How To Use Docker Desktop To Deploy Kubernetes Clusters ?

Docker Desktop has revolutionized local development environments by seamlessly integrating Kubernetes, a powerful container orchestration platform. This article gives an idea of how to use Docker Desktop to deploy Kubernetes clusters, which also includes step-by-step instructions and troubleshooting advice. This thorough instruction will enable you to fully utilize Kubernetes on your local system, regardless of your level of experience with containerization.

Understanding Docker Desktop And Kubernetes Integration

Docker Desktop has a standalone Kubernetes server and client that is integrated with the Docker CLI. It facilitates the deployment of Kubernetes clusters directly on your local machine, eliminating the need for external resources during development and testing. The Kubernetes server within Docker Desktop is a single-node cluster running within a Docker container, designed for local testing and deployment.

Deploying Kubernetes Clusters With Docker Desktop

The following are the steps to deploy a Kubernetes cluster with a Docker Desktop:

Step 1: Verifying Docker Desktop Installation

• To ensure Docker Desktop is installed correctly, open a terminal or command prompt and run.
• This command should display information about the installed Docker version.

docker version

Step 2: Enabling Kubernetes In Docker Desktop

• Open the Docker Dashboard.
• Select “Settings” from the left sidebar.
• Navigate to the “Kubernetes” tab.
• Check the “Enable Kubernetes” checkbox.
• Click “Apply & Restart” to save settings and then select “Install” to instantiate the required images for the Kubernetes server.

Step 3: Verifying Kubernetes Installation

• Check the Kubernetes installation by running the `kuberbetes version`.
• This command should display the Kubernetes client and server version, indicating a successful installation.

kubectl version

Step 4: Deploying A Sample Application

• Create a YAML file, `sample-deployment.yaml`, with the following contents:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: sample-app
spec:
  replicas: 3
  selector:
    matchLabels:
      app: sample-app
  template:
    metadata:
      labels:
        app: sample-app
    spec:
      containers:
        - name: sample-container
          image: nginx:latest
          ports:
            - containerPort: 80

• Apply the deployment to the Kubernetes cluster:

kubectl apply -f sample-deployment.yaml

Step 5: Checking Deployment Status

Monitor the kubernetes deployment status with:

kubectl get pods

Step 6: Accessing The Deployed Application

• Retrieve the external IP address of the deployed application:

kubectl get svc

Access the application in a web browser using the provided external IP address.

Exploring Docker Desktop’s Kubernetes Features

Docker Desktop offers several features to enhance the Kubernetes development experience. The following are the some of the features of Docker Desktop’s Kubernetes:

1. Dashboard Integration

• Access the Kubernetes dashboard with following kubectl command:

kubectl dashboard

• The dashboard provides a graphical interface for managing and visualizing your clusters.

2. Resource Management

• Adjust resource allocation for your Kubernetes cluster from Docker Desktop settings, specifying the number of CPUs and the amount of memory.

3. Kubernetes Context Switching

• Switch between different Kubernetes contexts:

kubectl config get-contexts
kubectl config use-context <context-name>

• This is useful when working with multiple clusters.

Understanding The Kubernetes With Docker Desktop

1. Kubernetes Components: Docker Desktop integrates with Kubernetes, managing components such as the API server, controller manager, scheduler, and etcd, all encapsulated within Docker containers.

2. kubectl Command Usage: Docker Desktop provides the Kubernetes CLI command at `/usr/local/bin/kubectl` on Mac and `C:\Program Files\Docker\Docker\Resources\bin\kubectl.exe` on Windows.

kubectl get nodes

• Ensure that `kubectl` points to the Docker Desktop context:

kubectl config use-context docker-desktop

• Expected output shall be similar to: Switched to context “docker-desktop”.

3. Accessing Kubernetes Dashboard: Open the Kubernetes dashboard to visualize and manage your clusters:

kubectl dashboard

4. Upgrading Kubernetes Cluster: Docker Desktop does not automatically upgrade your Kubernetes cluster. To upgrade, select “Reset Kubernetes Cluster” in the Docker Dashboard.

Deploying A Sample Voting Application

Let’s deploy a more complex application – the classic Docker sample voting app – to further explore Docker Desktop’s capabilities.

Step 1: Enable Kubernetes In Docker Desktop

• Navigate to Docker Desktop settings.
• Click on “Kubernetes”
• Check the “Enable Kubernetes” checkbox.

Step 2: Verify Kubernetes Cluster

• Check the state of your Docker Desktop cluster with the following command.

kubectl get nodes

Step 3: Run The Voting App

• Deploy the sample voting app:

kubectl apply -f https://raw.githubusercontent.com/docker/docker-birthday/master/resources/kubernetes-docker-desktop/vote.yaml

Step 4: Check App Components

• Check the pods for the voting app with the following command:

kubectl -n vote get pods

Step 5: Use the App

• Access the voting app in your browser at http://localhost:5000
• Vote for Cats or Dogs, and check the results at http://localhost:5001

Step 6: Check Resilience

• Test Kubernetes’ resilience by removing a container with following command.
• Observe that Kubernetes replaces the removed container.

docker container rm -f $(docker container ls -f name='k8s_result*' --format '{{.ID}}')

Step 7: Teardown Your Environment

Reset your Kubernetes cluster and remove the demo app:

• Open Docker Desktop settings.
• Click on “Kubernetes.”
• Click the “Reset Kubernetes Cluster” button.

Conclusion

In this extensive guide, we’ve explored how Docker Desktop simplifies the deployment of Kubernetes clusters on local machines. From enabling Kubernetes to deploying a sample application and troubleshooting common issues, this guide equips you with the knowledge to seamlessly integrate Docker Desktop into your Kubernetes development workflow. With additional insights into Kubernetes components, `kubectl` commands, and a hands-on deployment of a sample voting app, you now have a comprehensive understanding of leveraging Docker Desktop for Kubernetes development. Happy coding!

Troubleshooting Common Issues

1. Check System Requirements: Ensure your machine meets Docker Desktop and Kubernetes’ minimum system requirements in terms of OS compatibility and hardware specifications.

2. Restart Docker Desktop: Restart Docker Desktop to resolve minor issues with the following command: docker

 desktop restart

3. Verify Kubernetes Configuration: Double-check the Kubernetes configuration in Docker Desktop settings and review any error messages or warnings.

4. Update Docker Desktop: Regularly update Docker Desktop and Kubernetes to address bugs and security vulnerabilities.

 docker desktop update

Docker Desktop’s Kubernetes – (FAQs)

What Is Docker Desktop, And Why Would I Use It For Kubernetes Development?

Docker Desktop is a tool that simplifies the deployment of Kubernetes clusters on local machines. It provides a standalone Kubernetes server, client integration with Docker CLI, and numerous features like dashboard integration and resource management. Using Docker Desktop for Kubernetes development streamlines the local testing of containerized applications, making it an ideal solution for developers.

How Does Docker Desktop Manage Kubernetes Clusters On A Local Machine?

Docker Desktop includes a standalone Kubernetes server that runs within a Docker container on the local machine. This server is a single-node cluster, specifically designed for local testing. The integration allows users to enable or disable Kubernetes from the Docker Desktop settings, providing a straightforward way to manage and deploy containerized workloads.

Can I Run Kubernetes Workloads Alongside Docker Swarm And Standalone Containers Using Docker Desktop?

Yes, turning on Kubernetes in Docker Desktop allows you to deploy your workloads in parallel, supporting Kubernetes, Docker Swarm, and standalone containers. This flexibility enables developers to seamlessly switch between different container orchestration platforms based on their project requirements.

How Does Docker Desktop Handle Upgrades For The Kubernetes Cluster?

Docker Desktop does not automatically upgrade the Kubernetes cluster after a new update. To upgrade your Kubernetes cluster to the latest version, users need to manually select the “Reset Kubernetes Cluster” option in the Docker Desktop settings. This ensures that users have control over when and how their Kubernetes cluster gets updated.

How To Turn Off And Uninstall Kubernetes?

To turn off Kubernetes in Docker Desktop go to the Docker Dashboard, select the Settings icon then select Kubernetes from the left sidebar. Next to Enable Kubernetes, clear the checkbox then select Apply & Restart to save the settings. This stops and removes Kubernetes containers, and also removes the `/usr/local/bin/kubectl` command.