feat: 完善服务监控与下游重投

api/src/metrics/metrics.interceptor.ts

@@ -0,0 +1,24 @@
+import { CallHandler, ExecutionContext, Injectable, NestInterceptor } from '@nestjs/common';
+import type { Observable } from 'rxjs';
+import { finalize } from 'rxjs/operators';
+import { MetricsService } from './metrics.service';
+
+type RequestLike = { method?: string; baseUrl?: string; route?: { path?: string } };
+type ResponseLike = { statusCode?: number };
+
+@Injectable()
+export class MetricsInterceptor implements NestInterceptor {
+  constructor(private readonly metrics: MetricsService) {}
+
+  intercept(context: ExecutionContext, next: CallHandler): Observable<unknown> {
+    if (context.getType() !== 'http') return next.handle();
+    const http = context.switchToHttp();
+    const request = http.getRequest<RequestLike>();
+    const response = http.getResponse<ResponseLike>();
+    const startedAt = this.metrics.beginRequest();
+    return next.handle().pipe(finalize(() => {
+      const route = `${request.baseUrl ?? ''}${request.route?.path ?? '/unmatched'}`;
+      this.metrics.finishRequest(startedAt, request.method ?? 'UNKNOWN', route, response.statusCode ?? 500);
+    }));
+  }
+}