Imperative Commands

Create the pods with below configuration

#### without label
apiVersion: v1
kind: Pod
metadata:
  name: no-label-demo
spec:
  containers:
    - name: nginx
      image: nginx:latest
      ports:
        - containerPort: 80

#### with one label
apiVersion: v1
kind: Pod
metadata:
  name: single-label-demo
  labels:
    app: nginx
spec:
  containers:
    - name: nginx
      image: nginx:latest
      ports:
        - containerPort: 80

#### with multiple labels
apiVersion: v1
kind: Pod
metadata:
  name: multi-labels-demo
  labels:
    app: nginx
    env: dev
spec:
  containers:
    - name: nginx
      image: nginx:latest
      ports:
        - containerPort: 80

Display the pod label

kubectl get pods --show-labels

Filtering the pods based on the label

kubectl get pods -l <key=value>

Adding the labels to the pods

kubectl label pods <podname> <key=value>

Overwrite existing labels in the pods

kubectl label pods <podname> <key=value> --overwrite

Remove the labels from the pods

kubectl label pods <podname> key-

Destroy the pods based on label

kubectl delete pods -l <key=value>

Note: When deleting the pod based on the label, it will delete all the pods if the label exists in the pod configuration.

For example, Assume the pod contains 3 labels.Out of 3 labels, only 1 label matches while executing delete command, then this pod will be deleted.

Label selector - Highlevel

Create Deployment

kubectl create deployment <deployment name> --image=<image name>

kubectl create deployment <deployment name> --image=<image name> --replicas=<number of pods>

Below two commands will not create deployment. Instead, it will evaluate if this command can create deployment. If it creates, what would be the yaml file content kubectl create deployment <deployment name> --image=<image name> --replicas=<number of pods> --dry-run=client

kubectl create deployment <deployment name> --image=<image name> --replicas=<number of pods> --dry-run=client -o yaml