Kubernetes Commands

Commons

Create, replace and update an object from yml file.

• kubectl create -f <PATH_FILE>
• kubectl replace -f <PATH_FILE>
• kubectl apply -f <PATH_FILE>

Get pods, replicaset, deployments and services objects.

• kubectl get all

Get all objects from a resource.

• kubectl get <RESOURCE_NAME>
  • kubectl get pods

Describe an object from a resource.

• kubectl describe <RESOURCE_NAME> <OBJECT_NAME>
  • kubectl describe pod nginx

Edit an object from a resource.

• kubectl edit <RESOURCE_NAME> <OBJECT_NAME>
  • kubectl edit pod nginx

Delete an object from a resource.

• kubectl delete <RESOURCE_NAME> <OBJECT_NAME>
  • kubectl delete pod nginx
  • kubectl delete pod nginx --grace-period=0 --force

Pods (Pod)

Create a pod with a single container

• kubectl run <POD_NAME> --image <CONTAINER_IMAGE>
  • kubectl run nginx --image nginx
  • Options:
    • add labels
      • kubectl run <POD_NAME> --image <CONTAINER_IMAGE> --labels <MY_KEY>=<MY_VALUE>
      • kubectl run nginx --image nginx --labels my-key=my-value

Get a shell to a running container kubectl exec <POD_NAME> -it -- <MY_COMMAND>

• kubectl exec my-pod -it -- bash

Get logs from a pod kubectl logs <POD_NAME> <CONTAINER_NAME>

• kubectl logs my-pod my-container

Replicaset (rs)

Scale replicaset

• kubectl scale rs <RS_NAME> --replicas <REPLICAS_NUMBER>
  • kubectl scale rs my-rs --replicas 5

Deployment (deploy)

Create a deployment

• kubectl create deploy <DEPLOY_NAME> --image <CONTAINER_IMAGE>
  • kubectl create deploy my-deploy --image nginx

Get the rollout status

• kubectl rollout status deploy <DEPLOY_NAME>
  • kubectl rollout status deploy my-deploy

Get the rollout history

• kubectl rollout history deploy <DEPLOY_NAME>
  • kubectl rollout history deploy my-deploy

Set image

• kubectl set image deploy <DEPLOY_NAME> <CONTAINER_NAME>=<IMAGE_NAME> --record
  • kubectl set image deploy my-deploy my-web-app=nginx --record the flag --record is optional, add it if you want to write the command executed in the resource annotation kubernetes.io/change-cause

Undo rollout

• kubectl rollout undo deploy <DEPLOY_NAME> --to-revision <REVISION_NUMBER>
  • kubectl rollout undo deploy my-deploy --to-revision 1 the flag --to-revision is optional, add it if you want to go to a specific revision

Services (svc)

Create a service (ClusterIP) from pod, this option use the pod labels as selectors

• kubectl expose pod <POD_NAME> --port <TARGET_PORT> --name <SERVICE_NAME>
  • kubectl expose pod my-pod --port 80 --name my-ci-service

Create a ClusterIP service

• kubectl create service clusterip <SERVICE_NAME> --tcp <CLUSTER_PORT>:<TARGET_PORT>
  • kubectl create service clusterip my-ci-service --tcp=80:8080

Create a NodePort service

• kubectl create service nodeport <SERVICE_NAME> --tcp <CLUSTER_PORT>:<TARGET_PORT> --node-port <NODE_PORT>
  • kubectl create service nodeport my-np-service --tcp 80:80 --node-port 30000

Namespaces (ns)

Create a new namespace

• kubectl create ns <NAMESPACE_NAME>
  • kubectl create ns my-namespace

Execute any command with a specific namespace

• <ANY_COMMAND> -n <NAMESPACE_NAME>
  • kubectl get pods -n my-namespace

Execute any command with all the namespaces

• <ANY_COMMAND> --all-namespaces
  • kubectl get pods --all-namespaces

Set namespace in the context

• kubectl config set-context $(kubectl config current-context) --namespace=<NAMESPACE_NAME>
  • kubectl config set-context $(kubectl config current-context) --namespace=my-ns

Configmaps (cm)

Create a new configmap from literals

• kubectl create cm <CONFIGMAP_NAME> --from-literal=<MY_KEY>=<MY_VALUE> --from-literal=<MY_KEY_2>=<MY_VALUE_2>
  • kubectl create cm my-configmap --from-literal=ANY_KEY=ANY_VALUE --from-literal=ANY_KEY_2=ANY_VALUE_2

Create a new configmap from a file

• kubectl create cm <CONFIGMAP_NAME> --from-file=<FILE_PATH>
  • kubectl create cm my-configmap --from-file=/tmp/configmap.properties

Secrets (secret)

Create a new secret from literals

• kubectl create secret generic <SECRET_NAME> --from-literal=<MY_KEY>=<MY_VALUE> --from-literal=<MY_KEY_2>=<MY_VALUE_2>
  • kubectl create secret generic my-secret --from-literal=ANY_KEY=ANY_VALUE --from-literal=ANY_KEY_2=ANY_VALUE_2

Create a new secret from a file

• kubectl create secret generic <SECRET_NAME> --from-file=<FILE_PATH>
  • kubectl create secret generic my-secret --from-file=/tmp/secrets.properties

Create a new TLS secret

• kubectl create secret tls <TLS_SECRET_NAME> --cert <CERT_PATH> --key <KEY_PATH>
  • kubectl create secret tls webhook-server-tls --cert "/root/keys/webhook-server-tls.crt" --key "/root/keys/webhook-server-tls.key"

Service Account (sa)

Create a new service account (this command also create a new secret for the service account)

• kubectl create sa <SERVICE_ACCOUNT_NAME>
  • kubectl create sa my-service-account

Taints

Associate a taint to a node

• kubectl taint node <NODE_NAME> <MY_KEY>=<MY_VALUE>:<TAINT_EFFECT>
  • kubectl taint node my-node my-key=my-value:NoSchedule

Taints effects:

• NoSchedule
• PreferNoSchedule
• NoExecute

delete a taint from a node

• kubectl taint node <NODE_NAME> <MY_KEY>-
  • kubectl taint node my-node my-key-

Node Selectors

Associate a label to a node

• kubectl label node <NODE_NAME> <MY_KEY>=<MY_VALUE>
  • kubectl label node my-node my-key=my-value

Jobs (job)

Create a new job

• kubectl create job <JOB_NAME> --image <IMAGE_NAME>
  • kubectl create job my-job --image busy-box

Cron-Jobs (cj)

Create a new job

• kubectl create cj <CRON_JOB_NAME> --schedule="<SCHEDULE_PATTERN>" --image <IMAGE_NAME>
  • kubectl create cj my-cron-job --schedule="1 * * * *" --image busy-box

Ingress

Create a new ingress resource

• kubectl create ingress <INGRESS_NAME> --rule <INGRESS_RULE>
• kubectl create ingress my-ingress --rule="foo.com/bar=svc1:8080,tls=my-cert"

Kube Config

Get current kube config

• kubectl config view
• kubectl config view

Set a Kube Config file

• kubectl config view --kubeconfig <MY_CUSTOM_CONFIG_PATH>
• kubectl config view --kubeconfig ~/Documents/kube-config.yml"

Get current context

• kubectl config current-context
• kubectl config current-context

Change context

• kubectl config use-context <CONTEXT_NAME>
• kubectl config use-context dev-user@development

Set credentials

• kubectl config set-credentials <USER_NAME> --client-certificate <CRT_PATH> --client-key <KEY_PATH>
• kubectl config set-credentials drogo --client-certificate /root/drogo.crt --client-key /root/drogo.key

role

create role

• kubectl create role <ROLE_NAME> --verb <VERB_NAME> --resource <RESOURCES_TO_BIND>
• kubectl create role developer --verb list,create,delete --resource pods
• Options:
  • Role for specific resource
    • kubectl create role <ROLE_NAME> --verb <VERB_NAME> --resource <RESOURCES_TO_BIND> --resourcename <RESOURCE_NAME>
    • kubectl create role developer --verb list,create,delete --resource pods --resourcename my-pod

rolebinding

create rolebinding

• kubectl create rolebinding <ROLEBINDING_NAME> --role <ROLE_NAME> --user <USER_NAME>
• kubectl create rolebinding dev-user:developer --role developer --user dev-user

clusterrole

create clusterrole

• kubectl create clusterrole <CLUSTER_ROLE_NAME> --verb <VERB_NAME> --resource <RESOURCES_TO_BIND>
• kubectl create clusterrole node-admin --verb get --resource nodes

clusterrolebinding

create rolebinding

• kubectl create clusterrolebinding <ROLEBINDING_NAME> --clusterrole <CLUSTER_ROLE_NAME> --user <USER_NAME>
• kubectl create clusterrolebinding dev-user:node-admin --clusterrole node-admin --user dev-user

AUTH

Check access

• kubectl auth can-i <ACTION_TO_VALIDATE>
• kubectl auth can-i create deployments

Options

Know how to create a definition file from an imperative command

• <IMPERATIVE_COMMAND> --dry-run=client -o <OUTPUT_FORMAT>
  • kubectl run nginx --image nginx --dry-run=client -o yaml

Know how to use any resource kubectl explain <RESOURCE_NAME> --recursive

• kubectl explain pods --recursive

Show the labels from any resource

• <KUBECTL_COMMAND> --show-labels
  • kubectl get pods --show-labels

Filter any resource by the label

• <KUBECTL_COMMAND> -l <MY_KEY_TO_FILTER>=<MY_VALUE_TO_FILTER>
  • kubectl get pods -l key=value

Get a list of api resources kubectl api-resources

• kubectl api-resources

Change API version of a yaml file kubectl convert -f <PATH_OLD_FILE> --output-version <NEW_VERSION>

• kubectl convert -f ingress-old.yaml --output-version networking.k8s.io/v1