chore: remove usage for stats endpoint

src/plugins/files/server/usage/integration_tests/usage.test.ts

@@ -44,9 +44,11 @@ describe('Files usage telemetry', () => {
       request.post(root, `/api/files/shares/${fileKind}/${file3.id}`).send({}).expect(200),
     ]);
 
-    const { body } = await request.get(root, `/api/stats?extended=true&legacy=true`);
+    const { body } = await request
+      .post(root, '/api/telemetry/v2/clusters/_stats')
+      .send({ unencrypted: true });
 
-    expect(body.usage.files).toMatchInlineSnapshot(`
+    expect(body[0].stats.stack_stats.kibana.plugins.files).toMatchInlineSnapshot(`
       Object {
         "countByExtension": Array [
           Object {

src/plugins/usage_collection/server/routes/stats/README.md

@@ -8,9 +8,9 @@ However, the information detailed above can be extended, with the combination of
 
 | Query Parameter | Default value | Description |
 |:----------------|:-------------:|:------------|
-|`extended`|`false`|When `true`, it adds `clusterUuid` and `usage`. The latter contains the information reported by all the Usage Collectors registered in the Kibana server. It may throw `503 Stats not ready` if any of the collectors is not fully initialized yet.|
-|`legacy`|`false`|By default, when `extended=true`, the key names of the data in `usage` are transformed into API-friendlier `snake_case` format (i.e.: `clusterUuid` is transformed to `cluster_uuid`). When this parameter is `true`, the data is returned as-is.|
-|`exclude_usage`|`false`|When `true`, and `extended=true`, it will report `clusterUuid` but no `usage`.|
+|`extended`|`false`|When `true`, it adds `clusterUuid`.|
+|`legacy`|`false`|By default, when `extended=true`, the key names are transformed into API-friendlier `snake_case` format (i.e.: `clusterUuid` is transformed to `cluster_uuid`). When this parameter is `true`, the data is returned as-is.|
+|`exclude_usage`|`true`| Deprecated. Only kept for backward-compatibility. Setting this to `false` has no effect. Usage is always excluded. | 
 
 ## Known use cases
 

src/plugins/usage_collection/server/routes/stats/stats.ts

@@ -8,14 +8,12 @@
 
 import { schema } from '@kbn/config-schema';
 import { i18n } from '@kbn/i18n';
-import defaultsDeep from 'lodash/defaultsDeep';
 import { firstValueFrom, Observable } from 'rxjs';
 
 import {
   ElasticsearchClient,
   IRouter,
   type MetricsServiceSetup,
-  SavedObjectsClientContract,
   ServiceStatus,
   ServiceStatusLevels,
 } from '@kbn/core/server';
@@ -51,14 +49,6 @@ export function registerStatsRoute({
   metrics: MetricsServiceSetup;
   overallStatus$: Observable<ServiceStatus>;
 }) {
-  const getUsage = async (
-    esClient: ElasticsearchClient,
-    savedObjectsClient: SavedObjectsClientContract
-  ): Promise<UsageObject> => {
-    const usage = await collectorSet.bulkFetchUsage(esClient, savedObjectsClient);
-    return collectorSet.toObject(usage);
-  };
-
   const getClusterUuid = async (asCurrentUser: ElasticsearchClient): Promise<string> => {
     const body = await asCurrentUser.info({ filter_path: 'cluster_uuid' });
     const { cluster_uuid: uuid } = body;
@@ -77,69 +67,34 @@ export function registerStatsRoute({
           extended: schema.oneOf([schema.literal(''), schema.boolean()], { defaultValue: false }),
           legacy: schema.oneOf([schema.literal(''), schema.boolean()], { defaultValue: false }),
           exclude_usage: schema.oneOf([schema.literal(''), schema.boolean()], {
-            defaultValue: false,
+            defaultValue: true,
           }),
         }),
       },
     },
     async (context, req, res) => {
       const isExtended = req.query.extended === '' || req.query.extended;
       const isLegacy = req.query.legacy === '' || req.query.legacy;
-      const shouldGetUsage = req.query.exclude_usage === false;
 
       let extended;
       if (isExtended) {
         const core = await context.core;
         const { asCurrentUser } = core.elasticsearch.client;
-        const savedObjectsClient = core.savedObjects.client;
-
-        const [usage, clusterUuid] = await Promise.all([
-          shouldGetUsage
-            ? getUsage(asCurrentUser, savedObjectsClient)
-            : Promise.resolve<UsageObject>({}),
-          getClusterUuid(asCurrentUser),
-        ]);
-
-        let modifiedUsage = usage;
-        if (isLegacy) {
-          // In an effort to make telemetry more easily augmented, we need to ensure
-          // we can passthrough the data without every part of the process needing
-          // to know about the change; however, to support legacy use cases where this
-          // wasn't true, we need to be backwards compatible with how the legacy data
-          // looked and support those use cases here.
-          modifiedUsage = Object.keys(usage).reduce((accum, usageKey) => {
-            if (usageKey === 'kibana') {
-              accum = {
-                ...accum,
-                ...usage[usageKey],
-              };
-            } else if (usageKey === 'reporting') {
-              accum = {
-                ...accum,
-                xpack: {
-                  ...accum.xpack,
-                  reporting: usage[usageKey],
-                },
-              };
-            } else {
-              // I don't think we need to it this for the above conditions, but do it for most as it will
-              // match the behavior done in monitoring/bulk_uploader
-              defaultsDeep(accum, { [usageKey]: usage[usageKey] });
-            }
 
-            return accum;
-          }, {} as UsageObject);
+        const usage = {} as UsageObject;
+        const clusterUuid = await getClusterUuid(asCurrentUser);
 
-          extended = {
-            usage: modifiedUsage,
-            clusterUuid,
-          };
-        } else {
-          extended = collectorSet.toApiFieldNames({
-            usage: modifiedUsage,
-            clusterUuid,
-          });
-        }
+        // In an effort to make telemetry more easily augmented, we need to ensure
+        // we can passthrough the data without every part of the process needing
+        // to know about the change; however, to support legacy use cases where this
+        // wasn't true, we need to be backwards compatible with how the legacy data
+        // looked and support those use cases here.
+        extended = isLegacy
+          ? { usage, clusterUuid }
+          : collectorSet.toApiFieldNames({
+              usage,
+              clusterUuid,
+            });
       }
 
       // Guaranteed to resolve immediately due to replay effect on getOpsMetrics$

test/api_integration/apis/stats/stats.js

@@ -91,6 +91,7 @@ export default function ({ getService }) {
           .then(({ body }) => {
             expect(body.cluster_uuid).to.be.a('string');
             expect(body.usage).to.be.an('object'); // no usage collectors have been registered so usage is an empty object
+            expect(body.usage).to.eql({});
             assertStatsAndMetrics(body);
           });
       });
@@ -103,6 +104,7 @@ export default function ({ getService }) {
           .then(({ body }) => {
             expect(body.cluster_uuid).to.be.a('string');
             expect(body.usage).to.be.an('object');
+            expect(body.usage).to.eql({});
             assertStatsAndMetrics(body);
           });
       });
@@ -116,6 +118,7 @@ export default function ({ getService }) {
             .then(({ body }) => {
               expect(body.clusterUuid).to.be.a('string');
               expect(body.usage).to.be.an('object'); // no usage collectors have been registered so usage is an empty object
+              expect(body.usage).to.eql({});
               assertStatsAndMetrics(body, true);
             });
         });