| Pods | Description |
|---|---|
kubectl completion --help |
To search for "enabling completion" |
source <(kubectl completion bash) |
To enable completion for kubectl |
kubectl api-resources |
To list out shortname for resources |
kubectl get pods |
Get information about running pods in current namespace |
kubectl describe pod |
Describe one pod |
kubectl expose pod --port=444 --name=frontend |
Expose the port of a pod (creates a new service) |
kubectl port-forward 8080 |
Port forward the exposed pod port to your local machine |
kubectl attach -i |
Attach to the pod |
kubectl exec -- command |
Execute a command on the pod |
kubectl exec -it pod-name bash |
SSH onto the pod |
kubectl label pods mylabel=awesome |
Add a new label to a pod |
kubectl run -i --tty busybox --image=busybox --restart=Never -- sh |
Run a shell in a pod - very useful for debugging |
| Parameters | Description |
|---|---|
--all-namespaces |
To display resource in all namespaces |
-l LABEL-NAME |
To filter for a specific LABEL-NAME |
-l LABEL-NAME1,LABEL-NAME2 |
For filtering pods that has specific label names |
--sort-by=metadata.creationTimestamp |
To sort the Pods by age |
--output=yaml |
To dusplay output in YAML format |
--o yaml |
To dusplay output in YAML format, can also use JSON |
--wide |
To dusplay more information in the output |
--show-labels |
show labels attached to those pods |
kubectl create is what we call Imperative Management. On this approach you tell the Kubernetes API what you want to create, replace or delete, not how you want your K8s cluster world to look like.
Example:
kubectl create deployment my-deployment --image=nginxkubectl apply is part of the Declarative Management approach, where changes that you may have applied to a live object (i.e. through scale) are "maintained" even if you apply other changes to the object.
Example:
kubectl apply -f my-manifest.yaml The main difference is that if the resource exists, kubectl create will error out and kubectl apply will not error out.
| Deployments | Description |
|---|---|
kubectl get deployments |
Get information on current deployments |
kubectl get rs |
Get information about the replica sets |
kubectl rollout status deployment/helloworld-deployment |
Get deployment status |
kubectl set image deployment/helloworld-deployment k8s-demo=k8s-demo |
Run k8s-demo with the image label version 2 |
kubectl edit deployment/helloworld-deployment |
Edit the deployment object |
kubectl rollout status deployment/helloworld-deployment |
Get the status of the rollout |
kubectl rollout history deployment/helloworld-deployment |
Get the rollout history |
kubectl rollout undo deployment/helloworld-deployment |
Rollback to previous version |
kubectl rollout undo deployment/helloworld-deployment --to-revision=n |
Rollback to any version version |