Kubernetes commands

A lot of people struggle with the adoption of Kubernetes particularly moving from Infrastructure operations background, myself included. Following on from last post titled Kubernetes Explained , I have had some exposure with Kubernetes in my current role and want to share some common commands to query a Kubernetes cluster.

  • Create a resource from a file (Kubernetes works with file types of .yml, .yaml and .json ) 
kubectl apply -f ./my_file.yaml

  • List all pods in the namespace
kubectl get pods

  • Get the documentation for pod manifests 
kubectl explain pods

  • List all services in the namespace: 
kubectl get services

  • List all pods in all namespaces: 
kubectl get pods --all-namespaces
  • List all pods in a namespace with the labelled APP1: 
kubectl get pods -l APP1
  • List all pods in the current namespace, with more details 
 kubectl get pods -o wide

List all pods sorted by status of restart count 

kubectl get pods --sort-by="{.status.containerStatuses[:1].restartCount}"

List a particular deployment 

  kubectl get deployment [deployment name]

  • List a particular namespace 
 kubectl get ns [namespace name]

  • List all running pods in namespace

kubectl get pods –field-selector=status.phase=Running

  • Get YAML of a pod
kubectl get pod [pod name] -o yaml

  • Describe command displays pod/ node details with verbose output 
kubectl describe pods [pod name]
kubectl describe nodes  [pod name]

  • Delete a pod 
kubectl delete pod [pod name]

  • Delete a node 
kubectl delete node [node name]

  • Mark my-node as unschedulable 
kubectl cordon my-node
  • Drain a node 
kubectl drain [node name]

  • Mark my-node as schedulable 
kubectl uncordon [node name]

  • List Events sorted by timestamp 
kubectl get events --sort-by=.metadata.creationTimestamp

  • Dump pod logs (stdout) 
kubectl logs [pod name]

  • Scale a replicaset named ‘AAA’ to 3 replicas 
kubectl scale --replicas=3 rs/AAA

  • If the deployment named XYZ’s current size is 2, scale XYZ to 3 
kubectl scale --current-replicas=2 --replicas=3 deployment/XYZ

  • Show metrics for a given pod and its containers 
kubectl top pod [pod name] --containers

  • Show metrics for a given pod and sort it by ‘cpu’ or ‘memory’ 
kubectl top pod [pod name] --sort-by=cpu