# Day 36- Mastering Persistent Volumes in Your Kubernetes Deployment 🌐💾  (Jan 01, 2024)

Introduction:

Congratulations on reaching Day 36 of the #90DaysOfDevOps Challenge! Yesterday, we delved into the realms of ConfigMaps and Secrets in Kubernetes, enhancing our understanding of managing configuration data and secrets securely. Today, our focus shifts to Persistent Volumes (PVs) and how they play a crucial role in managing storage in a Kubernetes cluster.

### What are Persistent Volumes in Kubernetes?

In Kubernetes, a **Persistent Volume (PV)** represents a piece of storage provisioned by an administrator in the cluster. It acts as a storage resource that can be dynamically or statically provisioned. A **Persistent Volume Claim (PVC)**, on the other hand, is a user's request for storage. The PVC references a PV, and once bound, the PV is associated with a specific node.

### Task 1: Adding a Persistent Volume to Your Deployment

#### 1\. Create a Persistent Volume:

Create a Persistent Volume using a file on your node. Here's a template for `pv.yml`:

```plaintext
apiVersion: v1
kind: PersistentVolume
metadata:
  name: todo-app-pv
spec:
  capacity:
    storage: 1Gi
  volumeMode: Filesystem
  accessModes:
    - ReadWriteOnce
  hostPath:
    path: "/your/local/path"
```

Replace `/your/local/path` with the desired local path on your node.

#### 2\. Create a Persistent Volume Claim:

Create a Persistent Volume Claim using a file. Here's a template for `pvc.yml`:

```plaintext
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: todo-app-pvc
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 1Gi
```

#### 3\. Update Deployment YAML to Include the Persistent Volume Claim:

Modify your `deployment.yml` file to include the Persistent Volume Claim. Add the following snippet under `spec.template.spec.containers`:

```plaintext
volumeMounts:
  - name: todo-app-storage
    mountPath: "/path/in/container"
```

#### 4\. Apply the Updated Deployment:

Execute the following command to apply the updated deployment:

```plaintext
kubectl apply -f deployment.yml
```

#### 5\. Verify the Persistent Volume:

Check the status of Pods and Persistent Volumes:

```plaintext
kubectl get pods
kubectl get pv
```

### Task 2: Accessing Data in the Persistent Volume

#### 1\. Connect to a Pod:

Use the following command to connect to a Pod in your Deployment:

```plaintext
kubectl exec -it <pod-name> -- /bin/bash
```

#### 2\. Verify Access to Data:

Inside the Pod, verify that you can access the data stored in the Persistent Volume.