Merge pull request #24300 from backstage/rugvip/app-mode

app-backend,cli: move backstage-app-mode injection to build time

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

@@ -41,6 +41,10 @@ export async function buildBundle(options: BuildOptions) {
   const { statsJsonEnabled, schema: configSchema } = options;
 
   const paths = resolveBundlingPaths(options);
+  const publicPaths = await resolveOptionalBundlingPaths({
+    entry: 'src/index-public-experimental',
+    dist: 'dist/public',
+  });
 
   const detectedModulesEntryPoint = await createDetectedModulesEntryPoint({
     config: options.fullConfig,
@@ -57,20 +61,22 @@ export async function buildBundle(options: BuildOptions) {
     await createConfig(paths, {
       ...commonConfigOptions,
       additionalEntryPoints: detectedModulesEntryPoint,
+      appMode: publicPaths ? 'protected' : 'public',
     }),
   ];
 
-  const publicPaths = await resolveOptionalBundlingPaths({
-    entry: 'src/index-public-experimental',
-    dist: 'dist/public',
-  });
   if (publicPaths) {
     console.log(
       chalk.yellow(
         `⚠️  WARNING: The app /public entry point is an experimental feature that may receive immediate breaking changes.`,
       ),
     );
-    configs.push(await createConfig(publicPaths, commonConfigOptions));
+    configs.push(
+      await createConfig(publicPaths, {
+        ...commonConfigOptions,
+        appMode: 'public',
+      }),
+    );
   }
 
   const isCi = yn(process.env.CI, { default: false });

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

@@ -130,6 +130,9 @@ export async function createConfig(
 
   plugins.push(
     new HtmlWebpackPlugin({
+      meta: {
+        'backstage-app-mode': options?.appMode ?? 'public',
+      },
       template: paths.targetHtml,
       templateParameters: {
         publicPath,

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

@@ -27,6 +27,8 @@ export type BundlingOptions = {
   additionalEntryPoints?: string[];
   // Path to append to the detected public path, e.g. '/public'
   publicSubPath?: string;
+  // Mode that the app is running in, 'protected' or 'public', default is 'public'
+  appMode?: string;
 };
 
 export type ServeOptions = BundlingPathsOptions & {