feat: add prometheus (#299)

Signed-off-by: OMPRAKASH MISHRA <[email protected]>

api/package.json

@@ -18,6 +18,7 @@
     "mongoose": "^7.5.0",
     "morgan": "^1.10.0",
     "nocache": "^4.0.0",
+    "prom-client": "^15.1.0",
     "winston": "^3.8.2"
   },
   "devDependencies": {

api/src/app.js

@@ -8,9 +8,13 @@ const app = express();
 const apiRouter = express.Router();
 const pubcodeRouter = require("./routes/pubcode-router");
 const log = require("./logger");
+const prom = require('prom-client');
+const register = new prom.Registry();
+prom.collectDefaultMetrics({ register });
+
 const rateLimit = require('express-rate-limit');
 const limiter = rateLimit({
-  windowMs: 1 * 60 * 1000, // 1 minute
+  windowMs: 60 * 1000, // 1 minute
   max: 100, // Limit each IP to 100 requests per `window` (here, per 1 minutes)
   standardHeaders: true, // Return rate limit info in the `RateLimit-*` headers
   legacyHeaders: false, // Disable the `X-RateLimit-*` headers
@@ -25,7 +29,10 @@ app.use(limiter);
 app.use(cors());
 app.use(helmet());
 app.use(nocache());
-
+app.get('/metrics', async (_req, res) => {
+  const appMetrics = await register.metrics();
+  res.end(appMetrics);
+});
 //tells the app to use json as means of transporting data
 app.use(bodyParser.json({ limit: "50mb", extended: true }));
 app.use(bodyParser.urlencoded({

charts/pubcode/values.yaml

@@ -89,6 +89,10 @@ api:
     enabled: true
     host: "{{ .Release.Name }}-api.{{ .Values.global.domain }}"
     targetPort: http # look at line#164 refer to the name.
+  podAnnotations:
+    prometheus.io/scrape: "true"
+    prometheus.io/port: "3000"
+    prometheus.io/path: "/metrics"
 
 frontend:
   enabled: true
@@ -160,6 +164,10 @@ frontend:
     enabled: true
     host: "{{ .Release.Name }}.{{ .Values.global.domain }}"
     targetPort: http # look at line#164 refer to the name.
+  podAnnotations:
+    prometheus.io/scrape: "true"
+    prometheus.io/port: "3002"
+    prometheus.io/path: "/metrics"
 
 database:
   enabled: true

frontend/Caddyfile

@@ -1,6 +1,9 @@
 {
 	auto_https off
-	admin off
+	  admin 0.0.0.0:3002
+    servers {
+      metrics
+    }
 }
 :3000 {
 	log {