add prometheus integration for node and netcore

Author: marcel-dempers

prometheus-monitoring/dashboard.json

@@ -6,28 +6,28 @@ services:
     container_name: go-application
     image: go-application
     ports:
-      - "80:80"
+      - "80:5000"
   python-application:
     build:
       context: ./python-application
     container_name: python-application
     image: python-application
     ports:
-      - "81:80"
+      - "81:5000"
   dotnet-application:
     build:
       context: ./dotnet-application
     container_name: dotnet-application
     image: dotnet-application
     ports:
-      - "82:80"
+      - "82:5000"
   nodejs-application:
     build:
       context: ./nodejs-application
     container_name: nodejs-application
     image: nodejs-application
     ports:
-      - "83:80"
+      - "83:5000"
   prometheus:
     container_name: prometheus-svc
     image: prom/prometheus

prometheus-monitoring/docker-compose.yaml

@@ -1,16 +1,34 @@
 using System;
+using System.Diagnostics;
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.AspNetCore.Mvc.RazorPages;
-
+using Prometheus;
 namespace work.Pages
 {
     public class IndexModel : PageModel
     {
+        private static readonly Counter ProcessedJobCount = Metrics
+	.CreateCounter("dotnet_request_operations_total", "The total number of processed requests");
         public void OnGet()
         {
+            var sw = Stopwatch.StartNew();
+
+            sw.Stop();
+            ProcessedJobCount.Inc();
+            var histogram =
+            Metrics
+                .CreateHistogram(
+                    "dotnet_request_duration_seconds",
+                    "Histogram for the duration in seconds.",
+                    new[] { 0.02, 0.05, 0.1, 0.15, 0.2, 0.5, 0.8, 1 },
+                    "GET",
+                    "/");
+
+        histogram
+            .Observe(sw.Elapsed.TotalSeconds);
 
         }
     }

prometheus-monitoring/dotnet-application/src/Pages/Index.cshtml.cs

@@ -9,6 +9,7 @@
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
+using Prometheus;
 
 namespace work
 {
@@ -52,7 +53,7 @@ public void Configure(IApplicationBuilder app, IHostingEnvironment env)
             app.UseHttpsRedirection();
             app.UseStaticFiles();
             app.UseCookiePolicy();
-
+            app.UseMetricServer();
             app.UseMvc();
         }
     }

prometheus-monitoring/dotnet-application/src/Startup.cs

@@ -10,6 +10,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.AspNetCore.App"/>
+    <PackageReference Include="prometheus-net.AspNetCore"  Version="3.1.4"/>
     <PackageReference Include="Microsoft.AspNetCore.Razor.Design" Version="2.2.0" PrivateAssets="All" />
   </ItemGroup>
 

prometheus-monitoring/dotnet-application/src/work.csproj

@@ -25,6 +25,6 @@ RUN apk update && apk upgrade && \
 WORKDIR /go/src/app
 COPY --from=builder /go/src/app/myapp /go/src/app/myapp
 
-EXPOSE 80
+EXPOSE 5000
 
 CMD ["./myapp"]

prometheus-monitoring/go-application/dockerfile

@@ -46,6 +46,6 @@ func main() {
 	})
 
 	http.Handle("/metrics", promhttp.Handler())
-	http.ListenAndServe(":80", nil)
+	http.ListenAndServe(":5000", nil)
 
 }

prometheus-monitoring/go-application/main.go

@@ -8,6 +8,7 @@
     "start": "node server.js"
   },
   "dependencies": {
-    "express": "^4.16.1"
+    "express": "^4.16.1",
+    "prom-client" : "11.5.3"
   }
 }

prometheus-monitoring/nodejs-application/src/package.json

@@ -7,10 +7,46 @@ const PORT = 5000;
 const HOST = '0.0.0.0';
 
 // App
+const client = require('prom-client');
+const collectDefaultMetrics = client.collectDefaultMetrics;
+// Probe every 5th second.
+collectDefaultMetrics({ timeout: 5000 });
+
+const counter = new client.Counter({
+  name: 'node_request_operations_total',
+  help: 'The total number of processed requests'
+});
+
+const histogram = new client.Histogram({
+  name: 'node_request_duration_seconds',
+  help: 'Histogram for the duration in seconds.',
+  buckets: [1, 2, 5, 6, 10]
+});
+
 const app = express();
 app.get('/', (req, res) => {
+
+  //Simulate a sleep
+  var start = new Date()
+  var simulateTime = 1000
+
+  setTimeout(function(argument) {
+    // execution time simulated with setTimeout function
+    var end = new Date() - start
+    histogram.observe(end / 1000); //convert to seconds
+  }, simulateTime)
+
+  counter.inc();
+  
   res.send('Hello world\n');
 });
 
+
+// Metrics endpoint
+app.get('/metrics', (req, res) => {
+  res.set('Content-Type', client.register.contentType)
+  res.end(client.register.metrics())
+})
+
 app.listen(PORT, HOST);
 console.log(`Running on http://${HOST}:${PORT}`);

prometheus-monitoring/nodejs-application/src/server.js

@@ -5,4 +5,4 @@ scrape_configs:
 - job_name: my-application
   honor_labels: true
   static_configs:
-  - targets: ['go-application','python-application','dotnet-application','nodejs-application']
+  - targets: ['go-application:5000','python-application:5000','dotnet-application:5000','nodejs-application:5000']