kubectl

kubectl is the primary command-line tool for interacting with Kubernetes clusters. It allows you to deploy applications, inspect and manage cluster resources, and view logs. Mastery of kubectl is essential for DevOps engineers working with AWS EKS, Azure AKS, GCP GKE, NixOS, and WSL environments.

Installation

macOS (Homebrew):

brew install kubectl

Linux (Debian/Ubuntu):

sudo apt-get update && sudo apt-get install -y kubectl

NixOS (declarative): Add to your /etc/nixos/configuration.nix:

environment.systemPackages = with pkgs; [ kubectl ];

Then run:

sudo nixos-rebuild switch

Windows (WSL): Install via Chocolatey or manually download the binary from the official docs.

Quick Reference: Common kubectl Commands

Cluster Management

  • kubectl cluster-info – Show cluster endpoints

  • kubectl version – Show client/server versions

  • kubectl config view – Show kubeconfig

  • kubectl get all --all-namespaces – List all resources in all namespaces

Resource Listing

  • kubectl get namespaces – List all namespaces

  • kubectl get pods – List all pods in current namespace

  • kubectl get pods -o wide – Detailed pod info

  • kubectl get pods --field-selector=spec.nodeName=<node> – Pods on a node

  • kubectl get rc,services – List replication controllers and services

Deployments & Rollouts

  • kubectl get deployment – List deployments

  • kubectl describe deployment <name> – Deployment details

  • kubectl edit deployment <name> – Edit deployment

  • kubectl create deployment <name> --image=<image> – Create deployment

  • kubectl delete deployment <name> – Delete deployment

  • kubectl rollout status deployment <name> – Rollout status

  • kubectl rollout history deployment/<name> – Rollout history

  • kubectl rollout undo deployment/<name> – Rollback deployment

  • kubectl rollout restart deployment/<name> – Restart deployment

Pods

  • kubectl get pod – List pods

  • kubectl describe pod <name> – Pod details

  • kubectl logs <pod> – Pod logs

  • kubectl logs -f <pod> – Follow logs

  • kubectl exec -it <pod> -- /bin/sh – Shell into pod

  • kubectl delete pod <name> – Delete pod

Namespaces

  • kubectl create namespace <name> – Create namespace

  • kubectl get namespace – List namespaces

  • kubectl describe namespace <name> – Namespace details

  • kubectl delete namespace <name> – Delete namespace

Nodes

  • kubectl get nodes – List nodes

  • kubectl describe node <name> – Node details

  • kubectl cordon <node> – Mark node unschedulable

  • kubectl drain <node> – Prepare node for maintenance

  • kubectl uncordon <node> – Mark node schedulable

  • kubectl top node – Node resource usage

DaemonSets

  • kubectl get daemonset – List daemonsets

  • kubectl describe ds <name> -n <namespace> – DaemonSet details

  • kubectl edit daemonset <name> – Edit DaemonSet

  • kubectl delete daemonset <name> – Delete DaemonSet

Events

  • kubectl get events – List events

  • kubectl get events --field-selector type=Warning – List warnings

Logs

  • kubectl logs <pod> – Pod logs

  • kubectl logs -c <container> <pod> – Container logs

  • kubectl logs --since=1h <pod> – Last hour logs

  • kubectl logs --tail=20 <pod> – Last 20 lines

  • kubectl logs --previous <pod> – Previous pod logs

Services & Service Accounts

  • kubectl get services – List services

  • kubectl describe service <name> – Service details

  • kubectl expose deployment <name> – Expose as service

  • kubectl get serviceaccounts – List service accounts

  • kubectl describe serviceaccount <name> – Service account details

Secrets

  • kubectl create secret generic <name> --from-literal=key=value – Create secret

  • kubectl get secrets – List secrets

  • kubectl describe secret <name> – Secret details

  • kubectl delete secret <name> – Delete secret

Real-World DevOps Example: Rolling Update

kubectl set image deployment/myapp myapp=nginx:1.25.0
kubectl rollout status deployment/myapp
kubectl rollout undo deployment/myapp

Best Practices

  • Use kubectl --context and --namespace to avoid mistakes in multi-cluster/multi-namespace environments

  • Use kubectl explain <resource> to discover resource fields

  • Use kubectl apply -f <file.yaml> for declarative resource management

  • Integrate kubectl with CI/CD (GitHub Actions, Azure Pipelines, GitLab CI)

  • Use kubectx/kubens for fast context/namespace switching

  • Never run destructive commands (delete, drain) without double-checking the context/namespace

References

Tip: Use shell aliases and prompt tools (e.g., kube-ps1) to display current context/namespace and avoid costly mistakes.

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