@ describe('parseOptions', () => {
         '--source=/source',
         '--timeout',
         '6',
+        '--host',
+        '0.0.0.0',
       ],
       envVars: {},
       expectedOptions: {
         port: '1234',
+        host: '0.0.0.0',
         target: 'helloWorld',
         sourceLocation: resolve('/source'),
         signatureType: 'cloudevent',
@@ -92,13 +96,15 @@ describe('parseOptions', () => {
       cliOpts: ['bin/node', '/index.js'],
       envVars: {
         PORT: '1234',
+        HOST: '0.0.0.0',
         FUNCTION_TARGET: 'helloWorld',
         FUNCTION_SIGNATURE_TYPE: 'cloudevent',
         FUNCTION_SOURCE: '/source',
         CLOUD_RUN_TIMEOUT_SECONDS: '2',
       },
       expectedOptions: {
         port: '1234',
+        host: '0.0.0.0',
         target: 'helloWorld',
         sourceLocation: resolve('/source'),
         signatureType: 'cloudevent',
@@ -119,16 +125,20 @@ describe('parseOptions', () => {
         'cloudevent',
         '--source=/source',
         '--timeout=3',
+        '--host',
+        '0.0.0.0',
       ],
       envVars: {
         PORT: '4567',
+        HOST: '127.0.0.1',
         FUNCTION_TARGET: 'fooBar',
         FUNCTION_SIGNATURE_TYPE: 'event',
         FUNCTION_SOURCE: '/somewhere/else',
         CLOUD_RUN_TIMEOUT_SECONDS: '5',
       },
       expectedOptions: {
         port: '1234',
+        host: '0.0.0.0',
         target: 'helloWorld',
         sourceLocation: resolve('/source'),
         signatureType: 'cloudevent',