Add instrumentation

Author: IvanUkhov

README.md

@@ -1,6 +1,6 @@
 # Container Well-being
 
-The package provides standard checks and probes for containers on Kubernetes.
+The package provides probes and metrics for containers on Kubernetes.
 
 ## Installation
 
@@ -11,7 +11,7 @@ npm install @thetypefounders/container-well-being --save
 ## Usage
 
 ```javascript
-import { Status } from '@thetypefounders/container-well-being';
+import { Instrumentation, Status } from '@thetypefounders/container-well-being';
 import express from 'express';
 
 const status = new Status({
@@ -25,8 +25,27 @@ const status = new Status({
   graceAfterSeconds: 80,
 });
 
+const instrumentation = new Instrumentation({
+  // The host to bind to.
+  host: '0.0.0.0',
+  // The port to listen to.
+  port: 9090,
+  // Whether to collect default metrics.
+  defaultMetrics: true,
+});
+
+const counter = Instrumentation.Counter({
+  name: 'example_counter',
+  help: 'Example of a counter',
+});
+
 const app = express();
 
+app.get('/', (request, response) => {
+  counter.inc();
+  response.status(204).send();
+});
+
 const server = app
   .listen(8080, '0.0.0.0', () => {
     status.start();