Implement ListSupportedRuntime usage for runtimes (dynamically popula…

src/apphosting/backend.ts

@@ -52,7 +52,7 @@
     // SSL.
     const maybeNodeError = err as { cause: { code: string }; code: string };
     if (
       /HANDSHAKE_FAILURE/.test(maybeNodeError?.cause?.code) ||
       "EPROTO" === maybeNodeError?.code
     ) {
       return false;
@@ -134,12 +134,21 @@
     if (nonInteractive) {
       runtime = DEFAULT_RUNTIME;
     } else {
+      const choices: Choice<string>[] = [{ name: "Node.js (default)", value: DEFAULT_RUNTIME }];
+      try {
+        const supportedRuntimes = await apphosting.listSupportedRuntimes(projectId, location);
+        for (const r of supportedRuntimes) {
+          if (r.runtimeId !== DEFAULT_RUNTIME) {
+            choices.push({ name: r.runtimeId, value: r.runtimeId });
+          }
+        }
+      } catch (err) {
+        logWarning("Failed to list supported runtimes. Falling back to default.");
+      }
+
       runtime = await select({
         message: "Which runtime do you want to use?",
-        choices: [
-          { name: "Node.js (default)", value: DEFAULT_RUNTIME },
-          { name: "Node.js 22", value: "nodejs22" },
-        ],
+        choices: choices,
         default: DEFAULT_RUNTIME,
       });
     }
@@ -337,7 +346,7 @@
  * Prompts the user for a backend id and verifies that it doesn't match a pre-existing backend.
  */
 export async function promptNewBackendId(projectId: string, location: string): Promise<string> {
   while (true) {
     const backendId = await input({
       default: "my-web-app",
       message: "Provide a name for your backend [1-30 characters]",
@@ -650,7 +659,7 @@
     message: locationDisambugationPrompt,
     choices: [...backendsByLocation.keys()],
   });
   return backendsByLocation.get(location)!;
 }
 
 /**

src/gcp/apphosting.spec.ts

@@ -278,5 +278,17 @@ describe("apphosting", () => {
         queryParams: { pageToken: "2" },
       });
     });
+
+    it("lists supported runtimes", async () => {
+      get.resolves({
+        body: {
+          supportedRuntimes: [{ runtimeId: "nodejs22" }],
+        },
+      });
+      await expect(apphosting.listSupportedRuntimes("p", "l")).to.eventually.deep.equal([
+        { runtimeId: "nodejs22" },
+      ]);
+      expect(get).to.have.been.calledWithMatch("projects/p/locations/l/supportedRuntimes");
+    });
   });
 });

src/gcp/apphosting.ts

@@ -58,6 +58,18 @@
   automaticBaseImageUpdatesDisabled?: boolean;
 }
 
+export interface SupportedRuntime {
+  name: string;
+  runtimeId: string;
+  automaticBaseImageUpdatesSupported: boolean;
+  deprecateTime?: string;
+  decommissionTime?: string;
+}
+
+export interface ListSupportedRuntimesResponse {
+  supportedRuntimes: SupportedRuntime[];
+}
+
 export interface ManagedResource {
   runService: { service: string };
 }
@@ -298,7 +310,7 @@
   done: boolean;
   // oneof result
   error?: Status;
   response?: any;
   // end oneof result
 }
 
@@ -711,17 +723,29 @@
   return locations;
 }
 
+/**
+ * Lists supported runtimes for a given project and location.
+ */
+export async function listSupportedRuntimes(
+  projectId: string,
+  location: string,
+): Promise<SupportedRuntime[]> {
+  const name = `projects/${projectId}/locations/${location}/supportedRuntimes`;
+  const res = await client.get<ListSupportedRuntimesResponse>(name);
+  return res.body.supportedRuntimes || [];
+}
+
 /**
  * Ensure that the App Hosting API is enabled on the project.
  */
 export async function ensureApiEnabled(options: any): Promise<void> {
   const projectId = needProjectId(options);
   return await ensure(projectId, apphostingOrigin(), "app hosting", true);
 }
 
 /**
  * Generates the next build ID to fit with the naming scheme of the backend API.
  * @param counter Overrides the counter to use, avoiding an API call.
  */
 export async function getNextRolloutId(
   projectId: string,