cli: only consider PORT environment variable for module federation remotes

Signed-off-by: MT Lewis <mtlewis@users.noreply.github.com>

packages/cli/src/lib/bundler/config.ts

@@ -14,7 +14,11 @@
  * limitations under the License.
  */
 
-import { BackendBundlingOptions, BundlingOptions } from './types';
+import {
+  BackendBundlingOptions,
+  BundlingOptions,
+  ModuleFederationOptions,
+} from './types';
 import { posix as posixPath, resolve as resolvePath, dirname } from 'path';
 import chalk from 'chalk';
 import webpack, { ProvidePlugin } from 'webpack';
@@ -46,24 +50,32 @@ import { hasReactDomClient } from './hasReactDomClient';
 
 const BUILD_CACHE_ENV_VAR = 'BACKSTAGE_CLI_EXPERIMENTAL_BUILD_CACHE';
 
-export function resolveBaseUrl(config: Config): URL {
+export function resolveBaseUrl(
+  config: Config,
+  moduleFederation?: ModuleFederationOptions,
+): URL {
   const baseUrl = config.getOptionalString('app.baseUrl');
 
+  const defaultBaseUrl =
+    moduleFederation?.mode === 'remote'
+      ? `http://localhost:${process.env.PORT ?? '3000'}`
+      : 'http://localhost:3000';
+
   try {
-    return new URL(
-      baseUrl ?? '/',
-      `http://localhost:${process.env.PORT ?? '3000'}`,
-    );
+    return new URL(baseUrl ?? '/', defaultBaseUrl);
   } catch (error) {
     throw new Error(`Invalid app.baseUrl, ${error}`);
   }
 }
 
-export function resolveEndpoint(config: Config): {
+export function resolveEndpoint(
+  config: Config,
+  moduleFederation?: ModuleFederationOptions,
+): {
   host: string;
   port: number;
 } {
-  const url = resolveBaseUrl(config);
+  const url = resolveBaseUrl(config, moduleFederation);
 
   return {
     host: config.getOptionalString('app.listen.host') ?? url.hostname,
@@ -114,7 +126,13 @@ export async function createConfig(
   paths: BundlingPaths,
   options: BundlingOptions,
 ): Promise<webpack.Configuration> {
-  const { checksEnabled, isDev, frontendConfig, publicSubPath = '' } = options;
+  const {
+    checksEnabled,
+    isDev,
+    frontendConfig,
+    moduleFederation,
+    publicSubPath = '',
+  } = options;
 
   const { plugins, loaders } = transforms(options);
   // Any package that is part of the monorepo but outside the monorepo root dir need
@@ -122,14 +140,17 @@ export async function createConfig(
   const { packages } = await getPackages(cliPaths.targetDir);
   const externalPkgs = packages.filter(p => !isChildPath(paths.root, p.dir));
 
-  const validBaseUrl = resolveBaseUrl(frontendConfig);
+  const validBaseUrl = resolveBaseUrl(frontendConfig, moduleFederation);
   let publicPath = validBaseUrl.pathname.replace(/\/$/, '');
   if (publicSubPath) {
     publicPath = `${publicPath}${publicSubPath}`.replace('//', '/');
   }
 
   if (isDev) {
-    const { host, port } = resolveEndpoint(options.frontendConfig);
+    const { host, port } = resolveEndpoint(
+      options.frontendConfig,
+      options.moduleFederation,
+    );
 
     plugins.push(
       new ReactRefreshPlugin({

packages/cli/src/lib/bundler/server.ts

@@ -130,8 +130,11 @@ DEPRECATION WARNING: React Router Beta is deprecated and support for it will be
   }
 
   const { frontendConfig, fullConfig } = cliConfig;
-  const url = resolveBaseUrl(frontendConfig);
-  const { host, port } = resolveEndpoint(frontendConfig);
+  const url = resolveBaseUrl(frontendConfig, options.moduleFederation);
+  const { host, port } = resolveEndpoint(
+    frontendConfig,
+    options.moduleFederation,
+  );
 
   const detectedModulesEntryPoint = await createDetectedModulesEntryPoint({
     config: fullConfig,