CI/CD Pipeline with Docker: Getting Started with GitHub Actions

Introduction: CI/CD Pipeline with Docker and GitHub Actions 🚀

CI/CD pipelines automate the process of integrating, testing, and deploying code changes, making software delivery faster and more reliable. By combining Docker’s containerization capabilities with GitHub Actions, developers can streamline their workflows directly within GitHub.

In this blog, we’ll briefly guide you through setting up a CI/CD pipeline using Docker and GitHub Actions, enabling you to automate builds, tests, and deployments for your projects with ease. Let’s get started!

Table of Content

• 📘 What is GitHub actions ?
• 🔄 What Are Those Workflows?
• 🚀 Why another CI/CD tool : Benefits of GitHub actions
• 📈 Why Is the Setup Easier?
• ⚙️ CI/CD with GitHub actions setup
• 🛠️ Modify the YAML File and Commit Changes
• ✅ Verifying the Success of the Process
• 🎯 Conclusion

📘 Introduction to GitHub Actions

GitHub Actions is a powerful feature of GitHub that allows you to automate, customize, and execute software development workflows directly in your repository. It integrates seamlessly into your development lifecycle and supports Continuous Integration/Continuous Deployment (CI/CD) processes, among other automation tasks.

🔄 What Are Those Workflows?

Developers often face tasks that are time-consuming and tedious, which is why automation is essential. For example, when using GitHub, many developers upload their open-source projects, allowing the community to utilize, contribute to, and enhance these projects. This includes adding new features, submitting pull requests, and more.

When working on organizational tasks, such as reporting a bug in a repository, creating an issue, submitting a pull request to address that issue, and merging the fix into the master branch of the project, the workflow can become highly tedious. To simplify and automate these processes, GitHub Actions were created.

📈 Why Is the Setup Easier?

When you think about a CI/CD pipeline, one of the most important aspects is integrating with various tools.

In the above process, you need to configure everything manually, such as installing Java, Maven, and Docker, as well as configuring plugins. This can be cumbersome and time-consuming.

Instead, you might prefer a simpler way, where you can specify an environment that already includes tools like Docker and Node.js, with specific versions, without needing to install or configure them yourself. By simply connecting to the target environment, you can deploy your application with ease.

This process we create docker image and push into docker hub.

🔹 First, create a new repository on GitHub and then push the relevant files from your project to it. In this guide, I will demonstrate using a Java project with Gradle (you can use any type of project you prefer)

Then you can start automating your tasks under the github actions.

🔹 Go to the inside that repository select Github Actions on top.Now your’re on github actions section and select appropriate automation type that matching your project type (Java, Python, Docker, …etc). In this situation i will use to “Java with Gradle”



🔹 Then click the Configure button on that it will open under workflow folder pre configured ymal file.

🛠️ Modify the YAML File and Commit Changes

In this scenario, we made modifications to certain parts of the YAML file to ensure that the GitHub Action setup is configured correctly. Additionally, we added essential configurations required for the workflow to run as expected.

🔹 Updated YMAL file as follows,

name: Java CI with Gradle

on: 
  push:
    branches: [ master ]
  pull_request:
    branches: [ master ]

jobs:
  build-java:
    runs-on: ubuntu-latest

    steps:
    - uses: actions/checkout@v2

    - name: Set up JDK 1.8
      uses: actions/setup-java@v1
      with:
        java-version: 1.8

    - name: Grant execute permission for gradlew
      run: chmod +x gradlew

    - name: Build with Gradle
      run: ./gradlew build

    - name: Build and Push Docker Image
      uses: mr-smithers-excellent/docker-build-push@v4
      with:
        image: sasankaranawaka/githubactions
        registry: docker.io
        username: ${{ secrets.DOCKER_USERNAME }}
        password: ${{ secrets.DOCKER_PASSWORD }}

  

In above code snippet added at the end new part as,

    - name: Build and Push Docker Image
      uses: mr-smithers-excellent/docker-build-push@v4
      with:
        image: sasankaranawaka/githubactions
        registry: docker.io
        username: ${{ secrets.DOCKER_USERNAME }}
        password: ${{ secrets.DOCKER_PASSWORD }}

This code snippet is added at the end of the YAML file because it performs the final step in the workflow: building and pushing the Docker image to the Docker registry. It relies on earlier steps, like building and testing the application, to complete successfully before running

This code snippet uses secret keys (DOCKER_USERNAME and DOCKER_PASSWORD) to authenticate with the Docker registry securely. These keys are stored in the repository’s Secrets settings in GitHub, ensuring sensitive information like login credentials is not exposed directly in the workflow file.

Steps to Add Secrets in GitHub:

1. Go to the Settings tab of your repository.
2. Select Secrets and variables → Actions.
3. Click New repository secret.
4. Add secrets:
   • Name: DOCKER_USERNAME, Value: Your Docker Hub username.
   • Name: DOCKER_PASSWORD, Value: Your Docker Hub password or access token.
5. Save the secrets.

Accessing Secrets in the Workflow

Once added, the workflow accesses these secrets using ${{ secrets.DOCKER_USERNAME }} and ${{ secrets.DOCKER_PASSWORD }} during the docker-build-push step. This ensures secure and automated deployments.

🔹 Next step is log into your Docker hub and create a new repository for push this docker image(The image part added your Docker hub new repository name)

🔹 So,“Finally, after clicking the ‘Commit changes’ button to save, you can see under the Actions tab that the YAML file is being updated.”

✅ Verifying the Success of the Process

After clicking the Commit Changes button, the YAML file will be updated. This triggers the workflow to create a Docker image based on the specified configurations in the file. The Docker image is then pushed to the newly created repository in Docker Hub.

Steps to Verify:

1. Wait for the GitHub Actions workflow to complete.
2. Go to your Docker Hub account.
3. Refresh the Repositories tab in Docker Hub.
4. Look for the newly pushed Docker image from the workflow.

🎯Conclusion

In today’s fast-paced development world, automation is not optional—it’s essential. CI/CD bridges the gap between development and deployment by ensuring that code is tested, integrated, and released in a reliable, repeatable way.

GitHub Actions makes it incredibly easy to implement CI/CD directly within your GitHub repositories, without the need for external tools. Whether you’re building small personal projects or managing production-level applications, adopting CI/CD practices with GitHub Actions will help you deliver faster, reduce errors, and improve your overall workflow.

Start small, automate one thing at a time—and soon, you’ll wonder how you ever worked without it.