Only show "Not defined" in environment selector if there are actually

documents without service.environment set

x-pack/plugins/apm/public/components/app/Settings/anomaly_detection/add_environments.tsx

@@ -44,8 +44,7 @@ export const AddEnvironments = ({
     { preservePreviousData: false }
   );
 
-  const environments = [...data, ENVIRONMENT_NOT_DEFINED];
-  const environmentOptions = environments.map((env) => ({
+  const environmentOptions = data.map((env) => ({
     label: env === ENVIRONMENT_NOT_DEFINED ? NOT_DEFINED_OPTION_LABEL : env,
     value: env,
     disabled: currentEnvironments.includes(env),

x-pack/plugins/apm/server/lib/environments/get_all_environments.test.ts

@@ -27,4 +27,16 @@ describe('getAllEnvironments', () => {
 
     expect(mock.params).toMatchSnapshot();
   });
+
+  it('fetches all environments with includeMissing', async () => {
+    mock = await inspectSearchParams((setup) =>
+      getAllEnvironments({
+        serviceName: 'test',
+        setup,
+        includeMissing: true,
+      })
+    );
+
+    expect(mock.params).toMatchSnapshot();
+  });
 });

x-pack/plugins/apm/server/lib/environments/get_all_environments.ts

@@ -10,13 +10,16 @@ import {
   SERVICE_NAME,
   SERVICE_ENVIRONMENT,
 } from '../../../common/elasticsearch_fieldnames';
+import { ENVIRONMENT_NOT_DEFINED } from '../../../common/environment_filter_values';
 
 export async function getAllEnvironments({
   serviceName,
   setup,
+  includeMissing = false,
 }: {
   serviceName?: string;
   setup: Setup;
+  includeMissing?: boolean;
 }) {
   const { client, indices } = setup;
 
@@ -48,6 +51,7 @@ export async function getAllEnvironments({
           terms: {
             field: SERVICE_ENVIRONMENT,
             size: 100,
+            missing: includeMissing ? ENVIRONMENT_NOT_DEFINED : undefined,
           },
         },
       },

x-pack/plugins/apm/server/routes/settings/anomaly_detection.ts

@@ -50,6 +50,6 @@ export const anomalyDetectionEnvironmentsRoute = createRoute(() => ({
   path: '/api/apm/settings/anomaly-detection/environments',
   handler: async ({ context, request }) => {
     const setup = await setupRequest(context, request);
-    return await getAllEnvironments({ setup });
+    return await getAllEnvironments({ setup, includeMissing: true });
   },
 }));