List of most important commands

Assumption: Use of kas alias for kubectrl

Generic

  • List names of all resources: k api-resources
  • List resources in default namespace: k get RESOURCE_TYPE
  • List resources in specified namespace: k get RESOURCE_TYPE -n NAMESPACE
  • List resources in all namespaces: k get RESOURCE_TYPE -A

  • List resources by selectors: k get RESOURCE_TYPE --selector KEY1=VALUE1,KEY2=VALUE2

  • List all resources: k get all

  • List all resources in all namespaces: k get all -A

  • Describe resource k describe RESOURCE_NAME

  • Create definition file of existing resource: k get RESOURCE_TYPE RESOURCE_NAME -o yaml > FILENAME.yaml

  • Create resource with existing definition file: k create -f FILENAME.yaml

  • Edit exisiting resource: k edit RESOURCE_TYPE RESOURCE_NAME

  • Repace existing resource: k replace --force -f FILENAME.yaml

  • Update label on a resource: k label RESOURCE_TYPE RESOURCE_NAME KEY=VALUE

  • Get logs of resource: k logs RESOURCE_NAME
    • RESOURCE_NAME: POD_NAME or service/SERVICE_NAME
  • Display resources usage: k top RESOURCE_TYPE
    • Needs a running metrics server
    • Run a metrics server: k apply -f https://github.com/kubernetes-sigs/metrics-server/releases/latest/download/components.yaml
  • Operators: In, NotIn, Exists, DoesNotExist

Pods

  • Create Pod: k run POD_NAME --image=IMAGE_NAME
  • Create definition file for Pod: k run POD_NAME --image=IMAGE_NAME --dry-run=client -o yaml > FILENAME.yaml

ReplicaSets

  • Up/Down-Scale: k scale --replicas=NEW_NUMBER rs/RS_NAME

Deployment

  • Create deployment with replicas: k create deploy DEPLOYMENT_NAME --image=IMAGE_NAME --replicas=NUMBER

Namespaces

  • Switch permanently to namespace: k config set-context $(k config current-context) --namespace=NAMESPACE

Services

  • Expose a service for a Pod: k expose pod POD_NAME --port=PORT --name=SRV_NAME
  • Create a Pod and expose a service (same name): k run POD_NAME --image=IMAGE_NAME --port=PORT --expose=true

Docker images

  • Create: docker build -t IMAGE_NAME PATH_TO_DOCKERFILE
  • Run an instance: docker run -p EXPOSED_PORT:APP_PORT IMAGE_NAME
  • Run command in instance: docker run IMAGE_NAME cat /etc/*release*

Taints and toleration

  • Effects: NoSchedule, NoExecute, PreferNoSchedule

  • Create taint on node: k taint nodes NODE_NAME KEY=VALUE:EFFECT
  • Delete taint from node: k taint nodes NODE_NAME KEY-