Before we move on, let's take a look at these three concepts in action. Kubernetes ships with a number of examples installed, but we'll create a new example from scratch to illustrate some of the concepts.
We already created a pod definition file but, as you learned, there are many advantages to running our pods via replication controllers. Again, using the book-examples/02_example folder we made earlier, we'll create some definition files and start a cluster of Node.js servers using a replication controller approach. Additionally, we'll add a public face to it with a load-balanced service.
Use your favorite editor to create the following file and name it as nodejs-controller.yaml:
apiVersion: v1
kind: ReplicationController
metadata:
name: node-js
labels:
name: node-js
spec:
replicas: 3
selector:
name: node...