GitHub Actions - CI/CD Pipeline Basics

Basics of GitHub Actions

GitHub Actions is a powerful automation tool integrated into GitHub that allows you to create workflows for continuous integration and continuous deployment (CI/CD). Here are the basics of GitHub Actions along with the key technologies involved

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Basics of GitHub Actions

1. Workflows:

• A workflow is a defined automated process that runs one or more jobs. Workflows are specified in YAML files and reside in the .github/workflows/ directory of your repository.
• Workflows can be triggered by events like push, pull_request, or on a schedule.

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2. Events:

Events are specific activities that can trigger workflows. Common events include:

• push: Triggered when code is pushed to the repository.
• pull_request: Triggered when a pull request is opened or updated.
• schedule: Triggered at scheduled times (using cron syntax).
• release: Triggered when a release is published.

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3. Jobs:

• A job is a set of steps that execute on the same runner. Jobs can run in parallel or sequentially depending on dependencies.
• Each job is defined under a jobs key in the workflow file and can specify a runs-on key to define the type of runner (e.g., ubuntu-latest, windows-latest).

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4. Steps:

• A step is an individual task that runs as part of a job. Steps can run commands, call actions, or execute scripts.
• Steps are executed in order and can use actions to perform common tasks.

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5. Actions:

• Actions are reusable units of code that can be called from workflows to perform tasks. You can use actions created by GitHub, the community, or create custom actions.
• Actions are available in the GitHub Marketplace, allowing you to integrate third-party tools easily.

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6. Runners:

A runner is a server that runs your jobs. GitHub provides hosted runners (Linux, Windows, macOS) or you can self-host runners if you need specific configurations or environments.

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7. Secrets and Environment Variables:

• Secrets are sensitive data (like API keys, tokens) stored securely in GitHub and can be referenced in workflows. They ensure that sensitive information is not exposed in logs.
• Environment variables can be set in workflows to pass data between jobs or steps.

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Key Technologies Involved

1. YAML:

Workflows are defined using YAML syntax, a human-readable data serialization standard. Understanding YAML structure is essential for creating and modifying workflows.

2. Docker:

GitHub Actions can run in Docker containers, allowing you to create custom environments or run actions in isolated settings.

3. GitHub API:

GitHub Actions can interact with the GitHub API to manage repositories, issues, pull requests, and other GitHub resources programmatically.

4. Node.js / JavaScript:

Many actions are built using JavaScript and Node.js, especially for custom actions that need to perform specific tasks.

5. CI/CD Tools:

GitHub Actions can integrate with various CI/CD tools and platforms, allowing you to build, test, and deploy applications seamlessly. Common integrations include AWS, Azure, Docker, Heroku, and more.

6. Containerization:

You can create Docker-based actions, enabling you to package your action code and dependencies in a container, ensuring consistent execution across environments.

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Conclusion

GitHub Actions provides a flexible and powerful framework for automating software development workflows. Understanding the basics of workflows, jobs, steps, actions, and runners, along with the key technologies involved, is essential for leveraging GitHub Actions effectively in CI/CD processes. This allows developers to automate testing, deployment, and various other tasks, improving efficiency and collaboration within teams.