Dynamically load available locations from App Hosting API (#6609)

Instead of hard-coding supported regions, we dynamically fetch the list of supported regions from the API.

This is great especially when a org policy is set to restrict region availability for a project!

Author: taeold

src/commands/frameworks-backends-create.ts

@@ -7,6 +7,7 @@ import { ensureApiEnabled } from "../gcp/frameworks";
 
 export const command = new Command("backends:create")
   .description("Create a backend in a Firebase project")
+  .option("-l, --location <location>", "Specify the region of the backend", "")
   .before(ensureApiEnabled)
   .before(requireInteractive)
   .action(async (options: Options) => {

src/commands/frameworks-backends-delete.ts

@@ -6,7 +6,7 @@ import * as gcp from "../gcp/frameworks";
 import { promptOnce } from "../prompt";
 import * as utils from "../utils";
 import { logger } from "../logger";
-import { DEFAULT_REGION, ALLOWED_REGIONS } from "../init/features/frameworks/constants";
+import { DEFAULT_REGION } from "../init/features/frameworks/constants";
 import { ensureApiEnabled } from "../gcp/frameworks";
 
 const Table = require("cli-table");
@@ -36,12 +36,13 @@ export const command = new Command("backends:delete")
     }
 
     if (!location) {
+      const allowedLocations = (await gcp.listLocations(projectId)).map((loc) => loc.locationId);
       location = await promptOnce({
         name: "region",
         type: "list",
         default: DEFAULT_REGION,
         message: "Please select the region of the backend you'd like to delete:",
-        choices: ALLOWED_REGIONS,
+        choices: allowedLocations,
       });
     }
 

src/gcp/frameworks.ts

@@ -125,7 +125,6 @@ export async function getBackend(
 ): Promise<Backend> {
   const name = `projects/${projectId}/locations/${location}/backends/${backendId}`;
   const res = await client.get<Backend>(name);
-
   return res.body;
 }
 
@@ -175,6 +174,32 @@ export async function createBuild(
   return res.body;
 }
 
+export interface Location {
+  name: string;
+  locationId: string;
+}
+
+interface ListLocationsResponse {
+  locations: Location[];
+  nextPageToken?: string;
+}
+
+/**
+ * Lists information about the supported locations.
+ */
+export async function listLocations(projectId: string): Promise<Location[]> {
+  let pageToken;
+  let locations: Location[] = [];
+  do {
+    const response = await client.get<ListLocationsResponse>(`projects/${projectId}/locations`);
+    if (response.body.locations && response.body.locations.length > 0) {
+      locations = locations.concat(response.body.locations);
+    }
+    pageToken = response.body.nextPageToken;
+  } while (pageToken);
+  return locations;
+}
+
 /**
  * Ensure that Frameworks API is enabled on the project.
  */

src/init/features/frameworks/constants.ts

@@ -1,4 +1,3 @@
 export const DEFAULT_REGION = "us-central1";
-export const ALLOWED_REGIONS = [{ name: "us-central1 (Iowa)", value: "us-central1" }];
 export const DEFAULT_DEPLOY_METHOD = "github";
 export const ALLOWED_DEPLOY_METHODS = [{ name: "Deploy using github", value: "github" }];

src/init/features/frameworks/index.ts

@@ -9,7 +9,7 @@ import { Repository } from "../../../gcp/cloudbuild";
 import { API_VERSION } from "../../../gcp/frameworks";
 import { FirebaseError } from "../../../error";
 import { promptOnce } from "../../../prompt";
-import { DEFAULT_REGION, ALLOWED_REGIONS } from "./constants";
+import { DEFAULT_REGION } from "./constants";
 import { ensure } from "../../../ensureApiEnabled";
 
 const frameworksPollerOptions: Omit<poller.OperationPollerOptions, "operationResourceName"> = {
@@ -32,17 +32,19 @@ export async function doSetup(setup: any, projectId: string): Promise<void> {
     ensure(projectId, "artifactregistry.googleapis.com", "frameworks", true),
   ]);
 
+  const allowedLocations = (await gcp.listLocations(projectId)).map((loc) => loc.locationId);
+
+  if (setup.location) {
+    if (!allowedLocations.includes(setup.location)) {
+      throw new FirebaseError(
+        `Invalid location ${setup.location}. Valid choices are ${allowedLocations.join(", ")}`
+      );
+    }
+  }
+
   logBullet("First we need a few details to create your backend.");
 
-  const location = await promptOnce({
-    name: "region",
-    type: "list",
-    default: DEFAULT_REGION,
-    message:
-      "Please select a region " +
-      `(${clc.yellow("info")}: Your region determines where your backend is located):\n`,
-    choices: ALLOWED_REGIONS,
-  });
+  const location: string = setup.location || (await promptLocation(projectId, allowedLocations));
 
   logSuccess(`Region set to ${location}.\n`);
 
@@ -78,6 +80,18 @@ export async function doSetup(setup: any, projectId: string): Promise<void> {
   }
 }
 
+async function promptLocation(projectId: string, locations: string[]): Promise<string> {
+  return await promptOnce({
+    name: "region",
+    type: "list",
+    default: DEFAULT_REGION,
+    message:
+      "Please select a region " +
+      `(${clc.yellow("info")}: Your region determines where your backend is located):\n`,
+    choices: locations.map((loc) => ({ value: loc })),
+  });
+}
+
 function toBackend(cloudBuildConnRepo: Repository): Omit<Backend, BackendOutputOnlyFields> {
   return {
     servingLocality: "GLOBAL_ACCESS",