Interacting with the cluster using kubectl.

Category : Kubernetes | Sub Category : Learn Kubernetes | By Prasad Bonam Last updated: 2023-11-22 07:30:58 Viewed : 227

Interacting with a Kubernetes cluster using kubectl involves various commands to manage resources, inspect the cluster state, and troubleshoot issues. Here is a guide to some common kubectl commands:

1. Basic Commands:

• Get Resources:

  • List all resources of a specific type:

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    kubectl get pods
    kubectl get services
    

  • Get detailed information about a resource:

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    kubectl get pods <pod-name> -o yaml
    

• Create and Apply:

  • Create or apply a resource from a YAML file:

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    kubectl apply -f my-pod.yaml
    

• Delete Resource:

  • Delete a resource by name or from a YAML file:

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    kubectl delete pod <pod-name>
    kubectl delete -f my-pod.yaml
    

2. Inspecting Cluster:

• Cluster Info:

  • Display the cluster information:

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    kubectl cluster-info
    

• Node Info:

  • Get information about nodes in the cluster:

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    kubectl get nodes
    

• Describe:

  • Describe a resource for detailed information:

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    kubectl describe pod <pod-name>
    kubectl describe node <node-name>
    

3. Working with Pods:

• Logs:

  • View the logs of a pod:

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    kubectl logs <pod-name>
    

• Exec into Pod:

  • Run commands inside a pod:

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

• Port Forwarding:

  • Forward a local port to a port on a pod:

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

4. Managing Deployments:

• Deployments:

  • List and manage deployments:

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    kubectl get deployments
    kubectl scale deployment <deployment-name> --replicas=3
    

• Rolling Update:

  • Perform a rolling update of a deployment:

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    kubectl set image deployment/<deployment-name> nginx=nginx:1.17 --record
    

5. Services:

• Services:

  • List and manage services:

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    kubectl get services
    

• Expose Deployment:

  • Expose a deployment as a service:

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    kubectl expose deployment <deployment-name> --type=NodePort --port=8080
    

6. Namespaces:

• Create and Switch Namespace:

  • Create a new namespace and switch to it:

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

• List Resources in Namespace:

  • List resources in a specific namespace:

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    kubectl get pods --namespace=my-namespace
    

7. Troubleshooting:

• Events:

  • View events related to resources:

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    kubectl get events
    

• Describe Resource for Troubleshooting:

  • Describe a resource to troubleshoot issues:

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    kubectl describe pod <pod-name>
    

• Logs and Exec for Troubleshooting:

  • Check logs and exec into a pod to troubleshoot issues:

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

These are just a few examples of the numerous kubectl commands available. The command-line tool is powerful and flexible, allowing you to manage and interact with your Kubernetes cluster efficiently. You can explore more commands and options in the kubectl documentation.