Server-Timing

.env.example

@@ -42,5 +42,5 @@ SMS_SENDER=
 # SMS_TRANSPORT=soap
 # SMS_DOMAIN=0098
 
-# Minimum minutes before a booking can be scheduled (default 60)
-BOOKING_MIN_LEAD_MINUTES=60
+# Optional: log Server-Timing to PM2 stdout (total;dur=… per request)
+# LOG_SERVER_TIMING=true

src/common/interceptors/server-timing.interceptor.ts

@@ -0,0 +1,42 @@
+import {
+  CallHandler,
+  ExecutionContext,
+  Injectable,
+  Logger,
+  NestInterceptor,
+} from '@nestjs/common';
+import { Observable } from 'rxjs';
+import { finalize } from 'rxjs/operators';
+
+@Injectable()
+export class ServerTimingInterceptor implements NestInterceptor {
+  private readonly logger = new Logger(ServerTimingInterceptor.name);
+
+  intercept(context: ExecutionContext, next: CallHandler): Observable<unknown> {
+    const http = context.switchToHttp();
+    const response = http.getResponse<{
+      setHeader(name: string, value: string): void;
+      getHeader(name: string): string | number | string[] | undefined;
+    }>();
+    const request = http.getRequest<{ method?: string; url?: string }>();
+    const start = performance.now();
+
+    return next.handle().pipe(
+      finalize(() => {
+        const dur = Math.max(0, Math.round(performance.now() - start));
+        const existing = response.getHeader('Server-Timing');
+        const total = `total;dur=${dur}`;
+        response.setHeader(
+          'Server-Timing',
+          existing ? `${String(existing)}, ${total}` : total,
+        );
+        if (process.env.LOG_SERVER_TIMING === 'true') {
+          const route = request.url ?? '';
+          this.logger.log(
+            `${request.method ?? '?'} ${route} total;dur=${dur}`,
+          );
+        }
+      }),
+    );
+  }
+}

src/main.ts

@@ -5,17 +5,28 @@ import { NestExpressApplication } from '@nestjs/platform-express';
 import { DocumentBuilder, SwaggerModule } from '@nestjs/swagger';
 import { join } from 'path';
 import { TypeOrmExceptionFilter } from './common/filters/typeorm-exception.filter';
+import { ServerTimingInterceptor } from './common/interceptors/server-timing.interceptor';
 import { AppModule } from './app.module';
 
+const CORS_EXPOSE_HEADERS = ['Server-Timing'];
+
 function configureCors(app: Awaited<ReturnType<typeof NestFactory.create>>) {
   const raw = process.env.CORS_ORIGINS?.trim();
   if (raw) {
     const origins = raw.split(',').map((o) => o.trim()).filter(Boolean);
-    app.enableCors({ origin: origins, credentials: true });
+    app.enableCors({
+      origin: origins,
+      credentials: true,
+      exposedHeaders: CORS_EXPOSE_HEADERS,
+    });
     return;
   }
   if (process.env.NODE_ENV !== 'production') {
-    app.enableCors({ origin: true, credentials: true });
+    app.enableCors({
+      origin: true,
+      credentials: true,
+      exposedHeaders: CORS_EXPOSE_HEADERS,
+    });
   }
 }
 
@@ -32,6 +43,7 @@ async function bootstrap() {
     }),
   );
   app.useGlobalFilters(new TypeOrmExceptionFilter());
+  app.useGlobalInterceptors(new ServerTimingInterceptor());
 
   const swaggerConfig = new DocumentBuilder()
     .setTitle('Montime API')