**Intro**: Marko Luksa’s *Kubernetes in Action* is still a gem for learning Kubernetes. But the thing about Kubernetes is—it never sits still. Some of the commands in the book have already gone out of style. Here’s my cheat sheet of updated commands to keep things working with the latest Kubernetes versions. **Original vs. Updated Commands** - **kubectl get rc** **Old way**: `kubectl get rc` **New way**: `kubectl get replicaset` or `kubectl get rs` **What changed**: ReplicationControllers (rc) have been replaced by ReplicaSets (rs). - **kubectl scale rc** **Old way**: `kubectl scale rc --replicas=` **New way**: `kubectl scale replicaset --replicas=` —or just do it via Deployment: `kubectl scale deployment --replicas=` - **kubectl delete rc** **Old way**: `kubectl delete rc ` **New way**: `kubectl delete replicaset ` —but honestly, it’s better to manage things with Deployments now. Managing with Deployments keeps all the related resources (ReplicaSet, Pod, etc.) in sync with your desired state. Less fiddling, fewer surprises. - **kubectl rolling-update** **Old way**: `kubectl rolling-update --image=` **New way**: Deprecated. Use Deployments for rolling updates now. The rolling update dance is all handled by Deployments—more powerful, more “let me just declare it and go get coffee.” For example: ``` kubectl set image deployment/my-deployment my-container=my-image:tag ``` or ``` kubectl rollout status deployment/my-deployment ``` The best part: zero downtime, and automatic rollback if things go sideways. - **kubectl run** **Old way**: ``` kubectl run --image= ``` **New way**: Usually, you just create a Pod directly, or (more commonly) use a Deployment to manage your Pods. **Commands That Still Work Just Fine** - **kubectl create namespace** **Old way**: `kubectl create ns ` **New way**: Still works. If you want to be explicit: ``` kubectl create namespace ``` - **kubectl exec** **Old way**: ``` kubectl exec -- ``` **New way**: Still alive and kicking. No change needed. - **kubectl proxy** **Old way**: `kubectl proxy` **New way**: Still valid, still widely used. Nothing to update. - **kubectl expose** **Old way**: `kubectl expose rc --port=` **New way**: `kubectl expose replicaset --port=` or more often, expose a Deployment or Service directly. - **kubectl autoscale** **Old way**: `kubectl autoscale rc ` **New way**: `kubectl autoscale deployment --min= --max= --cpu-percent=` - **kubectl create** **Old way**: `kubectl create -f .yaml` **New way**: These days, `kubectl apply -f .yaml` is the go-to for idempotency. **Other Useful Commands** - **kubectl annotate**: Add or update annotations on a resource. - **kubectl cluster-info**: Show cluster information. - **kubectl logs**: Get container logs from a Pod. - **kubectl port-forward**: Forward local ports to a Pod. - **kubectl describe**: Display detailed resource info. - **kubectl patch**: Patch resources on the fly. - **kubectl replace**: Replace a resource by applying new config—though `kubectl apply` is usually better. - **kubectl edit**: Edit resources directly on the server. - **kubectl rollout status**: Check Deployment rollout status. - **kubectl set image**: Update container images in a Deployment. - **kubectl create configmap**: Create a ConfigMap from files, directories, or literals. - **kubectl create secret**: Create a Secret from files, directories, or literals. - **kubectl cp**: Copy files and directories to or from containers. **Notes & Suggestions** - ReplicationControllers (rc) are totally out; ReplicaSets (rs) are in and managed via Deployments. - The old imperative style (`kubectl create`) is giving way to a more declarative approach (`kubectl apply`)—much less “oops, did I miss something?”. - Rolling updates and resource management now run through Deployments and StatefulSets. Forget `kubectl rolling-update`. - Bottom line: always use Deployments and StatefulSets for managing Pod lifecycle, scaling, and updates. It just fits with how Kubernetes wants you to do things these days.