What is Kubectl?

Before we jump into what commands we use, first we need to know what Kubectl is exactly.

Kubectl is a command-line tool used to interact with Kubernetes clusters. It provides a wide range of commands to manage various aspects of the cluster, such as deploying applications, scaling resources, inspecting cluster state, and more.

In layman's terms, Kubectl is a command-line tool used to manage Kubernetes clusters.

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Commands

Since we now know what Kubectl is, let's see what commands are used in managing Kubernetes clusters.

1. kubectl get

Used to retrieve information about various Kubernetes resources.

Examples:

• kubectl get pods: Lists all the pods in the cluster.

• kubectl get deployments: Lists all the deployments in the cluster.

2. kubectl describe

Describes a specific resource in detail.

Examples:

• kubectl describe pod <pod_name>: Displays detailed information about a specific pod.

• kubectl describe service <service_name>: Shows Detailed information about a specific service in the cluster.

3. kubectl create

Creates a resource from a YAML or JSON file.

Example:

• kubectl create -f deployment.yaml: Creates a deployment using the configuration specified in the deployment.yaml file.

4. kubectl apply

Applies changes to a resource or creates a new resource from a YAML or JSON file.

Example:

• kubectl apply -f service.yaml: Applies changes or creates a deployment based on the configuration in the service.yaml file.

5. kubectl delete

Deletes a Resource [Crazy I know🤯]

Examples:

• kubectl delete pod <pod_name>: Deletes a specific pod.

• kubectl delete deployment <deployment_name>: Deletes a deployment.

6. kubectl scale

Changes the number of replicas for a deployment, replicaset, or statefulset.

Example:

• kubectl scale deployment <deployment_name> --replicas=3: Scales a deployment to have three replicas.

• kubectl scale deployment <deployment_name> --replicas=5: Scales a deployment to have 5 replicas.

7. kubectl logs

Prints all the logs of a specific container within a pod.

Example:

• kubectl logs <pod_name>: Displays the logs of the first container in a pod.

• kubectl logs nginx: Return snapshot logs from pod nginx with only one container.

8. kubectl exec

Executes a command within a pod.

Example:

• kubectl exec <pod_name> -- <command>: Executes the specified command within a container of the given pod.

• kubectl exec 123456-7890 -c ruby-container date: Get output from running 'date' in ruby-container from pod 123456-7890.

9. kubectl port-forward

Forward one or more local ports to a pod.

Example:

• kubectl port-forward <pod_name> <local_port>:<pod_port>: Forwards a local port to the specified pod and port.

• kubectl port-forward mypod 8888:5000: Listen on port 8888 locally, forwarding to 5000 in the pod.

10. kubectl run

Used to run a particular image on the cluster.

Example:

• kubectl run nginx --image=nginx: Start a single instance of nginx.

• kubectl run hazelcast --image=hazelcast --port=5701: Start a single instance of hazelcast and let the container expose port 5701.

Happy Learning:)

Mohammed muqafamuddin