feat: resolve useragent source and add as source label to metrics (#7883)

src/lib/metric-events.ts

@@ -30,6 +30,7 @@ type MetricEvent =
 type RequestOriginEventPayload = {
     type: 'UI' | 'API';
     method: Request['method'];
+    source?: string;
 };
 
 type MetricEventPayloads = {

src/lib/metrics.ts

@@ -350,7 +350,7 @@ export default class MetricsMonitor {
         const requestOriginCounter = createCounter({
             name: 'request_origin_counter',
             help: 'Number of authenticated requests, including origin information.',
-            labelNames: ['type', 'method'],
+            labelNames: ['type', 'method', 'source'],
         });
 
         const resourceLimit = createGauge({
@@ -715,9 +715,9 @@ export default class MetricsMonitor {
         events.onMetricEvent(
             eventBus,
             events.REQUEST_ORIGIN,
-            ({ type, method }) => {
+            ({ type, method, source }) => {
                 if (flagResolver.isEnabled('originMiddleware')) {
-                    requestOriginCounter.increment({ type, method });
+                    requestOriginCounter.increment({ type, method, source });
                 }
             },
         );

src/lib/middleware/integration-headers.test.ts

@@ -0,0 +1,29 @@
+import { determineIntegrationSource } from './integration-headers';
+
+test('resolves known user agents to source labels', () => {
+    expect(determineIntegrationSource('axios/0.27.2')).toBe('Axios');
+    expect(determineIntegrationSource('axios/1.4.0')).toBe('Axios');
+    expect(determineIntegrationSource('curl/8.6.0')).toBe('Curl');
+    expect(determineIntegrationSource('node-fetch/1.0.0')).toBe('Node');
+    expect(determineIntegrationSource('node')).toBe('Node');
+    expect(determineIntegrationSource('python-requests/2.31.0')).toBe('Python');
+    expect(determineIntegrationSource('Terraform-Provider-Unleash/1.1.1')).toBe(
+        'TerraformUnleash',
+    );
+    expect(determineIntegrationSource('Jira-Cloud-Unleash')).toBe(
+        'JiraCloudUnleash',
+    );
+    expect(determineIntegrationSource('OpenAPI-Generator/1.0.0/go')).toBe(
+        'OpenAPIGO',
+    );
+    expect(
+        determineIntegrationSource('Apache-HttpClient/4.5.13 (Java/11.0.22)'),
+    ).toBe('Java');
+    expect(determineIntegrationSource('Go-http-client/1.1')).toBe('Go');
+    expect(
+        determineIntegrationSource(
+            'rest-client/2.0.2 (linux-gnu x86_64) ruby/2.1.7p400',
+        ),
+    ).toBe('RestClientRuby');
+    expect(determineIntegrationSource('No-http-client')).toBe('Other');
+});

src/lib/middleware/integration-headers.ts

@@ -0,0 +1,34 @@
+import type { Request } from 'express';
+
+const ORIGIN = 'origin';
+const httpMatcher = /^https?:\/\//;
+const userAgentMatches = [
+    { label: 'Axios', matcher: /^axios/ },
+    { label: 'Curl', matcher: /^curl/ },
+    { label: 'Go', matcher: /^Go-http-client/ },
+    { label: 'Python', matcher: /^python-requests/ },
+    { label: 'Node', matcher: /^node/ },
+    { label: 'Java', matcher: /^Apache-HttpClient.*Java/ },
+    { label: 'JiraCloudUnleash', matcher: /^Jira-Cloud-Unleash/ },
+    { label: 'TerraformUnleash', matcher: /^Terraform-Provider-Unleash/ },
+    { label: 'OpenAPIGO', matcher: /^OpenAPI-Generator\/.*\/go/ },
+    { label: 'RestClientRuby', matcher: /^rest-client\/.*ruby/ },
+];
+
+export const getFilteredOrigin = (request: Request): string | undefined => {
+    const origin = request.headers[ORIGIN];
+    if (origin && httpMatcher.test(origin)) {
+        return origin;
+    }
+
+    return undefined;
+};
+
+export const determineIntegrationSource = (
+    userAgent: string,
+): string | undefined => {
+    return (
+        userAgentMatches.find((candidate) => candidate.matcher.test(userAgent))
+            ?.label ?? 'Other'
+    );
+};

src/lib/middleware/origin-middleware.test.ts

@@ -69,6 +69,7 @@ describe('originMiddleware', () => {
         expect(eventBus.emit).toHaveBeenCalledWith(REQUEST_ORIGIN, {
             type: 'API',
             method: req.method,
+            source: 'Other',
         });
     });
 
@@ -83,6 +84,7 @@ describe('originMiddleware', () => {
         expect(loggerMock.info).toHaveBeenCalledWith('API request', {
             method: req.method,
             userAgent: TEST_USER_AGENT,
+            origin: undefined,
         });
     });
 });

src/lib/middleware/origin-middleware.ts

@@ -1,6 +1,10 @@
 import type { Request, Response, NextFunction } from 'express';
 import type { IUnleashConfig } from '../types';
 import { REQUEST_ORIGIN, emitMetricEvent } from '../metric-events';
+import {
+    determineIntegrationSource,
+    getFilteredOrigin,
+} from './integration-headers';
 
 export const originMiddleware = ({
     getLogger,
@@ -23,13 +27,19 @@ export const originMiddleware = ({
                 method: req.method,
             });
         } else {
+            const userAgent = req.headers['user-agent'];
+            const uaLabel = userAgent
+                ? determineIntegrationSource(userAgent)
+                : 'Other';
             logger.info('API request', {
                 method: req.method,
                 userAgent: req.headers['user-agent'],
+                origin: getFilteredOrigin(req),
             });
             emitMetricEvent(eventBus, REQUEST_ORIGIN, {
                 type: 'API',
                 method: req.method,
+                source: uaLabel,
             });
         }