task-022-labels-and-selectors

• How many pods have the following labels du=finanace in default namespace

$ kubectl get pods -l bu=finance

• How many objects have label env=prod including PODs, ReplicaSets and any other objects?

$ kubectl get all -l env=prod --no-headers | wc -l

• Identify the POD which is part of the prod environment, the finance BU and of frontend tier?

$ kubectl get pod -l env=prod,bu=finance,tier=frontend

• Note: That the labels and selectors cannot have different values

$ cat replicaset-definition-1.yaml | grep -B 2 tier
  selector:
    matchLabels:
      tier: frontend
--
    metadata:
      labels:
        tier: nginx
$ kubectl apply -f replicaset-definition-1.yaml
The ReplicaSet "replicaset-1" is invalid: spec.template.metadata.labels: Invalid value: map[string]string{"tier":"nginx"}: `selector` does not match template `labels`

$ cat replicaset-definition-1.yaml | grep -B 2 tier
  selector:
    matchLabels:
      tier: frontend
--
    metadata:
      labels:
        tier: frontend

$ kubectl apply -f replicaset-definition-1.yaml
replicaset.apps/replicaset-1 created