kubectl is the Kubernetes command-line tool which allows us to run commands against Kubernetes clusters. kubectl is installable and available on a variety of Linux , macOS and Windows platforms.
kubectl command line can be used to deploy applications, inspect and manage cluster resources, and view logs. complete list of kubectl operations, see official – kubectl reference documentation.
Kubernetes, also known as K8s, is an open-source container orchestration engine for automating deployment, scaling, and management of containerized applications. The open source project is hosted by the Cloud Native Computing Foundation (CNCF).
Here are some of the most commonly used kubectl commands :
kubectl apply
This command is used to apply the configuration changes to the resources in the Kubernetes cluster and clean up and validate changes.
Examples :
kubectl apply
apply the configuration changes to the resources in the Kubernetes cluster.
kubectl apply –validate
validate the configuration file before applying it.
kubectl apply -f <filename>
apply the configuration changes from the specified YAML file.
kubectl apply -k <directory>
apply the configuration changes from the specified directory.
kubectl apply –prune
remove resources that are no longer specified in the default configuration file
kubectl apply -f <filename> –prune
apply the configuration changes from the specified YAML file and remove any resources that are no longer specified in the file.
kubectl apply -f <filename> –validate
validate the configuration changes from the specified YAML file before applying them.
kubectl apply -f <filename> –dry-run
perform a dry run of the configuration changes before applying them.
kubectl apply -f <filename> –dry-run=client
perform a client-side dry run of the configuration changes from the specified YAML file.
kubectl create
Command is used to create a new resource in the Kubernetes cluster.
Examples:
kubectl create deployment <deployment-name> –image=<image-name>
create a new deployment with the specified name and image.
kubectl create secret
create a new secret in the Kubernetes cluster.
kubectl create secret generic <secret-name> –from-literal=<key>=<value>
create a new generic secret with the specified name and key-value pair.
kubectl delete
Command is used to delete a specific resource.
Examples:
kubectl delete deployment <deployment-name>
delete the specified deployment.
kubectl delete pod <pod-name>
delete the specified pod.
kubectl describe
Command is used to provide detailed information about a specific resource.
Examples:
kubectl describe pod <pod-name>
show the detailed information about the specified pod.
kubectl describe service <service-name>
show the detailed information about the specified service.
kubectl edit
Command is used to edit the configuration of a resource.
Examples:
kubectl edit deployment <deployment-name>
open the configuration file of the specified deployment in the default editor for your system.
kubectl exec
Command is used to execute a command inside a specific container in a pod.
Examples:
kubectl exec -it
Command is used to execute a command inside a specific container in a pod interactively. Examples:
kubectl exec -it <pod-name> <container-name> — /bin/bash
open a terminal inside the specified container in the specified pod and allow you to interact with it.
kubectl get
Command is used to retrieve information about the resources running in the Kubernetes cluster.
Examples:
kubectl get events
show all the events in the default namespace.
Examples:
kubectl get events –all-namespaces
show all the events in all namespaces.
kubectl get pods
show all the pods running in the default namespace.
kubectl get services
show all the services running in the default namespace.
kubectl label
Command is used to add or remove labels from resources.
Examples:
kubectl label pods <pod-name> <label-key>
remove the specified label from the specified pod.
kubectl label pods <pod-name> <label-key>=<label-value>
add the specified label to the specified pod.
kubectl logs
Command is used to retrieve the logs of a specific container in a pod.
Examples:
kubectl logs –follow
Command is used to stream the logs of a specific container in a pod in real-time. Examples:
kubectl logs -f <pod-name> <container-name>
stream the logs of the specified container in the specified pod in real-time.
kubectl logs <pod-name> <container-name>
show the logs of the specified container in the specified pod.
kubectl port-forward:
Command is used to forward the traffic from a specific port of a pod to a local port on your machine.
Examples:
kubectl port-forward <pod-name> <local-port>:<pod-port>
forward the traffic from the specified port of the specified pod to the specified local port on your machine.
kubectl rollout
Command is used to manage rollouts of updates to a deployment.
Examples:
kubectl rollout history
Command is used to view the history of rollouts for a deployment.
kubectl rollout history deployment/<deployment-name> –revision=<revision-number>
show the details of the specified revision of the specified deployment.
kubectl rollout history deployment/<deployment-name>
show the history of rollouts for the specified deployment.
kubectl rollout status deployment/<deployment-name>
show the status of the rollout for the specified deployment.
kubectl rollout undo deployment/<deployment-name>
undo the last rollout for the specified deployment.
kubectl scale
Command is used to scale the number of replicas of a deployment.
Examples:
kubectl scale deployment <deployment-name> –replicas=<number-of-replicas>
scale the specified deployment to the specified number of replicas.
kubectl top:
Command is used to view resource utilization metrics.
Examples:
kubectl top node
show the CPU and memory usage of all the nodes in the cluster.
kubectl top pod <pod-name>
show the CPU and memory usage of the specified pod.