In Kubernetes, how to set pods' names when using replication controllers?

Question

I have a simple replication controller yaml file which looks like this:

apiVersion: v1
kind: ReplicationController
metadata:
  name: nginx
spec:
  replicas: 3
           


        

Answer 1

You should be using statefulset instead of replication controllers. Moreover, replication controllers are replaced with ReplicaSets.

StatefulSet Pods have a unique identity that is comprised of an ordinal. For a StatefulSet with N replicas, each Pod in the StatefulSet will be assigned an integer ordinal, from 0 up through N-1, that is unique over the Set. Each Pod in a StatefulSet derives its hostname from the name of the StatefulSet and the ordinal of the Pod.

StatefulSets matches your requirements and hence use it in your deployment.

Try the deployment files below:

apiVersion: v1
kind: Service
metadata:
  name: nginx
  labels:
    app: nginx
spec:
  ports:
  - port: 80
    name: web
  clusterIP: None
  selector:
    app: nginx
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: web
spec:
  selector:
    matchLabels:
      app: nginx # has to match .spec.template.metadata.labels
  serviceName: "nginx"
  replicas: 3 # by default is 1
  template:
    metadata:
      labels:
        app: nginx # has to match .spec.selector.matchLabels
    spec:
      terminationGracePeriodSeconds: 10
      containers:
      - name: nginx
        image: k8s.gcr.io/nginx-slim:0.8
        ports:
        - containerPort: 80
          name: web
        volumeMounts:
        - name: www
          mountPath: /usr/share/nginx/html
      volumes:
      - name: www
        emptyDir: