task: add sdk version metric (#1828)

* task: add sdk version metric

src/lib/metrics.test.ts

@@ -2,7 +2,11 @@ import { register } from 'prom-client';
 import EventEmitter from 'events';
 import { createTestConfig } from '../test/config/test-config';
 import { REQUEST_TIME, DB_TIME } from './metric-events';
-import { CLIENT_METRICS, FEATURE_UPDATED } from './types/events';
+import {
+    CLIENT_METRICS,
+    CLIENT_REGISTER,
+    FEATURE_UPDATED,
+} from './types/events';
 import { createMetricsMonitor } from './metrics';
 import createStores from '../test/fixtures/store';
 
@@ -32,7 +36,6 @@ beforeAll(() => {
     // @ts-ignore - We don't want a full knex implementation for our tests, it's enough that it actually yields the numbers we want.
     monitor.startMonitoring(config, stores, '4.0.0', eventBus, db);
 });
-
 afterAll(() => {
     monitor.stopMonitoring();
 });
@@ -108,3 +111,37 @@ test('Should collect metrics for database', async () => {
     expect(metrics).toMatch(/db_pool_pending_creates/);
     expect(metrics).toMatch(/db_pool_pending_acquires/);
 });
+
+test('Should collect metrics for client sdk versions', async () => {
+    eventBus.emit(CLIENT_REGISTER, { sdkVersion: 'unleash-client-node:3.2.5' });
+    eventBus.emit(CLIENT_REGISTER, { sdkVersion: 'unleash-client-node:3.2.5' });
+    eventBus.emit(CLIENT_REGISTER, { sdkVersion: 'unleash-client-node:3.2.5' });
+    eventBus.emit(CLIENT_REGISTER, { sdkVersion: 'unleash-client-java:5.0.0' });
+    eventBus.emit(CLIENT_REGISTER, { sdkVersion: 'unleash-client-java:5.0.0' });
+    eventBus.emit(CLIENT_REGISTER, { sdkVersion: 'unleash-client-java:5.0.0' });
+    const metrics = await prometheusRegister.getSingleMetricAsString(
+        'client_sdk_versions',
+    );
+    expect(metrics).toMatch(
+        /client_sdk_versions\{sdk_name="unleash-client-node",sdk_version="3\.2\.5"} 3/,
+    );
+    expect(metrics).toMatch(
+        /client_sdk_versions\{sdk_name="unleash-client-java",sdk_version="5\.0\.0"} 3/,
+    );
+    eventBus.emit(CLIENT_REGISTER, { sdkVersion: 'unleash-client-node:3.2.5' });
+    const newmetrics = await prometheusRegister.getSingleMetricAsString(
+        'client_sdk_versions',
+    );
+    expect(newmetrics).toMatch(
+        /client_sdk_versions\{sdk_name="unleash-client-node",sdk_version="3\.2\.5"} 4/,
+    );
+});
+
+test('Should not collect client sdk version if sdkVersion is of wrong format or non-existent', async () => {
+    eventBus.emit(CLIENT_REGISTER, { sdkVersion: 'unleash-client-rust' });
+    eventBus.emit(CLIENT_REGISTER, {});
+    const metrics = await prometheusRegister.getSingleMetricAsString(
+        'client_sdk_versions',
+    );
+    expect(metrics).not.toMatch(/unleash-client-rust/);
+});

src/lib/metrics.ts

@@ -12,6 +12,7 @@ import {
     FEATURE_STRATEGY_UPDATE,
     FEATURE_UPDATED,
     CLIENT_METRICS,
+    CLIENT_REGISTER,
 } from './types/events';
 import { IUnleashConfig } from './types/option';
 import { IUnleashStores } from './types/stores';
@@ -80,6 +81,12 @@ export default class MetricsMonitor {
             help: 'Number of projects',
         });
 
+        const clientSdkVersionUsage = new client.Counter({
+            name: 'client_sdk_versions',
+            help: 'Which sdk versions are being used',
+            labelNames: ['sdk_name', 'sdk_version'],
+        });
+
         async function collectStaticCounters() {
             let togglesCount: number = 0;
             let usersCount: number;
@@ -157,6 +164,12 @@ export default class MetricsMonitor {
                     .inc(entry[1].no);
             }
         });
+        eventBus.on(CLIENT_REGISTER, (m) => {
+            if (m.sdkVersion && m.sdkVersion.indexOf(':') > -1) {
+                const [sdkName, sdkVersion] = m.sdkVersion.split(':');
+                clientSdkVersionUsage.labels(sdkName, sdkVersion).inc();
+            }
+        });
 
         this.configureDbMetrics(db, eventBus);
     }

src/lib/services/client-metrics/instance-service.test.ts

@@ -2,6 +2,7 @@ import ClientInstanceService from './instance-service';
 import getLogger from '../../../test/fixtures/no-logger';
 import { IClientApp } from '../../types/model';
 import { secondsToMilliseconds } from 'date-fns';
+import FakeEventStore from '../../../test/fixtures/fake-event-store';
 
 /**
  * A utility to wait for any pending promises in the test subject code.
@@ -54,7 +55,7 @@ test('Multiple registrations of same appname and instanceid within same time per
             featureToggleStore: null,
             clientApplicationsStore,
             clientInstanceStore,
-            eventStore: null,
+            eventStore: new FakeEventStore(),
         },
         { getLogger },
     );
@@ -104,7 +105,7 @@ test('Multiple unique clients causes multiple registrations', async () => {
             featureToggleStore: null,
             clientApplicationsStore,
             clientInstanceStore,
-            eventStore: null,
+            eventStore: new FakeEventStore(),
         },
         { getLogger },
     );
@@ -157,7 +158,7 @@ test('Same client registered outside of dedup interval will be registered twice'
             featureToggleStore: null,
             clientApplicationsStore,
             clientInstanceStore,
-            eventStore: null,
+            eventStore: new FakeEventStore(),
         },
         { getLogger },
         bulkInterval,
@@ -210,7 +211,7 @@ test('No registrations during a time period will not call stores', async () => {
             featureToggleStore: null,
             clientApplicationsStore,
             clientInstanceStore,
-            eventStore: null,
+            eventStore: new FakeEventStore(),
         },
         { getLogger },
     );

src/lib/services/client-metrics/instance-service.ts

@@ -1,5 +1,5 @@
 import { applicationSchema } from './schema';
-import { APPLICATION_CREATED } from '../../types/events';
+import { APPLICATION_CREATED, CLIENT_REGISTER } from '../../types/events';
 import { IApplication } from './models';
 import { IUnleashStores } from '../../types/stores';
 import { IUnleashConfig } from '../../types/option';
@@ -111,6 +111,7 @@ export default class ClientInstanceService {
         value.clientIp = clientIp;
         value.createdBy = clientIp;
         this.seenClients[this.clientKey(value)] = value;
+        this.eventStore.emit(CLIENT_REGISTER, value);
     }
 
     async announceUnannounced(): Promise<void> {

src/lib/types/events.ts

@@ -74,6 +74,7 @@ export const SETTING_UPDATED = 'setting-updated';
 export const SETTING_DELETED = 'setting-deleted';
 
 export const CLIENT_METRICS = 'client-metrics';
+export const CLIENT_REGISTER = 'client-register';
 
 export interface IBaseEvent {
     type: string;