> For the complete documentation index, see [llms.txt](https://freundcloud.gitbook.io/devops-examples-from-real-life/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://freundcloud.gitbook.io/devops-examples-from-real-life/should-learn/tools/kubectl.md).

# kubectl

`kubectl` is the primary command-line tool for interacting with Kubernetes clusters. It allows you to deploy applications, inspect and manage cluster resources, and view logs. Mastery of `kubectl` is essential for DevOps engineers working with AWS EKS, Azure AKS, GCP GKE, NixOS, and WSL environments.

***

## Installation

**macOS (Homebrew):**

```bash
brew install kubectl
```

**Linux (Debian/Ubuntu):**

```bash
sudo apt-get update && sudo apt-get install -y kubectl
```

**NixOS (declarative):**\
Add to your `/etc/nixos/configuration.nix`:

```nix
environment.systemPackages = with pkgs; [ kubectl ];
```

Then run:

```sh
sudo nixos-rebuild switch
```

**Windows (WSL):**\
Install via Chocolatey or manually download the binary from the [official docs](https://kubernetes.io/docs/tasks/tools/).

***

## Quick Reference: Common kubectl Commands

### Cluster Management

* `kubectl cluster-info` – Show cluster endpoints
* `kubectl version` – Show client/server versions
* `kubectl config view` – Show kubeconfig
* `kubectl get all --all-namespaces` – List all resources in all namespaces

### Resource Listing

* `kubectl get namespaces` – List all namespaces
* `kubectl get pods` – List all pods in current namespace
* `kubectl get pods -o wide` – Detailed pod info
* `kubectl get pods --field-selector=spec.nodeName=<node>` – Pods on a node
* `kubectl get rc,services` – List replication controllers and services

### Deployments & Rollouts

* `kubectl get deployment` – List deployments
* `kubectl describe deployment <name>` – Deployment details
* `kubectl edit deployment <name>` – Edit deployment
* `kubectl create deployment <name> --image=<image>` – Create deployment
* `kubectl delete deployment <name>` – Delete deployment
* `kubectl rollout status deployment <name>` – Rollout status
* `kubectl rollout history deployment/<name>` – Rollout history
* `kubectl rollout undo deployment/<name>` – Rollback deployment
* `kubectl rollout restart deployment/<name>` – Restart deployment

### Pods

* `kubectl get pod` – List pods
* `kubectl describe pod <name>` – Pod details
* `kubectl logs <pod>` – Pod logs
* `kubectl logs -f <pod>` – Follow logs
* `kubectl exec -it <pod> -- /bin/sh` – Shell into pod
* `kubectl delete pod <name>` – Delete pod

### Namespaces

* `kubectl create namespace <name>` – Create namespace
* `kubectl get namespace` – List namespaces
* `kubectl describe namespace <name>` – Namespace details
* `kubectl delete namespace <name>` – Delete namespace

### Nodes

* `kubectl get nodes` – List nodes
* `kubectl describe node <name>` – Node details
* `kubectl cordon <node>` – Mark node unschedulable
* `kubectl drain <node>` – Prepare node for maintenance
* `kubectl uncordon <node>` – Mark node schedulable
* `kubectl top node` – Node resource usage

### DaemonSets

* `kubectl get daemonset` – List daemonsets
* `kubectl describe ds <name> -n <namespace>` – DaemonSet details
* `kubectl edit daemonset <name>` – Edit DaemonSet
* `kubectl delete daemonset <name>` – Delete DaemonSet

### Events

* `kubectl get events` – List events
* `kubectl get events --field-selector type=Warning` – List warnings

### Logs

* `kubectl logs <pod>` – Pod logs
* `kubectl logs -c <container> <pod>` – Container logs
* `kubectl logs --since=1h <pod>` – Last hour logs
* `kubectl logs --tail=20 <pod>` – Last 20 lines
* `kubectl logs --previous <pod>` – Previous pod logs

### Services & Service Accounts

* `kubectl get services` – List services
* `kubectl describe service <name>` – Service details
* `kubectl expose deployment <name>` – Expose as service
* `kubectl get serviceaccounts` – List service accounts
* `kubectl describe serviceaccount <name>` – Service account details

### Secrets

* `kubectl create secret generic <name> --from-literal=key=value` – Create secret
* `kubectl get secrets` – List secrets
* `kubectl describe secret <name>` – Secret details
* `kubectl delete secret <name>` – Delete secret

***

## Real-World DevOps Example: Rolling Update

```bash
kubectl set image deployment/myapp myapp=nginx:1.25.0
kubectl rollout status deployment/myapp
kubectl rollout undo deployment/myapp
```

***

## Best Practices

* Use `kubectl --context` and `--namespace` to avoid mistakes in multi-cluster/multi-namespace environments
* Use `kubectl explain <resource>` to discover resource fields
* Use `kubectl apply -f <file.yaml>` for declarative resource management
* Integrate `kubectl` with CI/CD (GitHub Actions, Azure Pipelines, GitLab CI)
* Use [kubectx/kubens](https://github.com/olafkfreund/wiki/blob/main/pages/should-learn/kubernetes/kubectx-or-kubens.md) for fast context/namespace switching
* Never run destructive commands (`delete`, `drain`) without double-checking the context/namespace

***

## References

* [kubectl Cheat Sheet (Kubernetes.io)](https://kubernetes.io/docs/reference/kubectl/cheatsheet/)
* [kubectl Official Docs](https://kubernetes.io/docs/reference/generated/kubectl/)
* [kubectl on NixOS](https://search.nixos.org/packages?channel=unstable\&show=kubectl)

> **Tip:** Use shell aliases and prompt tools (e.g., kube-ps1) to display current context/namespace and avoid costly mistakes.