5 steps to Deploy docker image to Kubernetes (FOR BEGINNERS UPDATED)

Introduction

This tutorial will guide you through the essential steps to deploy a Docker image to Kubernetes, aimed specifically at beginners. By following these steps, you will learn how to create a Dockerfile, build a Docker image, push it to Docker Hub, and finally, deploy it in a Kubernetes cluster.

Step 1: Prepare Your Environment

Before starting, ensure you have the following prerequisites:

• Docker installed and running on your laptop.
• A free Docker Hub account created.
• Git Bash installed to run Linux commands (for Windows users).
• Minikube installed on your laptop to create a local Kubernetes cluster.

Step 2: Create a Dockerfile

1. Open Git Bash or terminal.

2. Create a new folder for your Docker project:

   mkdir docker
   cd docker
   

3. Create a new file named Dockerfile:

   touch Dockerfile
   

4. Open the Dockerfile in a text editor (e.g., Vim):

   vi Dockerfile
   

5. Add the following lines to the Dockerfile:

   FROM nginx
   COPY index.html /usr/share/nginx/html/index.html
   

   • This line extends the existing Nginx image and overrides the default index.html file.

6. Save and exit the editor.

Step 3: Create the index.html File

1. Create an index.html file in the same directory:

   touch index.html
   

2. Open the file in a text editor:

   vi index.html
   

3. Add your desired content to index.html, then save and exit.

Step 4: Build the Docker Image

1. In the terminal, build your Docker image with the following command:

   docker build -t yourusername/nginx-demo:1.0 .
   

   • Replace yourusername with your Docker Hub username.
   • The . indicates the current directory.

2. After the image is built, you can verify it by running:

   docker images
   

Step 5: Push the Docker Image to Docker Hub

1. Log in to Docker Hub from the terminal:

   docker login
   

2. Push your newly created Docker image to Docker Hub:

   docker push yourusername/nginx-demo:1.0
   

3. Refresh Docker Hub to see your pushed image and its tags.

Step 6: Deploy the Docker Image in Minikube

1. Start Minikube if it’s not already running:

   minikube start
   

2. Create a Kubernetes pod using the following command:

   kubectl run demo-nginx --image=yourusername/nginx-demo:1.0 --port=80
   

3. Check the status of the pod:

   kubectl get pods
   

4. Create a service to expose the pod:

   kubectl expose pod demo-nginx --type=NodePort --port=80
   

5. Forward the service to access it from your laptop:

   kubectl port-forward service/demo-nginx 7080:80
   

Conclusion

You have successfully deployed a Docker image to Kubernetes. You learned how to create a Dockerfile, build and push a Docker image to Docker Hub, and deploy it as a pod in a local Kubernetes cluster. The next steps could involve exploring more advanced Kubernetes features or integrating your deployment into a CI/CD pipeline.