36. GitHub Actions: automation with CI/CD

GitHub Actions: Automation with CI/CD

In a world where continuous software delivery has become a standard, GitHub Actions emerges as a powerful tool for automating the software development lifecycle. GitHub Actions makes it possible to implement continuous integration (CI) and continuous delivery (CD) pipelines directly in GitHub, providing an efficient way to automate testing, builds, deployment and any other type of workflow related to your project.

What are GitHub Actions?

GitHub Actions is a GitHub feature that allows the creation of customized workflows that are triggered by specific events within the repository, such as push, pull requests, tag creation, among others. These workflows are defined in YAML files and run in runners, which are execution environments provided by GitHub or self-hosted by users.

Main Components

• Workflows: Sequences of tasks that are executed in response to events in the repository.
• Events: Actions that trigger the execution of workflows, such as push or pull requests.
• Jobs: Sets of steps that are executed as part of a workflow.
• Steps: Individual tasks that make up a job. These can be shell commands or reusable actions.
• Actions: Reusable components that can be incorporated into the steps of a workflow.
• Runners: Servers that host the execution of workflows, which can be provided by GitHub or self-hosted.

How GitHub Actions for CI/CD Work

GitHub Actions allows developers to define a series of automated steps that will be performed each time code is pushed to the repository or when a pull request is created. These steps can include running automated tests, compiling code, and even deploying to production or staging environments.

Continuous Integration (CI)

Continuous integration is a development practice that involves frequently merging code into a shared repository. Each push is verified by an automated build and testing process, ensuring that changes to the code do not break the project. In GitHub Actions, this is accomplished through workflows that are triggered by events such as push or pull requests. Developers can configure the workflow to execute a series of commands that will compile code, run unit tests, integration tests, static code analysis, and more.

Continuous Delivery (CD)

Continuous delivery is the next step to continuous integration. After the code is integrated, it is automatically placed into a production or pre-production environment, ensuring that the software can be released at any time. In the context of GitHub Actions, this means setting up workflows that not only test and build code, but also deploy it. This may include updates to servers, cloud services, containers, serverless functions, among others.

Benefits of GitHub Actions for CI/CD

• Complete Automation: From integration to delivery, everything can be automated, reducing the need for manual intervention and increasing delivery speed.
• Customization: The possibility of creating personalized workflows that adapt to the specific needs of the project.
• Deep Integration with GitHub: As a native GitHub feature, Actions offers deep integration with other platform features, such as Issues and Pull Requests.
• Community and Marketplace: Access to a vast repository of community-developed Actions that can be reused to speed up workflow configuration.
• Scale: GitHub Actions automatically scales to meet project demands, and runners can be hosted on GitHub's infrastructure or on your own servers.

Example Workflow with GitHub Actions

Let's consider an example CI workflow that runs automated tests on every push or pull request to the main branch. The `.github/workflows/ci.yml` file could look something like:

name: Continuous Integration
on: [push, pull_request]
jobs:
  build-and-test:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v2
    - name: Set up Node.js
      uses: actions/setup-node@v1
      with:
        node-version: '14'
    - name:Install dependencies
      run: npm install
    - name: Run tests
      run: npm test
    

This workflow defines a job called build-and-test that will run in an Ubuntu environment. It starts by checking out the code, configures Node.js, installs the project's dependencies, and finally runs the tests.

Final Considerations

GitHub Actions is a robust and flexible tool that can significantly transform your software development workflow. With its customizability and deep integration with GitHub, it enables teams of any size to automate their CI/CD processes effectively, ensuring quality and speed in software delivery.