Kubernetes - Volumes 💾

Description 👀

Docker containers are meant to be transient in nature. They are meant to be created, used, and then destroyed. This is a great feature of containers, but it also presents a problem when it comes to state persistence. Just like in Docker the pods in Kubernetes are also transient. This means that if a pod is destroyed, all of its data is lost. This is a problem if you want to store data in a pod. To persist data in a pod you can use volumes. Volumes are a way to store data in a pod that will persist even if the pod is destroyed. Volumes are also a way to share data between pods.

Examples 🧩

• pod definition with a volume

  apiVersion: v1
  kind: Pod
  metadata:
      name: my-pod
  spec: 
      containers:
        - name: alpine
          image: alpine
          command: ["/bin/sh", "-c"]
          args: ["shuf -i 0-100 -n >> /opt/number.out"]
          volumeMounts:
            - mountPath: /opt
              name: data-volume
      volumes:
        - name: data-volume
          hostPath:
            path: /data
            type: Directory
  

• pod definition with a volume to be used in pvc section

  apiVersion: v1
  kind: Pod
  metadata:
    name: webapp
    namespace: default
  spec:
    containers:
      - name: event-simulator 
        image: kodekloud/event-simulator
        env:            
          - name: LOG_HANDLERS
            value: file
        volumeMounts:
          - mountPath: /log
            name: log-volume        
    volumes:
      - name: log-volume
        hostPath:
          path: /var/log/webapp
          type: Directory
  

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