7. ReplicaSet

Show minimal ReplicaSet definition

$ tee files/kuard-rs.yaml << EOF
apiVersion: extensions/v1beta1
kind: ReplicaSet
metadata:
  name: kuard
spec:
  replicas: 1
  selector:
    matchLabels:
      app: kuard
      version: "2"
  template:
    metadata:
      labels:
        app: kuard
        version: "2"
    spec:
      containers:
        - name: kuard
          image: "gcr.io/kuar-demo/kuard-amd64:2"
EOF

Create ReplicaSet

$ kubectl apply -f files/kuard-rs.yaml

Check pods

$ kubectl get pods

Check ReplicaSet details

$ kubectl describe rs kuard

The pods have the same labels as ReplicaSet

$ kubectl get pods -l app=kuard,version=2 --show-labels

Check if pod is part of ReplicaSet

$ kubectl get pods -l app=kuard,version=2 -o json | jq ".items[].metadata"

Scale up ReplicaSet

$ kubectl scale replicasets kuard --replicas=4

New pods are beeing created

$ kubectl get pods -l app=kuard --show-labels

Delete ReplicaSet

$ kubectl delete rs kuard