Prometheus2 (#247)

* Update .travis.yml

* Update .travis.yml

* Get Connections & Prometheus changes

* removed prometheus server

Co-authored-by: Michael McKay <mckaymic@us.ibm.com>

app/index.js

@@ -28,8 +28,13 @@ const port = 3333;
 
 const swaggerUi = require('swagger-ui-express');
 const swaggerDocument = require('./swagger.json');
-
 const apollo = require('./apollo');
+
+const promClient = require('prom-client');
+const collectDefaultMetrics = promClient.collectDefaultMetrics;
+collectDefaultMetrics({ timeout: 5000 });    //Collect all default metrics
+const connections = new promClient.Gauge({ name: 'razee_server_connections_count', help: 'Razee server request count' });
+
 app.use('/api-docs', swaggerUi.serve, swaggerUi.setup(swaggerDocument));
 
 router.use(ebl(getBunyanConfig('razeedash-api')));
@@ -61,11 +66,17 @@ app.use(function errorHandler(err, req, res, next) {
   next();
 });
 
+app.get('/metrics', function (request, response) {
+  response.writeHead(200, {'Content-Type': promClient.register.contentType});
+  response.end(promClient.register.metrics());
+});
+
 const server = http.createServer(app);
 
 server.on('ready', onReady);
 server.on('error', onError);
 server.on('listening', onListening);
+server.on('connection', onConnection);
 
 require('./subs/index')(server);
 
@@ -111,3 +122,11 @@ function onError(error) {
   }
 
 }
+
+// emitted when new client connects
+function onConnection(){
+  server.getConnections(function(error,count){
+    //console.log('Number of concurrent connections to the server : ' + count);
+    connections.set(count);
+  });
+}

package.json

@@ -72,7 +72,8 @@
     "swagger-ui-express": "^4.1.4",
     "uuid": "^7.0.3",
     "validator": "^12.2.0",
-    "ws": "^7.2.3"
+    "ws": "^7.2.3",
+    "prom-client": "^12.0.0"
   },
   "devDependencies": {
     "axios": "^0.19.2",