Kubernetes Cluster Maintenance

Upgrading the Kubernetes Cluster

Upgrading a Kubernetes cluster is crucial to ensure it remains secure, stable, and up-to-date with the latest features. Follow these steps to upgrade your Minikube cluster,

Check Current Version,
- First, verify the current version of your Minikube and Kubernetes using the following commands,

minikube version
kubectl version

Stop Minikube,
- Before upgrading, stop the Minikube cluster,

minikube stop

Upgrade Minikube,
- Upgrade Minikube to the latest version,

curl -LO https://storage.googleapis.com/minikube/releases/latest/minikube-linux-amd64
sudo install minikube-linux-amd64 /usr/local/bin/minikube

Start Minikube with a New Kubernetes Version,
- Start Minikube with a specific or latest Kubernetes version,

minikube start --kubernetes-version=<Put_Latest_Version>

verify upgrade status,

minikube version
kubectl version

As we already on latest version of minikube, hence not able to upgrade to latest.

Backing Up and Restoring Data

Backing up and restoring data ensures that your cluster's state can be preserved and recovered in case of failure or migration.

Backup

Backup Kubernetes Resources:
- Use kubectl to export all resources in a namespace (e.g., notes-app) to YAML files:
```
  kubectl get all --n notes-app -o yaml > notes-app-backup.yml
```

Backup Persistent Volumes:
- Back up the data stored in Persistent Volumes. If you’re using hostPath, copy the data to a secure location:
```
  # Example: assuming the data is stored in /mnt/data
  tar czvf pv-backup.tar.gz /mnt/data
```
Store Backups Securely:
- Ensure that your backups are stored securely, either on a remote server or cloud storage.

Restore

Restore Kubernetes Resources:
- Restore the Kubernetes resources from the YAML backup:
```
  kubectl apply -f notes-app-backup.yaml
```
Restore Persistent Volumes:
- Restore the data to the Persistent Volumes:
```
  tar xzvf pv-backup.tar.gz -C /mnt/data
```
Verify Restoration:
- Ensure that the restored resources and data are functioning correctly by checking the status of the pods and services:
```
  kubectl get pods --namespace=notes-app
  kubectl get services --namespace=notes-app
```