ClusterIP is the default Service type. It exposes the Service on a cluster-internal IP. Pods in the cluster could reach the Service via the IP address, environment variables, or DNS. In the following example, we'll learn how to use both native Service environment variables and DNS to access the pods behind Services in the cluster.
Before starting a Service, we'd like to create two sets of RS with different version labels, as follows:
// create RS 1 with nginx 1.12.0 version# cat 3-2-3_rs1.yamlapiVersion: apps/v1kind: ReplicaSetmetadata: name: nginx-1.12spec: replicas: 2 selector: matchLabels: project: chapter3 service: web version: "0.1" template: metadata: name: nginx labels: project: chapter3 service: web version: "0.1" spec: ...