Kubernetes Cookbook - Second Edition

Linking Deployment to ReplicaSet using the set-based selector

Deployment supports not only the equality-based selector, but also the set-based selector, to specify ReplicaSet. To do that, you can write spec.selector.matchExpressions[] to specify the key and in/notin operator. For example, if you want to specify project in (poc), environment in (staging), tier notn (backend,cache), then matchExpressions would be as follows:

$ cat deploy_set_selector.yaml apiVersion: apps/v1kind: Deploymentmetadata:  name: my-nginxspec:  replicas: 3  selector:    matchExpressions:      - {key: project, operator: In, values: [poc]}      - {key: environment, operator: In, values: [staging]}      - {key: tier, operator: NotIn, values: [backend,cache]}  template:    metadata:      labels: