# Main kubectl commands CLI Tool to interact with our K8s cluster In order for kubectl to access a K8s cluster, it needs a kubeconfig file, which is created automatically when deploying our minikube cluster By default, config file is located at \~/.kube/config ![](/files/puaNAMzAjNHBUtSdDLgf) **kubectl api-versions** − It prints the supported versions of API on the cluster. ``` $ kubectl api-version; ``` **kubectl apply** − It has the capability to configure a resource by file or stdin. ``` $ kubectl apply –f ``` **kubectl attach** − This attaches things to the running container. ``` $ kubectl attach –c $ kubectl attach 123456-7890 -c tomcat-conatiner ``` **kubectl autoscale** − This is used to auto scale pods which are defined such as Deployment, replica set, Replication Controller. ``` $ kubectl autoscale (-f FILENAME | TYPE NAME | TYPE/NAME) [--min = MINPODS] -- max = MAXPODS [--cpu-percent = CPU] [flags] $ kubectl autoscale deployment foo --min = 2 --max = 10 ``` **kubectl cluster-info** − It displays the cluster Info. ``` $ kubectl cluster-info ``` **kubectl cluster-info dump** − It dumps relevant information regarding cluster for debugging and diagnosis. ``` $ kubectl cluster-info dump $ kubectl cluster-info dump --output-directory = /path/to/cluster-state ``` **kubectl config** − Modifies the kubeconfig file. ``` $ kubectl config $ kubectl config –-kubeconfig ``` **kubectl config current-context** − It displays the current context. ``` $ kubectl config current-context #deploys the current context ``` **kubectl config delete-cluster** − Deletes the specified cluster from kubeconfig. ``` $ kubectl config delete-cluster ``` **kubectl config delete-context** − Deletes a specified context from kubeconfig. ``` $ kubectl config delete-context ``` **kubectl config get-clusters** − Displays cluster defined in the kubeconfig. ``` $ kubectl config get-cluster $ kubectl config get-cluster ``` **kubectl config get-contexts** − Describes one or many contexts. ``` $ kubectl config get-context ``` **kubectl config set-cluster** − Sets the cluster entry in Kubernetes. ``` $ kubectl config set-cluster NAME [--server = server] [--certificateauthority = path/to/certificate/authority] [--insecure-skip-tls-verify = true] ``` **kubectl config set-context** − Sets a context entry in kubernetes entrypoint. ``` $ kubectl config set-context NAME [--cluster = cluster_nickname] [-- user = user_nickname] [--namespace = namespace] $ kubectl config set-context prod –user = vipin-mishra ``` **kubectl config set-credentials** − Sets a user entry in kubeconfig. ``` $ kubectl config set-credentials cluster-admin --username = vipin -- password = uXFGweU9l35qcif ``` **kubectl config set** − Sets an individual value in kubeconfig file. ``` $ kubectl config set PROPERTY_NAME PROPERTY_VALUE ``` **kubectl config unset** − It unsets a specific component in kubectl. ``` $ kubectl config unset PROPERTY_NAME PROPERTY_VALUE ``` **kubectl config use-context** − Sets the current context in kubectl file. ``` $ kubectl config use-context ``` **kubectl config view** ``` $ kubectl config view $ kubectl config view –o jsonpath='{.users[?(@.name == "e2e")].user.password}' ``` **kubectl cp** − Copy files and directories to and from containers. ``` $ kubectl cp $ kubectl cp /tmp/foo :/tmp/bar -c ``` **kubectl create** − To create resource by filename of or stdin. To do this, JSON or YAML formats are accepted. ``` $ kubectl create –f $ cat | kubectl create –f - ``` In the same way, we can create multiple things as listed using the **create** command along with **kubectl**. * deployment * namespace * quota * secret docker-registry * secret * secret generic * secret tls * serviceaccount * service clusterip * service loadbalancer * service nodeport **kubectl delete** − Deletes resources by file name, stdin, resource and names. ``` $ kubectl delete –f ([-f FILENAME] | TYPE [(NAME | -l label | --all)]) ``` **kubectl describe** − Describes any particular resource in kubernetes. Shows details of resource or a group of resources. ``` $ kubectl describe $ kubectl describe pod tomcat ``` **kubectl drain** − This is used to drain a node for maintenance purpose. It prepares the node for maintenance. This will mark the node as unavailable so that it should not be assigned with a new container which will be created. ``` $ kubectl drain tomcat –force ``` **kubectl edit** − It is used to end the resources on the server. This allows to directly edit a resource which one can receive via the command line tool. ``` $ kubectl edit -- COMMAND < args...> $ kubectl exec tomcat 123-5-456 date ``` **kubectl expose** − This is used to expose the Kubernetes objects such as pod, replication controller, and service as a new Kubernetes service. This has the capability to expose it via a running container or from a **yaml** file. ``` $ kubectl expose (-f FILENAME | TYPE NAME) [--port=port] [--protocol = TCP|UDP] [--target-port = number-or-name] [--name = name] [--external-ip = external-ip-ofservice] [--type = type] $ kubectl expose rc tomcat –-port=80 –target-port = 30000 $ kubectl expose –f tomcat.yaml –port = 80 –target-port = ``` **kubectl get** − This command is capable of fetching data on the cluster about the Kubernetes resources. ``` $ kubectl get [(-o|--output=)json|yaml|wide|custom-columns=...|custom-columnsfile=...| go-template=...|go-template-file=...|jsonpath=...|jsonpath-file=...] (TYPE [NAME | -l label] | TYPE/NAME ...) [flags] ``` For example, ``` $ kubectl get pod $ kubectl get service ``` **kubectl logs** − They are used to get the logs of the container in a pod. Printing the logs can be defining the container name in the pod. If the POD has only one container there is no need to define its name. ``` $ kubectl logs [-f] [-p] POD [-c CONTAINER] Example $ kubectl logs tomcat. $ kubectl logs –p –c tomcat.8 ``` **kubectl port-forward** − They are used to forward one or more local port to pods. ``` $ kubectl port-forward POD [LOCAL_PORT:]REMOTE_PORT [...[LOCAL_PORT_N:]REMOTE_PORT_N] $ kubectl port-forward tomcat 3000 4000 $ kubectl port-forward tomcat 3000:5000 ``` **kubectl replace** − Capable of replacing a resource by file name or **stdin**. ``` $ kubectl replace -f FILENAME $ kubectl replace –f tomcat.yml $ cat tomcat.yml | kubectl replace –f - ``` **kubectl rolling-update** − Performs a rolling update on a replication controller. Replaces the specified replication controller with a new replication controller by updating a POD at a time. ``` $ kubectl rolling-update OLD_CONTROLLER_NAME ([NEW_CONTROLLER_NAME] -- image = NEW_CONTAINER_IMAGE | -f NEW_CONTROLLER_SPEC) $ kubectl rolling-update frontend-v1 –f freontend-v2.yaml ``` **kubectl rollout** − It is capable of managing the rollout of deployment. ``` $ Kubectl rollout $ kubectl rollout undo deployment/tomcat ``` Apart from the above, we can perform multiple tasks using the rollout such as − * rollout history * rollout pause * rollout resume * rollout status * rollout undo **kubectl run** − Run command has the capability to run an image on the Kubernetes cluster. ``` $ kubectl run NAME --image = image [--env = "key = value"] [--port = port] [-- replicas = replicas] [--dry-run = bool] [--overrides = inline-json] [--command] -- [COMMAND] [args...] $ kubectl run tomcat --image = tomcat:7.0 $ kubectl run tomcat –-image = tomcat:7.0 –port = 5000 ``` **kubectl scale** − It will scale the size of Kubernetes Deployments, ReplicaSet, Replication Controller, or job. ``` $ kubectl scale [--resource-version = version] [--current-replicas = count] -- replicas = COUNT (-f FILENAME | TYPE NAME ) $ kubectl scale –-replica = 3 rs/tomcat $ kubectl scale –replica = 3 tomcat.yaml ``` **kubectl set image** − It updates the image of a pod template. ``` $ kubectl set image (-f FILENAME | TYPE NAME) CONTAINER_NAME_1 = CONTAINER_IMAGE_1 ... CONTAINER_NAME_N = CONTAINER_IMAGE_N $ kubectl set image deployment/tomcat busybox = busybox ngnix = ngnix:1.9.1 $ kubectl set image deployments, rc tomcat = tomcat6.0 --all ``` **kubectl set resources** − It is used to set the content of the resource. It updates resource/limits on object with pod template. ``` $ kubectl set resources (-f FILENAME | TYPE NAME) ([--limits = LIMITS & -- requests = REQUESTS] $ kubectl set resources deployment tomcat -c = tomcat -- limits = cpu = 200m,memory = 512Mi ``` **kubectl top node** − It displays CPU/Memory/Storage usage. The top command allows you to see the resource consumption for nodes. ``` $ kubectl top node [node Name] ``` The same command can be used with a pod as well. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. 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