Commands

kubectl get all

kubectl get all -o wide

kubectl get all --all-namespaces -o wide # --al-namespaces -> -A

kubectl get nodes

kubectl get pods

kubectl cluster-info

kubectl get events

kubectl get services

kubectl create -f input.yaml

kubectl delete pod $POD_NAME

kubectl exec -it busybox /bin/sh

kubectl exec busybox nslookup kubernetes.default

kubectl describe nodes

kubeadm reset ^{# Reverts any changes made by kubeadm init or kubeadm join}

kubeadm token list ^{# Run this on master node to get token}

kubeadm join --token $token $master_node_ip:6443 --discovery-token-unsafe-skip-ca-verification ^{# Don't skip verf, its just for local}

kubectl get netpol -n $NAMESPACE ^{# List network polices. (netpol or networkpolicy)}

kubectl describe netpol $NET_POLICY_NAME -n $NAMESPACE

kubectl delete netpol $NET_POLICY_NAME -n $NAMESPACE

kubectl delete -f $NET_POLICY_RESOURCE.yaml -n $NAMESPACE

kubectl edit netpol $NET_POLICY_NAME

kubectl edit netpol $NET_POLICY_NAME -n default -o json

kubectl edit -f $NET_POLICY_RESOURCE.yaml

KUBE_EDITOR='nano' kubectl edit netpol access-nginx -n default _{# nano or vim etc}

kubectl config set-context --current --namespace=$NAMESPACE _{# set default NAMESPACE}

kubectl get netpol $NET_POLICY_NAME -n $NAMESPACE -o json

kubectl config view --minify --output 'jsonpath={..namespace}' _{# get current namespace}

kubectl get pods -n $NAMESPACE -w _{# -w is watch}

kubectl get serviceaccounts -A -o yaml _{# list all service accounts}

kubectl delete pod <pod_name> --grace-period=0 --force -n _{# force delete pod}

--dry-run It just displays the yaml of the manifest but doesn't creates the object.

$ kubectl create namespace ttt -o yaml --dry-run
apiVersion: v1
kind: Namespace
metadata:
  creationTimestamp: null
  name: ttt
spec: {}
status: {}

Kind of MAN page of the object `explain

$ kubectl  | grep explain
  explain        Documentation of resources


$ kubectl explain pod
KIND:     Pod
VERSION:  v1

DESCRIPTION:
     Pod is a collection of containers that can run on a host. This resource is
     created by clients and scheduled onto hosts.

FIELDS:
   apiVersion	<string>
     APIVersion defines the versioned schema of this representation of an
     object. Servers should convert recognized schemas to the latest internal
     value, and may reject unrecognized values. More info:
     https://git.k8s.io/community/contributors/devel/api-conventions.md#resources

   kind	<string>
...

$ kubectl explain pod.apiVersion

$ kubectl explain pod.spec

Show complete schema of the object

$ kubectl explain pod --recursive
KIND:     Pod
VERSION:  v1

DESCRIPTION:
     Pod is a collection of containers that can run on a host. This resource is
     created by clients and scheduled onto hosts.

FIELDS:
   apiVersion	<string>
   kind	<string>
   metadata	<Object>
      annotations	<map[string]string>
      clusterName	<string>
      creationTimestamp	<string>
      deletionGracePeriodSeconds	<integer>
      deletionTimestamp	<string>
      finalizers	<[]string>
      generateName	<string>
      generation	<integer>
      initializers	<Object>
         pending	<[]Object>
            name	<string>
         result	<Object>
            apiVersion	<string>
            code	<integer>
            details	<Object>
               causes	<[]Object>
                  field	<string>
                  message	<string>
                  reason	<string>
...


$ kubectl explain pod.metadata --recursive
KIND:     Pod
VERSION:  v1

RESOURCE: metadata <Object>

DESCRIPTION:
     Standard object's metadata. More info:
     https://git.k8s.io/community/contributors/devel/api-conventions.md#metadata

     ObjectMeta is metadata that all persisted resources must have, which
     includes all objects users must create.

FIELDS:
   annotations	<map[string]string>
   clusterName	<string>
   creationTimestamp	<string>
   deletionGracePeriodSeconds	<integer>
   deletionTimestamp	<string>
   finalizers	<[]string>
   generateName	<string>
   generation	<integer>

Supported API resources on the server

$ kubectl api-resources
NAME                              SHORTNAMES   APIGROUP                       NAMESPACED   KIND
bindings                                                                      true         Binding
componentstatuses                 cs                                          false        ComponentStatus
configmaps                        cm                                          true         ConfigMap
...

Supported API versions on the server, in the form of "group/version"

$ kubectl api-versions
admissionregistration.k8s.io/v1beta1
apiextensions.k8s.io/v1beta1
apiregistration.k8s.io/v1
apiregistration.k8s.io/v1beta1
apps/v1
...
v1