Kubernetes selectors

• https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/
• https://kubernetes.io/docs/concepts/overview/working-with-objects/field-selectors/

• podSelector
• labelSelector
• spec.selector

• kind: Deployment, kind: Service (Services without selectors)
• kind: PodDisruptionBudget

Examples

• kubectl get pods --selector=app=YOUR_APP

• kubectl get pods --selector=app=YOUR_APP -o=jsonpath='{.items[0].metadata.name}'

• kubectl get pods --field-selector status.phase=Running

selector:

app=elasticsearch-master
chart=elasticsearch
release=elasticsearch-prod

spec:
  podSelector:
    matchLabels:
      app: elasticsearch-master

 apiVersion: policy/v1
kind: PodDisruptionBudget
metadata:
 name: zk-pdb
spec:
 minAvailable: 2
 selector:
   matchLabels:
     app: zookeeper

kind: AWSNodeTemplate
spec:
  subnetSelector:
    karpenter.sh/discovery: ${CLUSTER_NAME}
  securityGroupSelector:
    karpenter.sh/discovery: ${CLUSTER_NAME}

Related

• kubectl set selector
• Kubernetes services
• Kubernetes field selectors
• CKA v1.21: Understand how to use Labels, Selector and Annotations
• 0/2 nodes are available: 1 Too many pods, 1 nodes(s) didn't match Pod's node affinity/selector
• spec.selector

See also

• Kubernetes selectors, PodSelector:, labelSelector:, spec.selector, matchLabels
• Kubernetes labels, selectors, recommended labels, kubectl label, kubectl annotate, Common, kubernetes.io, app.kubernetes.io, MatchLabels:, labels:, Well-Known Labels, Annotations and Taints

https://kubernetes.io/docs/concepts/overview/working-with-objects/field-selectors/