Kubectl Commands with Examples

kubectl is a command-line tool for interacting with your Kubernetes cluster. It lets you manage Kubernetes resources like pods, deployments, services, and more.

1. `kubectl` Basics

1.1 Help and Version Information

kubectl version
Shows the kubectl client and server versions.
```
  kubectl version --client
```
kubectl help
Provides help information for kubectl.
```
  kubectl help
```

2. Context and Configuration

2.1 Context Management

kubectl config get-contexts
Lists all available contexts.
```
  kubectl config get-contexts
```
kubectl config use-context
Switches to a different context.
```
  kubectl config use-context my-cluster
```
kubectl config current-context
Displays the current context.
```
  kubectl config current-context
```

2.2 Config View and Edit

kubectl config view
Displays merged kubeconfig settings.
```
  kubectl config view
```
kubectl config set-context
Modifies a context entry in the kubeconfig file.
```
  kubectl config set-context my-context --namespace=dev
```

3. Managing Kubernetes Resources

3.1 Pods

kubectl get pods
Lists all pods in the default namespace.
```
  kubectl get pods
```
kubectl get pods -n my-namespace
Lists all pods in a specific namespace.
```
  kubectl get pods -n my-namespace
```
kubectl describe pod my-pod
Provides detailed information about a specific pod.
```
  kubectl describe pod my-pod
```
kubectl logs my-pod
Retrieves logs from a specific pod.
```
  kubectl logs my-pod
```
kubectl exec -it my-pod -- /bin/bash
Executes a command inside a running pod.
```
  kubectl exec -it my-pod -- /bin/bash
```

3.2 Deployments

kubectl get deployments
Lists all deployments in the default namespace.
```
  kubectl get deployments
```
kubectl create deployment nginx-deployment --image=nginx
Creates a new deployment.
```
  kubectl create deployment nginx-deployment --image=nginx
```
kubectl scale deployment nginx-deployment --replicas=4
Scales a deployment to a specified number of replicas.
```
  kubectl scale deployment nginx-deployment --replicas=4
```
kubectl rollout restart deployment/nginx-deployment
Restarts the pods managed by a deployment.
```
  kubectl rollout restart deployment/nginx-deployment
```

3.3 Services

kubectl get services
Lists all services in the default namespace.
```
  kubectl get services
```
kubectl expose deployment nginx-deployment --type=NodePort --port=80
Exposes a deployment as a service.
```
  kubectl expose deployment nginx-deployment --type=NodePort --port=80
```
kubectl delete service nginx-service
Deletes a service by name.
```
  kubectl delete service nginx-service
```

3.4 Nodes

kubectl get nodes
Lists all nodes in the cluster.
```
  kubectl get nodes
```
kubectl describe node my-node
Provides detailed information about a specific node.
```
  kubectl describe node my-node
```

3.5 ConfigMaps

kubectl create configmap my-config --from-literal=key1=value1
Creates a ConfigMap from a literal value.
```
  kubectl create configmap my-config --from-literal=key1=value1
```
kubectl get configmaps
Lists all ConfigMaps.
```
  kubectl get configmaps
```
kubectl describe configmap my-config
Provides detailed information about a specific ConfigMap.
```
  kubectl describe configmap my-config
```

3.6 Secrets

kubectl create secret generic my-secret --from-literal=password=myPassword
Creates a secret from a literal value.
```
  kubectl create secret generic my-secret --from-literal=password=myPassword
```
kubectl get secrets
Lists all secrets.
```
  kubectl get secrets
```
kubectl describe secret my-secret
Provides detailed information about a specific secret.
```
  kubectl describe secret my-secret
```

4. Advanced Resource Management

4.1 Apply Changes

kubectl apply -f my-deployment.yaml
Applies changes from a YAML or JSON file.
```
  kubectl apply -f my-deployment.yaml
```

4.2 Delete Resources

kubectl delete pod my-pod
Deletes a pod by name.
```
  kubectl delete pod my-pod
```
kubectl delete -f my-resource.yaml
Deletes resources defined in a YAML or JSON file.
```
  kubectl delete -f my-resource.yaml
```

4.3 Patching Resources

kubectl patch deployment my-deployment -p '{"spec":{"replicas":5}}'
Updates part of a resource specification.
```
  kubectl patch deployment my-deployment -p '{"spec":{"replicas":5}}'
```

5. Monitoring and Debugging

5.1 Events

kubectl get events
Lists all events in the cluster.
```
  kubectl get events
```

5.2 Resource Usage

kubectl top nodes
Displays CPU and memory usage for nodes.
```
  kubectl top nodes
```
kubectl top pods
Displays CPU and memory usage for pods.
```
  kubectl top pods
```

5.3 Port Forwarding

kubectl port-forward pod/my-pod 8080:80
Forwards a local port to a port on a pod.
```
  kubectl port-forward pod/my-pod 8080:80
```

6. Label and Annotate Resources

6.1 Label Resources

kubectl label pod my-pod environment=production
Adds a label to a pod.
```
  kubectl label pod my-pod environment=production
```

6.2 Annotate Resources

kubectl annotate pod my-pod description='My production pod'
Adds an annotation to a pod.
```
  kubectl annotate pod my-pod description='My production pod'
```

7. Role-Based Access Control (RBAC)

7.1 List Roles and RoleBindings

kubectl get roles
Lists roles in the current namespace.
```
  kubectl get roles
```
kubectl get rolebindings
Lists role bindings in the current namespace.
```
  kubectl get rolebindings
```

8. Networking

8.1 Expose Resources

kubectl expose pod redis --port=6379 --name redis-service --type=ClusterIP
Exposes a pod with a service.
```
  kubectl expose pod redis --port=6379 --name redis-service --type=ClusterIP
```

8.2 Manage Ingress

kubectl get ingress
Lists all ingress resources.
```
  kubectl get ingress
```
kubectl describe ingress my-ingress
Provides detailed information about a specific ingress.
```
  kubectl describe ingress my-ingress
```

9. Debugging with `kubectl`

9.1 Debug a Node

kubectl debug node/my-node --image=busybox
Creates a debugging container on a node.

kubectl debug node/my-node --image=busybox


#### **9.2 Debug a Pod**
- **`kubectl debug pod/my-pod -it --image=busybox --target=my-container`**  
Attaches a debugging container to a running pod.

```sh
kubectl debug pod/my-pod -it --image=busybox --target=my-container

10. Miscellaneous Commands

10.1 Run a Pod Temporarily

kubectl run my-shell --rm -i --tty --image busybox -- /bin/sh
Runs a temporary shell pod for debugging.
```
  kubectl run my-shell --rm -i --tty --image busybox -- /bin/sh
```

10.2 Taint and Tolerate Nodes

kubectl taint nodes my-node key=value:NoSchedule
Adds a taint to a node.
```
  kubectl taint nodes my-node key=value:NoSchedule
```

Conclusion

This Article covers all the essential kubectl commands. This comprehensive guide should provide a solid foundation to learn and practice all the kubectl commands.

Best of Luck!