kubectl

kubectl is the Kubernetes command-line tool that communicates with the Kubernetes API server to manage cluster resources such as pods, deployments, services, and more.

It supports imperative commands to create, update, and delete resources, as well as declarative workflows by applying YAML or JSON configuration files.

Common kubectl Commands

Cluster Information

• Get cluster info

  kubectl cluster-info

• Get cluster nodes

  kubectl get nodes

Working with Pods

• List all pods in default namespace

  kubectl get pods

• Get detailed info about a pod

  kubectl describe pod <pod-name>

• Create a pod from a YAML file

  kubectl apply -f pod.yaml

• Delete a pod

  kubectl delete pod <pod-name>

• View logs from a pod

  kubectl logs <pod-name>

Managing Deployments

• List deployments

  kubectl get deployments

• Create/update deployment from YAML

  kubectl apply -f deployment.yaml

• Scale a deployment

  kubectl scale deployment/<deployment-name> --replicas=3

• Rollout status

  kubectl rollout status deployment/<deployment-name>

Services

• List services

  kubectl get svc

• Create a service from YAML

  kubectl apply -f service.yaml

• Expose deployment as a service

  kubectl expose deployment <deployment-name> --type=LoadBalancer --port=80

Namespaces

• List namespaces

  kubectl get namespaces

• Set namespace for current context

  kubectl config set-context --current --namespace=<namespace>

Configuration and Context

• View current context

  kubectl config current-context

• List contexts

  kubectl config get-contexts

• Switch context

  kubectl config use-context <context-name>

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Advanced Usage

Labeling and Selecting

• Add a label to a resource

  kubectl label pods <pod-name> env=prod

• Select resources by label

  kubectl get pods -l env=prod

Port Forwarding

Forward a local port to a pod’s port:

kubectl port-forward pod/<pod-name> 8080:80

Rolling Updates and Rollbacks

• Rollout update deployment

  kubectl rollout restart deployment/<deployment-name>

• Rollback to previous revision

  kubectl rollout undo deployment/<deployment-name>

Debugging

• Execute a command inside a pod

  kubectl exec -it <pod-name> -- /bin/bash

• Describe a resource to get detailed info and events

  kubectl describe <resource> <name>

• Remove stuck finalizers

  kubectl patch <resource> <name> -n <namespace> -p '{"metadata":{"finalizers":[]}}' --type=merge