Managing Kubernetes clusters efficiently requires fluency with kubectl, the command-line interface for interacting with the Kubernetes API. Whether you’re deploying applications, viewing logs, or debugging infrastructure, this tool is your gateway to smooth cluster operations.

This in-depth cheat sheet will give you a comprehensive reference of how to use kubectl effectively in real-world operations, including advanced flags, filtering tricks, rolling updates, patching, output formatting, and resource exploration.

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Shell Autocompletion

Boost productivity with shell autocompletion for kubectl:

Bash

source <(kubectl completion bash)
echo "source <(kubectl completion bash)" >> ~/.bashrc

ZSH

source <(kubectl completion zsh)
echo '[[ $commands[kubectl] ]] && source <(kubectl completion zsh)' >> ~/.zshrc

Aliases

alias k=kubectl
complete -o default -F __start_kubectl k

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Working with Contexts & Clusters

kubectl config view                        # Show merged config
kubectl config get-contexts               # List contexts
kubectl config current-context            # Show current context
kubectl config use-context my-context     # Switch to context

Set default namespace for future commands:

kubectl config set-context --current --namespace=my-namespace

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Deployments & YAML Management

kubectl apply -f ./manifest.yaml          # Apply resource(s)
kubectl apply -f ./dir/                   # Apply all YAMLs in directory
kubectl create deployment nginx --image=nginx
kubectl explain pod                       # Show pod schema

Apply resources from multiple sources:

kubectl apply -f ./one.yaml -f ./two.yaml
kubectl apply -f https://example.com/config.yaml

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Viewing & Finding Resources

kubectl get pods                          # List all pods
kubectl get pods -o wide                  # Detailed pod listing
kubectl get services                      # List services
kubectl describe pod my-pod               # Detailed pod info

Filter & sort:

kubectl get pods --field-selector=status.phase=Running
kubectl get pods --sort-by='.status.containerStatuses[0].restartCount'

Find pod labels:

kubectl get pods --show-labels

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Updating & Rolling Deployments

kubectl set image deployment/web nginx=nginx:1.19       # Set new image
kubectl rollout status deployment/web                   # Watch rollout
kubectl rollout history deployment/web                  # Show revisions
kubectl rollout undo deployment/web                     # Undo last change
kubectl rollout undo deployment/web --to-revision=2     # Revert to specific

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Editing, Scaling, Deleting

kubectl edit deployment/web                    # Live edit YAML
kubectl scale deployment/web --replicas=5      # Scale up/down
kubectl delete pod my-pod                      # Delete by name
kubectl delete -f pod.yaml                     # Delete from file

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Logs, Execs & Debugging

kubectl logs my-pod                            # View logs
kubectl logs my-pod -c container-name          # Logs from container
kubectl logs my-pod --previous                 # Logs from crashed
kubectl exec my-pod -- ls /                    # Run command
kubectl exec -it my-pod -- bash                # Shell access

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Working with Services

kubectl expose pod nginx --port=80 --target-port=8080   # Create service
kubectl port-forward svc/my-service 8080:80             # Forward to local

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Resource Metrics

kubectl top pod                              # Pod metrics
kubectl top pod --sort-by=cpu                # Sort by CPU
kubectl top node                             # Node metrics

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Patching Resources

Strategic merge patch:

kubectl patch deployment my-deploy -p '{"spec":{"replicas":4}}'

JSON patch with array targeting:

kubectl patch pod my-pod --type='json' -p='[
  {"op": "replace", "path": "/spec/containers/0/image", "value":"nginx:1.21"}
]'

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Cluster & Node Management

kubectl cordon my-node                        # Prevent new pods
kubectl drain my-node                         # Evict pods for maintenance
kubectl uncordon my-node                      # Resume scheduling
kubectl get nodes                             # List all nodes
kubectl describe node my-node                 # Node details

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Output Formatting

kubectl get pods -o json
kubectl get pods -o yaml
kubectl get pods -o custom-columns="NAME:.metadata.name,IMAGE:.spec.containers[*].image"

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Exploring API Resources

kubectl api-resources                         # List all resources
kubectl api-resources --namespaced=false      # Non-namespaced
kubectl api-resources -o wide                 # Extended info

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Logging & Verbosity

kubectl get pods -v=6                         # Debug output
kubectl get deployment -v=9                   # Full API trace

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Deployment Template Example

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  namespace: my-namespace
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:latest
        ports:
        - containerPort: 80

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