chore: added support for stats calculation middleware on the endpoint…

… customTransform

src/middlewares/stats.ts

@@ -0,0 +1,15 @@
+import { Context, Next } from 'koa';
+
+export class StatsMiddleware {
+  private static instanceID: string = process.env.INSTANCE_ID || 'unknown';
+
+  private static workerID: string = process.env.WORKER_ID || 'unknown';
+
+  public static async executionStats(ctx: Context, next: Next) {
+    const start = Date.now();
+    await next();
+    const ms = Date.now() - start;
+    ctx.set('X-Response-Time', `${ms}ms`);
+    ctx.set('X-Instance-ID', `${StatsMiddleware.instanceID}/${StatsMiddleware.workerID}`);
+  }
+}

src/routes/userTransform.ts

@@ -1,7 +1,9 @@
 import Router from '@koa/router';
-import { RouteActivationMiddleware } from '../middlewares/routeActivation';
-import { FeatureFlagMiddleware } from '../middlewares/featureFlag';
+import { Context } from 'koa';
 import { UserTransformController } from '../controllers/userTransform';
+import { FeatureFlagMiddleware } from '../middlewares/featureFlag';
+import { RouteActivationMiddleware } from '../middlewares/routeActivation';
+import { StatsMiddleware } from '../middlewares/stats';
 
 const router = new Router();
 
@@ -15,6 +17,7 @@ router.post(
   '/customTransform',
   RouteActivationMiddleware.isUserTransformRouteActive,
   FeatureFlagMiddleware.handle,
+  StatsMiddleware.executionStats,
   UserTransformController.transform,
 );
 router.post(

src/util/cluster.js

@@ -28,6 +28,8 @@ async function shutdownWorkers() {
 }
 
 function start(port, app, metricsApp) {
+  console.log(numWorkers);
+
   if (cluster.isMaster) {
     logger.info(`Master (pid: ${process.pid}) has started`);
 
@@ -44,7 +46,9 @@ function start(port, app, metricsApp) {
 
     // Fork workers.
     for (let i = 0; i < numWorkers; i += 1) {
-      cluster.fork();
+      cluster.fork({
+        WORKER_ID: `worker-${i + 1}`,
+      });
     }
 
     cluster.on('online', (worker) => {