Kubernetes Cookbook - Second Edition

Pod-to-Service communication

In the ordinary course of events, Pods can be stopped accidentally. Then, the IP of the Pod can be changed. When we expose the port for a Pod or a Deployment, we create a Kubernetes Service that acts as a proxy or a load balancer. Kubernetes would create a virtual IP, which receives the request from clients and proxies the traffic to the Pods in a service. Let's review how to do this:

1. First, we would create a Deployment and expose it to a Service:

$ cat nodeport-deployment.yamlapiVersion: apps/v1kind: Deploymentmetadata:  name: nodeport-deployspec:  replicas: 2  selector:    matchLabels:      app: nginx  template:    metadata:      labels:        app: nginx    spec:      containers:      - name: my-nginx        image: nginx---apiVersion: v1kind: Service ...