2.02 Labels and Selectors

• For example, here's a manifest for a Pod that has two labels environment: production and app: nginx:

Pod Labels Configuration in YAML (Click to Expand)

apiVersion: v1
kind: Pod
metadata:
  name: label-demo
  labels:
    environment: production  # Label 1
    app: nginx               # Label 2
spec:
  containers:
    - name: nginx
      image: nginx:1.14.2
      ports:
        - containerPort: 80

kubectl get pods --selector app=nginx (or)
kubectl get pods -l env=prod,bu=finance,tier=frontend #if Pods have multiple labels

🔎 Explanation:
-l (or --selector) lets you filter by labels.
Comma-separated labels mean AND condition → Pod must match all of them.

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Annotation

• Labels and selectors are primarily used to group and identify Kubernetes objects, whereas annotations serve to store additional information for reference.

• For instance, annotations can capture details such as tool name, version, build information, and other metadata.

Pod with Annotation in YAML (Click to Expand)

apiVersion: v1
kind: Pod
metadata:
  name: annotations-demo
  annotations:
    imageregistry: "https://hub.docker.com/"  # Annotation
spec:
  containers:
    - name: nginx
      image: nginx:1.14.2
      ports:
        - containerPort: 80