GitHub Actions — GitHub's Native Automation Workflow

GitHub Actions — Actions Are Workflows

GitHub Actions is the CI/CD and automation platform GitHub launched in 2019. Like Gitlab CI, it belongs to the “repository-native CI” school — no need to stand up a separate CI server; drop a YAML file in the repository and it runs.

For developers who already host their code on GitHub, GitHub Actions is simply the most natural CI/CD choice.

Core Concepts

Workflow

A Workflow is an automation process, defined in a YAML file under the .github/workflows/ directory. A repository can have multiple Workflows.

Event

Workflows are triggered to run by events, for example:

• push: code is pushed
• pull_request: a PR is created/updated
• schedule: scheduled triggering (cron expression)
• workflow_dispatch: manual triggering

on:
  push:
    branches: [main]
  pull_request:
    branches: [main]
  schedule:
    - cron: '0 0 * * 1'  # every Monday at midnight

Job

A Workflow contains multiple Jobs. Jobs run in parallel by default, and you can also set dependency order. Each Job runs in its own isolated virtual environment.

Runner

A Runner is the machine that executes a Job. GitHub provides hosted Runners (Ubuntu, Windows, macOS), and you can self-host as well.

Action

An Action is the smallest reusable unit, similar to a function. You can use Actions shared by the community, or define your own.

A Typical Workflow

name: CI

on:
  push:
    branches: [main]
  pull_request:
    branches: [main]

jobs:
  build:
    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v4

      - name: Setup Node.js
        uses: actions/setup-node@v4
        with:
          node-version: '20'

      - name: Install dependencies
        run: npm ci

      - name: Run tests
        run: npm test

In just 20 short lines, it completes a full CI process: check out code → install Node.js → install dependencies → run tests.

GitHub Actions vs. Gitlab CI

GitHub Actions’ Unique Advantages

1. Marketplace — a Rich Action Ecosystem

There are tens of thousands of ready-made Actions on the Actions Marketplace, covering everything from deploying to AWS to sending Slack notifications to code quality checks. This turns building a pipeline into “stacking building blocks.”

2. Matrix Strategy

One line of configuration and you can test in parallel across multiple platforms and multiple versions:

strategy:
  matrix:
    os: [ubuntu-latest, windows-latest, macos-latest]
    node-version: [18, 20, 22]

This generates 3 × 3 = 9 parallel Jobs, covering every combination of operating system and Node.js version.

3. Automation Beyond CI/CD

GitHub Actions is not just CI/CD — it can be any kind of automation:

• Automatically labeling Issues
• Automatically publishing a Release after a PR is merged
• Scraping data on a schedule to update a repository
• Welcoming new Contributors

Afterword

The arrival of GitHub Actions gave CI/CD one more option. It isn’t out to replace anyone; it offers GitHub users a more “native” choice — no extra CI server to set up, and CI lives wherever the code is hosted.

It is the “last piece of the puzzle” in the GitHub ecosystem — code hosting + Issue tracking + PR review + Actions automation form a complete closed loop for development collaboration. As for whether to choose GitHub Actions, Jenkins or Gitlab CI, there’s no standard answer: use whatever fits where your code lives and what your team knows.

A small step forward every day is a new height!