This code sets up an alias ‘k’ for the ‘kubectl’ command.

• alias k=kubectl

This code sets up autocompletion for the ‘k’ alias using the __start_kubectl function.

• complete -o default -F __start_kubectl k

Set Current Context Namespace

• k config set-context --current --namespace=my-ns

Creates a deployment with nginxdemos/hello image and 3 replicas.

• k create deploy mydeployment --image=nginxdemos/hello --replicas=3

Exposes the deployment as a NodePort service on port 80.

• k expose deploy mydeployment --type=NodePort --port=80 --target-port=80 --dry-run=client -o yaml

Creates a NodePort service with port mapping and node port specified.

• k create svc nodeport mydeployment --tcp=80:80 --node-port=30009 --dry-run=client -o yaml

This command replaces a Kubernetes pod using the specified JSON file.

It forces the replacement, even if the pod is not ready for termination.

• k replace --force -f ./pod.json

Creates a ConfigMap with username and password literals.

• k create cm webConfigmap --from-literal=username='myuser' --from-literal=password='pswd' -o yaml --dry-run=client

Creates a generic secret with username and password literals.

• k create secret generic websecret --from-literal=username='myuser' --from-literal=password='pswd' -o yaml --dry-run=client

Retrieves and decodes the password from the secret.

• k get secrets websecret -o json |jq -r .data.password |base64 --decode && echo

Updates the image of the deployment to nginxdemos/hello.

• k set image deploy/mydeployment hello=nginxdemos/hello

Shows the rollout history of the deployment.

• k rollout history deployment mydeployment

Retrieves the list of nodes with custom columns.

• k get nodes -o custom-columns=NODE_NAME:.metadata.name,TAINTS:.spec.taints

Applies a taint to the node with specified key-value pair and effect.

• k taint nodes docker-desktop my-key=my-value:NoSchedule

Removes the specified taint from the node.

• k taint nodes docker-desktop my-key=my-value:NoSchedule-

Drains the node by evicting all pods except daemonsets.

• k drain --ignore-daemonsets docker-desktop

Cordon node so that no pod will be scheduled there

• kubectl cordon my-node

get short form for command or api versions

• kubectl api-resources

If we create a replicaset with same label as a pod the pod will become part of replicaset and pod will be counted in replicas number.

If you know the value of an element in json and want to get the path to it

• jq -r 'paths (.. | select (. == "v1")) | join (":")' data.json
• It will be useful in getting path for jsonpath output for example
• k get node -o json |jq -r 'paths (.. | select (. == "docker-desktop")) | join (":")'

If you face an issue with worker node or see that worker node is down use below commands to investigate

• systemctl status kubelet.service
• journalctl -u kubelet
• systemctl deamon-reload
• systemctl restart kubelet

Few more Tips

• Switch Contexts Quickly k config use-context <context-name> Quickly switch between different Kubernetes contexts.
• View All Resources in a Namespace k get all -n <namespace> Get a summary of all resources in a specific namespace.
• Port Forwarding to Access Services Locally k port-forward svc/<service-name> <local-port>:<service-port> Access a service locally by forwarding a port.
• Scale a Deployment k scale deploy <deployment-name> --replicas=<number-of-replicas> Easily scale the number of replicas in a deployment.
• Debugging Pods k describe pod <pod-name> k logs <pod-name> k exec -it <pod-name> -- /bin/bash Use these commands to describe, view logs, and execute commands inside a pod for debugging.
• Rolling Back a Deployment k rollout undo deploy/<deployment-name> Roll back to a previous deployment revision.
• View Resource Usage k top nodes k top pods Monitor resource usage of nodes and pods.
• Apply Changes from a File k apply -f <file.yaml> Apply changes to your cluster from a YAML file.
• Delete Resources by Label k delete pods,svc -l <label-key>=<label-value> Delete multiple resources by specifying a label.
• View Events k get events --sort-by='.metadata.creationTimestamp' View and sort events to troubleshoot issues.