What are Service Containers

Service containers in GitHub Actions let you spin up Docker containers alongside your workflow jobs, providing on-demand services—such as databases, caches, or message queues—for your CI/CD pipelines. By defining services in your workflow YAML, you can run integration and end-to-end tests without managing external infrastructure.

Basic Workflow Without Service Containers

The simplest workflow runs tests immediately after code checkout and dependency installation. It’s ideal for unit tests that don’t require external services.

name: My Awesome App
on: push

jobs:
  unit-testing:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout Code
        uses: actions/checkout@v3

      - name: Set Up Node.js
        uses: actions/setup-node@v3
        with:
          node-version: '20'

      - name: Install Dependencies
        run: npm install

      - name: Run Tests
        run: npm test

This workflow is perfect for fast-running unit tests that do not depend on external databases or caches. If your tests require a service, see the next section.

Adding a MongoDB Service Container

To test against a MongoDB database, add a services section. This example maps the container’s default MongoDB port to a host port on the runner:

name: My Awesome App
on: push

jobs:
  unit-testing:
    runs-on: ubuntu-latest

    services:
      mongodb-service:
        image: mongo:latest
        ports:
          - 12345:27017

    steps:
      - name: Checkout Code
        uses: actions/checkout@v3

      - name: Set Up Node.js
        uses: actions/setup-node@v3
        with:
          node-version: '20'

      - name: Install Dependencies
        run: npm install

      - name: Run Tests
        run: |
          export MONGODB_HOST=localhost
          export MONGODB_PORT=12345
          npm test

Here’s what happens:

Service Container: mongo:latest runs as mongodb-service.
Port Mapping: Container port 27017 is mapped to runner port 12345.
Environment Variables: Tests connect to localhost:12345.

Common Service Containers for CI Workflows

Service	Description	Docker Image
MongoDB	NoSQL document database	`mongo:latest`
PostgreSQL	Relational SQL database	`postgres:13`
Redis	In-memory cache	`redis:6`
MySQL	Widely-used SQL database	`mysql:8`

Be mindful of resource limits on GitHub-hosted runners. Running multiple heavyweight services can lead to slower startup times or timeouts.

Running Steps Inside a Job Container with Services

You can isolate your build environment by specifying a job container and still link to service containers through the Docker network:

name: My Awesome App
on: push

jobs:
  unit-testing:
    runs-on: ubuntu-latest

    container:
      image: ghcr.io/node-and-packages:20

    services:
      mongodb-service:
        image: mongo:latest

    env:
      MONGODB_HOST: mongodb-service
      MONGODB_PORT: 27017

    steps:
      - name: Checkout Code
        uses: actions/checkout@v3

      - name: Install Dependencies
        run: npm install

      - name: Run Tests
        run: npm test

Key points:

Job Container runs every step inside ghcr.io/node-and-packages:20.
Service Container mongodb-service is discoverable on the default Docker bridge network.
Networking uses the service container’s hostname (mongodb-service) without port mapping.

Links and References

Watch Video

What are Job Containers

Run Unit Testing Job using a Service

Introduction

GitHub Actions - Core Concepts

Continuous Integration with GitHub Actions

Continuous Deployment with GitHub Actions

Reusable Workflows and Reporting

Custom Actions

Self Hosted Runner

Security Guide

GitHub Actions in the Enterprise Cloud

What are Service Containers

Basic Workflow Without Service Containers

Adding a MongoDB Service Container

Common Service Containers for CI Workflows

Running Steps Inside a Job Container with Services

Links and References

Watch Video

​Basic Workflow Without Service Containers

​Adding a MongoDB Service Container

​Common Service Containers for CI Workflows

​Running Steps Inside a Job Container with Services

​Links and References

Watch Video

Basic Workflow Without Service Containers

Adding a MongoDB Service Container

Common Service Containers for CI Workflows

Running Steps Inside a Job Container with Services

Links and References