From 90c310396a196e49f13cdd65f118fd7014d529cf Mon Sep 17 00:00:00 2001
From: fchinembiri <fchinembiri24@gmail.com>
Date: Tue, 28 Jul 2026 10:11:33 +0200
Subject: [PATCH] feat(metrics): expose Prometheus metrics endpoint on /metrics
 and /api/metrics across all nextgen servers

---
 apps/nextgen/server/package-lock.json | 38 +++++++++++++++++++++++++++
 apps/nextgen/server/package.json      |  1 +
 apps/nextgen/server/src/index.js      | 33 +++++++++++++++++++++++
 k8s/nextgen/manual-deployments.yaml   |  4 +--
 4 files changed, 74 insertions(+), 2 deletions(-)

diff --git a/apps/nextgen/server/package-lock.json b/apps/nextgen/server/package-lock.json
index bdfc787..8f940e8 100644
--- a/apps/nextgen/server/package-lock.json
+++ b/apps/nextgen/server/package-lock.json
@@ -15,12 +15,22 @@
         "express": "^4.18.2",
         "jsonwebtoken": "^9.0.2",
         "multer": "^1.4.5-lts.1",
+        "prom-client": "^15.1.3",
         "uuid": "^9.0.1"
       },
       "devDependencies": {
         "nodemon": "^3.0.3"
       }
     },
+    "node_modules/@opentelemetry/api": {
+      "version": "1.9.1",
+      "resolved": "https://registry.npmjs.org/@opentelemetry/api/-/api-1.9.1.tgz",
+      "integrity": "sha512-gLyJlPHPZYdAk1JENA9LeHejZe1Ti77/pTeFm/nMXmQH/HFZlcS/O2XJB+L8fkbrNSqhdtlvjBVjxwUYanNH5Q==",
+      "license": "Apache-2.0",
+      "engines": {
+        "node": ">=8.0.0"
+      }
+    },
     "node_modules/@supabase/auth-js": {
       "version": "2.107.0",
       "resolved": "https://registry.npmjs.org/@supabase/auth-js/-/auth-js-2.107.0.tgz",
@@ -216,6 +226,12 @@
         "file-uri-to-path": "1.0.0"
       }
     },
+    "node_modules/bintrees": {
+      "version": "1.0.2",
+      "resolved": "https://registry.npmjs.org/bintrees/-/bintrees-1.0.2.tgz",
+      "integrity": "sha512-VOMgTMwjAaUG580SXn3LacVgjurrbMme7ZZNYGSSV7mmtY6QQRh0Eg3pwIcntQ77DErK1L0NxkbetjcoXzVwKw==",
+      "license": "MIT"
+    },
     "node_modules/bl": {
       "version": "4.1.0",
       "resolved": "https://registry.npmjs.org/bl/-/bl-4.1.0.tgz",
@@ -1451,6 +1467,19 @@
       "integrity": "sha512-3ouUOpQhtgrbOa17J7+uxOTpITYWaGP7/AhoR3+A+/1e9skrzelGi/dXzEYyvbxubEF6Wn2ypscTKiKJFFn1ag==",
       "license": "MIT"
     },
+    "node_modules/prom-client": {
+      "version": "15.1.3",
+      "resolved": "https://registry.npmjs.org/prom-client/-/prom-client-15.1.3.tgz",
+      "integrity": "sha512-6ZiOBfCywsD4k1BN9IX0uZhF+tJkV8q8llP64G5Hajs4JOeVLPCwpPVcpXy3BwYiUGgyJzsJJQeOIv7+hDSq8g==",
+      "license": "Apache-2.0",
+      "dependencies": {
+        "@opentelemetry/api": "^1.4.0",
+        "tdigest": "^0.1.1"
+      },
+      "engines": {
+        "node": "^16 || ^18 || >=20"
+      }
+    },
     "node_modules/proxy-addr": {
       "version": "2.0.7",
       "resolved": "https://registry.npmjs.org/proxy-addr/-/proxy-addr-2.0.7.tgz",
@@ -1884,6 +1913,15 @@
         "node": ">= 6"
       }
     },
+    "node_modules/tdigest": {
+      "version": "0.1.2",
+      "resolved": "https://registry.npmjs.org/tdigest/-/tdigest-0.1.2.tgz",
+      "integrity": "sha512-+G0LLgjjo9BZX2MfdvPfH+MKLCrxlXSYec5DaPYP1fe6Iyhf0/fSmJ0bFiZ1F8BT6cGXl2LpltQptzjXKWEkKA==",
+      "license": "MIT",
+      "dependencies": {
+        "bintrees": "1.0.2"
+      }
+    },
     "node_modules/to-regex-range": {
       "version": "5.0.1",
       "resolved": "https://registry.npmjs.org/to-regex-range/-/to-regex-range-5.0.1.tgz",
diff --git a/apps/nextgen/server/package.json b/apps/nextgen/server/package.json
index 6bc0d0f..3ac98ef 100644
--- a/apps/nextgen/server/package.json
+++ b/apps/nextgen/server/package.json
@@ -16,6 +16,7 @@
     "express": "^4.18.2",
     "jsonwebtoken": "^9.0.2",
     "multer": "^1.4.5-lts.1",
+    "prom-client": "^15.1.3",
     "uuid": "^9.0.1"
   },
   "devDependencies": {
diff --git a/apps/nextgen/server/src/index.js b/apps/nextgen/server/src/index.js
index d9185e9..79178a3 100644
--- a/apps/nextgen/server/src/index.js
+++ b/apps/nextgen/server/src/index.js
@@ -38,6 +38,39 @@ getSyncEngine();
 
 // Middleware
 app.use(cors());
+
+// Prometheus Metrics Setup
+const client = require('prom-client');
+const register = new client.Registry();
+client.collectDefaultMetrics({ register });
+
+const httpRequestDurationSeconds = new client.Histogram({
+  name: 'http_request_duration_seconds',
+  help: 'Duration of HTTP requests in seconds',
+  labelNames: ['method', 'route', 'code'],
+  buckets: [0.05, 0.1, 0.3, 0.5, 1, 2, 5]
+});
+register.registerMetric(httpRequestDurationSeconds);
+
+app.use((req, res, next) => {
+  const start = Date.now();
+  res.on('finish', () => {
+    const duration = (Date.now() - start) / 1000;
+    httpRequestDurationSeconds
+      .labels(req.method, req.route ? req.route.path : req.path, res.statusCode)
+      .observe(duration);
+  });
+  next();
+});
+
+app.get(['/metrics', '/api/metrics'], async (req, res) => {
+  try {
+    res.set('Content-Type', register.contentType);
+    res.end(await register.metrics());
+  } catch (err) {
+    res.status(500).end(err);
+  }
+});
 app.use(express.json());
 app.use('/uploads', express.static(path.join(__dirname, '../uploads')));
 
diff --git a/k8s/nextgen/manual-deployments.yaml b/k8s/nextgen/manual-deployments.yaml
index 0013692..d393686 100644
--- a/k8s/nextgen/manual-deployments.yaml
+++ b/k8s/nextgen/manual-deployments.yaml
@@ -98,7 +98,7 @@ spec:
     - name: http
       protocol: TCP
       port: 80
-      targetPort: http
+      targetPort: 3001
 ---
 apiVersion: networking.k8s.io/v1
 kind: Ingress
@@ -140,7 +140,7 @@ spec:
     - name: http
       protocol: TCP
       port: 80
-      targetPort: http
+      targetPort: 3001
 ---
 apiVersion: networking.k8s.io/v1
 kind: Ingress