Add deprecation warnings for functions.config() API

src/commands/functions-config-clone.ts

@@ -8,6 +8,7 @@
 import * as functionsConfig from "../functionsConfig";
 import { functionsConfigClone } from "../functionsConfigClone";
 import * as utils from "../utils";
+import { logFunctionsConfigDeprecationWarning } from "../functions/deprecationWarnings";
 
 export const command = new Command("functions:config:clone")
   .description("clone environment config from another project")
@@ -28,22 +29,22 @@
   ])
   .before(functionsConfig.ensureApi)
   .action(async (options) => {
     const projectId = needProjectId(options);
     if (!options.from) {
       throw new FirebaseError(
         `Must specify a source project in ${clc.bold("--from <projectId>")} option.`,
       );
     } else if (options.from === projectId) {
       throw new FirebaseError("From project and destination can't be the same project.");
     } else if (options.only && options.except) {
       throw new FirebaseError("Cannot use both --only and --except at the same time.");
     }
 
     let only: string[] | undefined;
     let except: string[] = [];
     if (options.only) {
       only = options.only.split(",");
     } else if (options.except) {
       except = options.except.split(",");
     }
 
@@ -56,4 +57,5 @@
         "firebase deploy --only functions",
       )}\n`,
     );
+    logFunctionsConfigDeprecationWarning();
   });

src/commands/functions-config-get.ts

@@ -6,6 +6,7 @@ import { logger } from "../logger";
 import { needProjectId } from "../projectUtils";
 import { requirePermissions } from "../requirePermissions";
 import * as functionsConfig from "../functionsConfig";
+import { logFunctionsConfigDeprecationWarning } from "../functions/deprecationWarnings";
 
 async function materialize(projectId: string, path?: string): Promise<any> {
   if (path === undefined) {
@@ -31,5 +32,6 @@ export const command = new Command("functions:config:get [path]")
   .action(async (path, options) => {
     const result = await materialize(needProjectId(options), path);
     logger.info(JSON.stringify(result, null, 2));
+    logFunctionsConfigDeprecationWarning();
     return result;
   });

src/commands/functions-config-set.ts

@@ -7,6 +7,7 @@ import { needProjectId } from "../projectUtils";
 import { requirePermissions } from "../requirePermissions";
 import * as functionsConfig from "../functionsConfig";
 import * as utils from "../utils";
+import { logFunctionsConfigDeprecationWarning } from "../functions/deprecationWarnings";
 
 export const command = new Command("functions:config:set [values...]")
   .description("set environment config with key=value syntax")
@@ -49,4 +50,5 @@ export const command = new Command("functions:config:set [values...]")
         "firebase deploy --only functions",
       )}\n`,
     );
+    logFunctionsConfigDeprecationWarning();
   });

src/commands/functions-config-unset.ts

@@ -8,6 +8,7 @@ import * as functionsConfig from "../functionsConfig";
 import * as runtimeconfig from "../gcp/runtimeconfig";
 import * as utils from "../utils";
 import { FirebaseError } from "../error";
+import { logFunctionsConfigDeprecationWarning } from "../functions/deprecationWarnings";
 
 export const command = new Command("functions:config:unset [keys...]")
   .description("unset environment config at the specified path(s)")
@@ -44,4 +45,5 @@ export const command = new Command("functions:config:unset [keys...]")
         "firebase deploy --only functions",
       )}\n`,
     );
+    logFunctionsConfigDeprecationWarning();
   });

src/deploy/functions/prepareFunctionsUpload.ts

@@ -13,6 +13,7 @@ import * as functionsConfig from "../../functionsConfig";
 import * as utils from "../../utils";
 import * as fsAsync from "../../fsAsync";
 import * as projectConfig from "../../functions/projectConfig";
+import { logFunctionsConfigDeprecationWarning } from "../../functions/deprecationWarnings";
 
 const CONFIG_DEST_FILE = ".runtimeconfig.json";
 
@@ -99,6 +100,9 @@ async function packageSource(
         name: CONFIG_DEST_FILE,
         mode: 420 /* 0o644 */,
       });
+
+      // Log deprecation warning when runtime config is being packaged
+      logFunctionsConfigDeprecationWarning();
     }
     await pipeAsync(archive, fileStream);
   } catch (err: any) {

src/experiments.ts

@@ -57,6 +57,14 @@ export const ALL_EXPERIMENTS = experiments({
       "of how that image was created.",
     public: true,
   },
+  dangerouslyAllowFunctionsConfig: {
+    shortDescription: "Allows the use of deprecated functions.config() API",
+    fullDescription:
+      "The functions.config() API is deprecated and will be removed on December 31, 2025. " +
+      "This experiment allows continued use of the API during the migration period.",
+    default: true,
+    public: true,
+  },
 
   // Emulator experiments
   emulatoruisnapshot: {

src/functions/deprecationWarnings.ts

@@ -0,0 +1,18 @@
+import { logWarning } from "../utils";
+
+const FUNCTIONS_CONFIG_DEPRECATION_MESSAGE =
+  "DEPRECATION NOTICE: Action required to deploy after Dec 31, 2025\n" +
+  "  functions.config() API is deprecated.\n" +
+  "  Cloud Runtime Configuration API, the Google Cloud service used to store function configuration data, will be shut down on December 31, 2025. As a result, you must migrate away from using functions.config() to continue deploying your functions after December 31, 2025.\n" +
+  "  What this means for you:\n" +
+  "  The Firebase CLI commands for managing this configuration (functions:config:set, get, unset, clone, and export) are deprecated. These commands no longer work after December 31, 2025.\n" +
+  "  firebase deploy command will fail for functions that use the legacy functions.config() API after December 31, 2025.\n" +
+  "  Existing deployments will continue to work with their current configuration.\n" +
+  "  See your migration options at: https://firebase.google.com/docs/functions/config-env#migrate-to-dotenv";
+
+/**
+ * Logs a deprecation warning for functions.config() usage
+ */
+export function logFunctionsConfigDeprecationWarning(): void {
+  logWarning(FUNCTIONS_CONFIG_DEPRECATION_MESSAGE);
+}