Trying out a sample Deployment

Let’s see how we can do the following:

• Deploy a simple web server based on NGINX in our Kubernetes cluster
• Apply some changes to the Deployment:
  • Change the current state by deleting the Pod and verify that the ReplicaSet creates a new one
  • Change the desired state by scaling the web server to three Pods and verify that the ReplicaSet fills the gap by starting up two new Pods
• Route external traffic to the web server using a Service with a node port

First, create a namespace, first-attempts, and update the kubectl context to use this namespace by default:

kubectl create namespace first-attempts
kubectl config set-context $(kubectl config current-context) --namespace=first-attempts

We can now create a Deployment of NGINX in the namespace using the kubernetes/first-attempts/nginx-deployment.yaml file. This file looks as follows:

apiVersion: apps/v1
kind: Deployment
metadata...