Kubernetes Volume Mounts: Sharing Data

Kubernetes is an open-source container orchestration technology that automates the manual work of deploying, managing, and scaling containerized applications. In Kubernetes, the containers are isolated from one another, so many containers can run on the same machine without interrupting anybody else. It enables the deployment and management of container-based applications across a Kubernetes cluster of machines.

What are Kubernetes Volume Mounts?

Kubernetes volume mounts are the most important thing that lets containers have persistent storage. They transfer data between containers and survive if the pod is rescheduled or moved. You can also manage volumes with Docker CLI commands or the Docker API. This works in Linux and Windows containers, which means it can be distributed much more reliably over several containers.

Example of Volume Mounts in a Pod Specification

apiVersion: v1
kind: Pod
metadata:
  name: mypod
spec:
  containers:
  - name: mycontainer
    image: myimage
    volumeMounts:
    - mountPath: /data
      name: my-storage
      readOnly: false
  volumes:
  - name: my-storage
    emptyDir: {}

How Do Kubernetes Volume Mounts Work?

• Kubernetes storage is based on volume mounts, a volume mount is an abstraction storage unit that containers can use to store and share data between themselves.
• A pod describes which volumes to access and where to arrange them in its containers.
• The data in a volume mount lasts longer than the containers running in the pod, which can shut down and resume as ephemeral units.
• Because a container crash is not enough to disconnect a pod from a node, in the case of a container crash, data in volumes remain intact.
• By utilizing storage claims to indicate the kind of storage needed, cluster nodes can request mounts of volumes.

Implementation of Kubernetes Volume Mounts: Sharing Data

Here is the step-by-step procedure for Kubernetes Volume Mounts: Sharing Data:

Step 1: Create the Volume

First, Select the volume type that best suits your needs. This could be an emptyDir for temporary storage, a PersistentVolume for persistent storage, or another kind.

kubectl apply -f my-pv.yaml

Output:

Step 2: Make a Pod

Next, Specify the deployment or pod that will use the volume. Provide the mount path and volume in the Pod specification.

apiVersion: v1
kind: Pod
metadata:
  name: mypod
spec:
  containers:
  - name: mycontainer
    image: myimage
    volumeMounts:
    - mountPath: /data
      name: my-storage
  volumes:
  - name: my-storage
    persistentVolumeClaim:
      claimName: my-pvc

Step 3: Verify Pod Status

You should verify your YAML configuration files with the kubectl command.

kubectl get pods

Output:

Step 4: Apply the Configuration

Then you must use kubectl to apply the YAML configuration files.

kubectl describe pod mypod

Output:

Step 5: Manage and Monitor Volumes

After that, you can manage and monitor volumes to containers for sharing data.

kubectl describe pvc my-pvc

Output:

Step 6: Verify the Deployment

Lastly, you have to verify that your deployment is correctly utilizing the volume by checking its status.

kubectl get deployments

Output:

Real-world scenarios of Kubernetes Volume Mounts: Sharing Data

• Configuration refresh: Some applications may demand a live reload of the configuration without restarting the entire pod.
• Shared functionality: Some workloads can benefit from sharing storage rather than delivering data asynchronously across the network. For example, if you have an image, music, or video upload microservice.
• Initialization step: Several open-source programs now offer auto-generating self-signed TLS certificates.
• Exporter sidecars: The main application can log to a file, whereas a sidecar container can stream data from a shared volume and send it to a centralized logging infrastructure.

Conclusion

In this article, we have learned about Kubernetes Volume Mounts: Sharing Data. Kubernetes Volume Mounts provides pods with persistent storage. Volume mounts are an abstraction layer that Kubernetes utilizes to give containers shared storage and are just mountable folders on pods.