Tutorial Presentation on CI/CD with GitHub Actions

This content originally appeared on DEV Community and was authored by Goodluck Ekeoma Adiole

1. Introduction to CI/CD

• Continuous Integration (CI):

  • A software development practice where developers frequently merge code changes into a shared repository.
  • Automated builds and tests are run to detect integration issues early.
  • Benefits: faster feedback, reduced integration problems, improved collaboration.

• Continuous Delivery (CD):

  • Extends CI by automatically preparing code for release to production.
  • Ensures software can be deployed reliably at any time.
  • Deployment can be manual but is always ready.

• Continuous Deployment (CD – extended form):

  • Goes a step further: every change that passes all pipeline stages is automatically deployed to production.
  • Requires very high confidence in automated testing and monitoring.

2. Why CI/CD is Important

• Speeds up software development lifecycle (SDLC).
• Ensures high-quality code through automated testing.
• Reduces deployment risks and downtime.
• Promotes collaboration between developers, operations, and security teams (DevOps/DevSecOps).
• Enables faster innovation while maintaining stability.

3. Popular CI/CD Tools (Brief Overview)

• Jenkins: Open-source automation server, highly customizable with plugins.
• GitLab CI/CD: Integrated with GitLab repositories, offers built-in pipelines.
• CircleCI: Cloud-based CI/CD tool with container-native workflows.
• Azure DevOps Pipelines: Microsoft solution with strong integration to Azure services.
• Travis CI: Well-known CI/CD platform integrated with GitHub (mostly for open-source).
• GitHub Actions: Native CI/CD for GitHub repositories, deeply integrated into the GitHub ecosystem.

(Next sections will focus deeply on GitHub Actions.)

4. Introduction to GitHub Actions

• A CI/CD platform built directly into GitHub.
• Automates workflows across software development lifecycle: build, test, deploy.
• Event-driven: workflows can be triggered by repository events (push, pull request, release).
• Uses YAML configuration files stored in .github/workflows/.

Key Benefits:

• Native GitHub integration.
• Free usage with GitHub-hosted runners (with limitations).
• Support for self-hosted runners (for more control).
• Large marketplace of prebuilt actions.

5. Core Concepts of GitHub Actions

1. Workflows

• Automated processes defined in .yml files.
• Example: “Run tests on every push.”

1. Events

• Triggers that start workflows.
• Examples: push, pull_request, schedule, workflow_dispatch.

1. Jobs

• A set of steps executed on the same runner.
• Can run sequentially or in parallel.

1. Steps

• Individual tasks inside a job.
• Each step can run commands or actions.

1. Actions

• Reusable units of code packaged for specific tasks.
• Examples: checkout code, set up Node.js, deploy to AWS.

1. Runners

• Virtual machines that execute workflows.
• Options: GitHub-hosted (Linux, Windows, macOS) or self-hosted.

6. Workflow Lifecycle in GitHub Actions

1. Developer pushes code to GitHub.
2. Trigger event activates the workflow.
3. Workflow runner executes jobs as defined.
4. Steps run sequentially within each job.
5. Jobs may run in parallel or depend on each other.
6. Results (logs, artifacts, test results) are reported in GitHub UI.
7. (Optional) Deployment to staging/production occurs.

7. Typical CI/CD Workflow with GitHub Actions

Continuous Integration Workflow

• Trigger: push or pull_request.

• Jobs:

  • Checkout code.
  • Install dependencies.
  • Run static analysis (linting, code quality checks).
  • Run unit/integration tests.
  • Build artifacts.

Continuous Delivery Workflow

• Trigger: Merge into main or tagged release.

• Jobs:

  • Build Docker image or application package.
  • Run security scans.
  • Deploy to staging environment.
  • (Optional) Await manual approval for production release.

Continuous Deployment Workflow

• Same as delivery, but automatically deploys to production after successful tests.

8. Best Practices for GitHub Actions

• Use caching (e.g., dependencies) to speed up workflows.
• Separate workflows for CI (test/build) and CD (deployment).
• Use secrets management (GitHub Secrets) for credentials.
• Set branch protection rules to enforce CI checks before merging.
• Reuse actions from the Marketplace to save time.
• Keep workflows modular and readable.
• Monitor logs and set up alerts for failed workflows.

9. Advantages of GitHub Actions over Other Tools

• Direct integration with GitHub repositories (no external setup).
• Easy YAML configuration and readability.
• Access to GitHub ecosystem (Marketplace, APIs).
• Free tier sufficient for many small to medium projects.
• Supports both simple and complex workflows.
• Good balance of flexibility and ease of use compared to Jenkins or GitLab CI.

10. Example Use Cases

1. CI Only: Run tests and lint checks for every pull request.
2. CD to Cloud: Deploy app to AWS, Azure, or GCP after successful tests.
3. Security Automation: Run vulnerability scans with Dependabot or custom security actions.
4. Scheduled Jobs: Nightly builds, automated backups, or dependency updates.
5. Custom DevOps Pipelines: Integrate with Docker, Kubernetes, or Terraform.

11. Challenges & Considerations

• Limited free minutes and storage (for large projects, consider self-hosted runners).
• YAML syntax errors can break workflows—needs careful review.
• May require external integrations for advanced deployment strategies.
• Security risks if secrets are not managed properly.

12. Conclusion

• CI/CD is essential for modern software delivery, improving quality and speed.
• GitHub Actions provides a powerful, integrated, and user-friendly platform for CI/CD directly within GitHub.
• By understanding workflows, jobs, steps, and runners, teams can build robust automation pipelines.
• Adoption of best practices ensures secure, efficient, and scalable software delivery pipelines.

This content originally appeared on DEV Community and was authored by Goodluck Ekeoma Adiole