[9.3] Gracefully handle deprecated telemetry config (#266029)

src/platform/plugins/shared/telemetry/moon.yml

@@ -46,6 +46,7 @@ dependsOn:
   - '@kbn/logging'
   - '@kbn/core-security-server'
   - '@kbn/telemetry-config'
+  - '@kbn/config'
 tags:
   - plugin
   - prod

src/platform/plugins/shared/telemetry/server/config/config.test.ts

@@ -7,8 +7,24 @@
  * License v3.0 only", or the "Server Side Public License, v 1".
  */
 
+import { applyDeprecations, configDeprecationFactory } from '@kbn/config';
+import { configDeprecationsMock } from '@kbn/core/server/mocks';
 import { config } from './config';
 
+const applyConfigDeprecations = (telemetrySettings: Record<string, unknown> = {}) => {
+  const deprecationContext = configDeprecationsMock.createContext();
+  const deprecations = config.deprecations!(configDeprecationFactory);
+  const { config: migrated } = applyDeprecations(
+    { telemetry: telemetrySettings },
+    deprecations.map((deprecation) => ({
+      deprecation,
+      path: 'telemetry',
+      context: deprecationContext,
+    }))
+  );
+  return migrated as Record<string, Record<string, unknown>>;
+};
+
 describe('config', () => {
   const baseContext = {
     dist: true,
@@ -62,4 +78,51 @@ describe('config', () => {
       }
     );
   });
+
+  describe('deprecations: telemetry.enabled', () => {
+    describe('when telemetry.enabled is set to a falsy value, the plugin stays enabled and telemetry is opted out', () => {
+      test.each([false, 'false', 'False', 'FALSE'])(
+        'migrates telemetry.enabled: %p → removes enabled, sets optIn and allowChangingOptInStatus to false',
+        (enabledValue) => {
+          const migrated = applyConfigDeprecations({ enabled: enabledValue });
+
+          expect(migrated.telemetry.enabled).toBeUndefined();
+          expect(migrated.telemetry.optIn).toBe(false);
+          expect(migrated.telemetry.allowChangingOptInStatus).toBe(false);
+        }
+      );
+
+      test.each([false, 'false', 'False', 'FALSE'])(
+        'also disables tracing and metrics when telemetry.enabled: %p',
+        (enabledValue) => {
+          const migrated = applyConfigDeprecations({ enabled: enabledValue });
+
+          const telemetry = migrated.telemetry as Record<string, Record<string, unknown>>;
+          expect(telemetry.tracing?.enabled).toBe(false);
+          expect(telemetry.metrics?.enabled).toBe(false);
+        }
+      );
+    });
+
+    describe('when telemetry.enabled is absent or truthy, the deprecation does not fire', () => {
+      test('does not modify config when telemetry.enabled is not set', () => {
+        const migrated = applyConfigDeprecations({});
+
+        expect(migrated.telemetry.enabled).toBeUndefined();
+        expect(migrated.telemetry.optIn).toBeUndefined();
+        expect(migrated.telemetry.allowChangingOptInStatus).toBeUndefined();
+      });
+
+      test.each([true, 'true', 'True', 'TRUE'])(
+        'does not modify config when telemetry.enabled: %p',
+        (enabledValue) => {
+          const migrated = applyConfigDeprecations({ enabled: enabledValue });
+
+          expect(migrated.telemetry.enabled).toBe(enabledValue);
+          expect(migrated.telemetry.optIn).toBeUndefined();
+          expect(migrated.telemetry.allowChangingOptInStatus).toBeUndefined();
+        }
+      );
+    });
+  });
 });

src/platform/plugins/shared/telemetry/server/config/config.ts

@@ -76,7 +76,11 @@ export const config: PluginConfigDescriptor<TelemetryConfigType> = {
   },
   deprecations: () => [
     (cfg) => {
-      if (cfg.telemetry?.enabled === false) {
+      const raw = cfg.telemetry?.enabled;
+      const isDisabling =
+        raw === false || (typeof raw === 'string' && raw.toLowerCase() === 'false');
+
+      if (isDisabling) {
         return {
           set: [
             { path: 'telemetry.optIn', value: false },

src/platform/plugins/shared/telemetry/tsconfig.json

@@ -41,6 +41,7 @@
     "@kbn/logging",
     "@kbn/core-security-server",
     "@kbn/telemetry-config",
+    "@kbn/config",
   ],
   "exclude": [
     "target/**/*",