Demystifying CI/CD: Simplify Your Web Development Workflow with GitHub Actions and Docker

Streamlining the web development process is a full-time job. From testing to deployment, every step in the workflow requires intentionality and precision. That’s where Continuous Integration and Continuous Delivery (CI/CD) come in. By automating testing, building, and deployment processes, CI/CD can make your development workflow more efficient, error-free, and ultimately more productive.

In this tutorial, we’ll explore how to integrate GitHub Actions and Docker into your web development workflow. GitHub Actions automates workflows, while Docker ensures the consistent performance of your applications. The combination of both can significantly increase your productivity and reduce errors.

Why Use GitHub Actions and Docker?

GitHub Actions is a tool that automates workflow processes, from code testing to deployment. It integrates seamlessly with your Git repository to execute workflow tasks based on specific events, such as code pushes or pull requests. It can also build, test, and deploy your code directly in GitHub.

Docker, on the other hand, is a tool that simplifies containerization. Containerization is the process of spinning up a virtual environment that includes your code, dependencies, and runtime environment. By creating containers, you can ensure the consistency of your application’s performance across different computers and operating systems.

Combining GitHub Actions with Docker makes your workflow even smoother. Using GitHub Actions to automate your workflow, you can define specific steps to build, test, and deploy your code using Docker. This can save you time and reduce the chances of errors significantly.

Setting Up GitHub Actions for Your Workflow

To set up GitHub Actions for your workflow, start by creating a workflow file in your repository. The file should be created in the .github/workflows folder. You can name the file anything you want, but it should have a .yml extension. Here’s an example:


name: CI/CD Pipeline with Docker
on:
  push:
    branches: [ main ]
jobs:
  build:
    runs-on: ubuntu-latest

    steps:
    - uses: actions/checkout@v2

    - name: Building Docker Container
      uses: docker/build-push-action@v2
      with:
        context: .
        push: false
        tags: my-container:${{ github.sha }}

  test:
    runs-on: ubuntu-latest

    steps:
    - name: Running Docker Container
      uses: docker://my-container:${{ github.sha }}
      with:
        entrypoint: "/bin/sh -c"
        args:
          - "npm test"

In this example, two steps are defined: build and test. The first step builds a Docker container from the current repository and tags it with a unique identifier. The second step executes the test scripts inside the Docker container.

Using Docker Containers in Your Workflow

Now that you’ve set up GitHub Actions for your workflow, let’s see how you can use Docker containers to ensure the consistency of your applications. Docker containers work by virtualizing the operating system, ensuring that it remains constant across different machines. To use Docker, you’ll need to have Docker installed on your machine. (See the Docker documentation for installation instructions.)

To get started with Docker, create a Dockerfile in your repository. This file describes the environment your application needs to run, including dependencies, languages, frameworks, and other tools. Here’s an example:


FROM node:14-alpine
WORKDIR /app
COPY . .
RUN npm i
CMD ["npm", "start"]

This Dockerfile builds an image from the official Node.JS image on Docker Hub. It sets the work directory to /app, copies the files in the app directory, installs dependencies, and runs the npm start command. With this Dockerfile, you can create a Docker container that includes Node.JS and all its dependencies, ready to run your app.

Once you have a Dockerfile, you can build an image and spin up the container. To build the Docker image, open your terminal and navigate to the root directory of your project. Then, run this command:


docker build -t my-container .

The -t flag tags your image with the name my-container. The period at the end of the command specifies that the build context is the current directory. Once the command completes, you’ll have an image of your application that you can spin up as many containers as you need.

Now that you’ve built your Docker image, you can spin up a container to start testing and running your application. To start the container and run your application, run this command in your terminal:


docker run my-container

This will start a new container instance of my-container and begin running your application inside the container. You can test your application from your local machine or connect to the container using a web browser or command-line tool.

Conclusion

Integrating GitHub Actions and Docker into your workflow can make your work more efficient, less prone to error, and more productive. With GitHub Actions, you can define specific steps to automate the build, test and deploy processes. With Docker, you can ensure the consistency of your application’s performance across different computers and operating systems. The combination of both tools can significantly increase your productivity and reduce errors.

If you’re new to CI/CD, there can be a bit of a learning curve, but once you get the hang of it, it becomes second nature. With some experimentation and practice, you’ll see how beneficial it can be to your development workflow.