fix(amplify-provider-awscloudformation): specify 127.0.0.1 as hostname (

#6780)

* fix(amplify-provider-awscloudformation): specify 0.0.0.0 as hostname for adminui login server to force listening on ipv4 instead of ipv6 when available.

packages/amplify-provider-awscloudformation/src/__tests__/utils/admin-login-server.test.ts

@@ -0,0 +1,44 @@
+import { AdminLoginServer } from '../../utils/admin-login-server';
+import { $TSContext } from 'amplify-cli-core';
+import { FunctionRuntimeLifecycleManager } from 'amplify-function-plugin-interface';
+
+const runtimePlugin_stub = ({
+  checkDependencies: jest.fn().mockResolvedValue({ hasRequiredDependencies: true }),
+  build: jest.fn().mockResolvedValue({ rebuilt: true }),
+} as unknown) as jest.Mocked<FunctionRuntimeLifecycleManager>;
+
+const context_stub = ({
+  amplify: {
+    readBreadcrumbs: jest.fn().mockReturnValue({ pluginId: 'testPluginId' }),
+    loadRuntimePlugin: jest.fn().mockResolvedValue(runtimePlugin_stub),
+    updateamplifyMetaAfterBuild: jest.fn(),
+  },
+} as unknown) as jest.Mocked<$TSContext>;
+
+const useMock = jest.fn();
+const postMock = jest.fn(async () => {});
+const listenMock = jest.fn();
+
+jest.mock('express', () => {
+  return () => {
+    return {
+      use: useMock,
+      post: postMock,
+      listen: listenMock,
+    };
+  };
+});
+
+describe('AdminLoginServer', () => {
+  test('run server with 0.0.0.0', async () => {
+    const adminLoginServer = new AdminLoginServer('appId', 'http://example.com', context_stub.print);
+
+    await new Promise<void>(resolve => {
+      adminLoginServer.startServer(() => {});
+      resolve();
+    });
+    expect(useMock).toBeCalled();
+    expect(postMock).toBeCalled();
+    expect(listenMock).toBeCalledWith(4242, '0.0.0.0');
+  });
+});

packages/amplify-provider-awscloudformation/src/utils/admin-login-server.ts

@@ -16,6 +16,7 @@ export class AdminLoginServer {
   private port = 4242; // placeholder
   private server: http.Server;
   private print: $TSContext['print'];
+  private host = '0.0.0.0'; // using this ip address for the host forces express to listen on IPV4 even if IPV6 is available
 
   private corsOptions: {
     origin: string[];
@@ -38,7 +39,12 @@ export class AdminLoginServer {
 
   public async startServer(callback: () => void) {
     await this.setupRoute(callback);
-    this.server = this.app.listen(this.getPort());
+    // Need to specify hostname for WSL
+    this.server = this.app.listen(this.getPort(), this.getHost());
+  }
+
+  private getHost() {
+    return this.host;
   }
 
   // TODO: scan for available ports across a range like mock