🛠 Kubernetes Commands and Concepts

🚀 Kubernetes Commands and Concepts#

📜 kubectl Cheat Sheet#

1. Basic Commands#

• Cluster Info:

  • kubectl cluster-info - Display cluster information.
  • kubectl version - Show client and server versions.
  • kubectl get nodes - List all nodes in the cluster.

• Namespace Management:

  • kubectl get namespaces - List all namespaces.
  • kubectl create namespace <namespace> - Create a new namespace.
  • kubectl delete namespace <namespace> - Delete a namespace.
  • kubectl config set-context --current --namespace=<namespace> - Set default namespace.

• Resource Overview:

  • kubectl get all - Show all resources in the default namespace.
  • kubectl get pods - List all pods in the namespace.
  • kubectl get services - List all services in the namespace.

2. Managing Pods#

• Create and Delete Pods:

  • kubectl run <pod-name> --image=<image> - Create a pod.
  • kubectl delete pod <pod-name> - Delete a pod.

• Inspect Pods:

  • kubectl describe pod <pod-name> - Show detailed pod information.
  • kubectl logs <pod-name> - View pod logs.
  • kubectl exec -it <pod-name> -- <command> - Execute a command in the pod.

3. Deployments#

• Create and Manage Deployments:

  • kubectl create deployment <name> --image=<image> - Create a deployment.
  • kubectl scale deployment <name> --replicas=<number> - Scale a deployment.
  • kubectl rollout restart deployment <name> - Restart a deployment.

• Check Deployment Status:

  • kubectl get deployments - List all deployments.
  • kubectl describe deployment <name> - Show deployment details.
  • kubectl rollout status deployment <name> - Check rollout status.

• Update Deployments:

  • kubectl set image deployment/<name> <container>=<new-image> - Update the container image.
  • kubectl rollout undo deployment <name> - Roll back to the previous version.

4. Services and Networking#

• Create and Manage Services:

  • kubectl expose pod <pod-name> --type=<type> --port=<port> - Expose a pod as a service.
  • kubectl get services - List all services.
  • kubectl delete service <service-name> - Delete a service.

• Service Types:

  • ClusterIP: Default; accessible only within the cluster.
  • NodePort: Exposes service on a static port on each node.
  • LoadBalancer: Exposes service externally via a cloud provider.

5. ConfigMaps and Secrets#

• ConfigMaps:

  • kubectl create configmap <name> --from-literal=<key>=<value> - Create a ConfigMap.
  • kubectl get configmaps - List all ConfigMaps.
  • kubectl describe configmap <name> - View ConfigMap details.

• Secrets:

  • kubectl create secret generic <name> --from-literal=<key>=<value> - Create a Secret.
  • kubectl get secrets - List all Secrets.
  • kubectl describe secret <name> - View Secret details.

6. Namespaces#

• kubectl get namespaces - List all namespaces.
• kubectl create namespace <name> - Create a namespace.
• kubectl delete namespace <name> - Delete a namespace.

7. Debugging#

• kubectl logs <pod-name> - View pod logs.
• kubectl describe pod <pod-name> - Detailed pod description.
• kubectl exec -it <pod-name> -- /bin/sh - Access a shell inside the pod.

📝 YAML Templates for Common Kubernetes Objects#

Pod#

apiVersion: v1
kind: Pod
metadata:
  name: my-pod
  namespace: default
spec:
  containers:
  - name: my-container
    image: nginx:latest
    ports:
    - containerPort: 80