GitHub Actions

Overview

migetpacks integrates with GitHub Actions to build and push container images as part of your CI/CD pipeline. It works with both self-hosted runners (recommended for performance) and GitHub-hosted runners.

Self-Hosted Runner

Self-hosted runners offer the best performance because Docker layer caches and package manager caches persist between builds.

name: Build with migetpacks

on:
  push:
    branches: [main]

jobs:
  build:
    runs-on: self-hosted

    steps:
      - uses: actions/checkout@v4

      - name: Log into registry
        uses: docker/login-action@v3
        with:
          registry: your-registry.io
          username: ${{ secrets.REGISTRY_USERNAME }}
          password: ${{ secrets.REGISTRY_PASSWORD }}

      - name: Setup cache directory
        run: mkdir -p /home/runner/migetpacks-cache

      - name: Build with migetpacks
        run: |
          docker run --rm \
            -v ${{ github.workspace }}:/workspace/source:ro \
            -v /var/run/docker.sock:/var/run/docker.sock \
            -v /home/runner/migetpacks-cache:/cache \
            -e OUTPUT_IMAGE=your-registry.io/app:${{ github.sha }} \
            -e BUILD_CACHE_DIR=/cache \
            -e REGISTRY_MIRROR=https://registry.example.io/mirror \
            -e USE_DHI=true \
            miget/migetpacks:latest

The persistent cache directory (/home/runner/migetpacks-cache) survives runner restarts and dramatically speeds up dependency installation on subsequent builds.

GitHub-Hosted Runner

GitHub-hosted runners do not persist Docker layer caches between runs. Use CACHE_IMAGE for registry-based caching to speed up builds.

name: Build with migetpacks

on:
  push:
    branches: [main]
  pull_request:

jobs:
  build:
    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v4

      - name: Log into registry
        uses: docker/login-action@v3
        with:
          registry: your-registry.io
          username: ${{ secrets.REGISTRY_USERNAME }}
          password: ${{ secrets.REGISTRY_PASSWORD }}

      - name: Build with migetpacks
        run: |
          docker run --rm \
            -v ${{ github.workspace }}:/workspace/source:ro \
            -v /var/run/docker.sock:/var/run/docker.sock \
            -e OUTPUT_IMAGE=your-registry.io/app:${{ github.sha }} \
            -e CACHE_IMAGE=your-registry.io/app:buildcache \
            -e CACHE_MODE=max \
            miget/migetpacks:latest

Configuration Options

Always authenticate before running migetpacks if you are pushing to a private registry:

- name: Log into Docker Hub
  uses: docker/login-action@v3
  with:
    username: ${{ secrets.DOCKERHUB_USERNAME }}
    password: ${{ secrets.DOCKERHUB_TOKEN }}

- name: Log into GHCR
  uses: docker/login-action@v3
  with:
    registry: ghcr.io
    username: ${{ github.actor }}
    password: ${{ secrets.GITHUB_TOKEN }}

- name: Log into ECR
  uses: docker/login-action@v3
  with:
    registry: 123456789.dkr.ecr.us-east-1.amazonaws.com
    username: ${{ secrets.AWS_ACCESS_KEY_ID }}
    password: ${{ secrets.AWS_SECRET_ACCESS_KEY }}

Build Cache Directory

BUILD_CACHE_DIR enables shared package manager caching. On self-hosted runners, point this to a persistent directory:

- name: Setup cache directory
  run: mkdir -p /home/runner/migetpacks-cache

- name: Build with migetpacks
  run: |
    docker run --rm \
      -v /home/runner/migetpacks-cache:/cache \
      -e BUILD_CACHE_DIR=/cache \
      ...

Registry Mirror

REGISTRY_MIRROR configures a pull-through cache for Docker Hub images, reducing image pull times:

-e REGISTRY_MIRROR=https://your-mirror.example.com

Custom Environment Variables

Pass build-time environment variables directly:

- name: Build with migetpacks
  run: |
    docker run --rm \
      -v ${{ github.workspace }}:/workspace/source:ro \
      -v /var/run/docker.sock:/var/run/docker.sock \
      -e OUTPUT_IMAGE=your-registry.io/app:${{ github.sha }} \
      -e NODE_OPTIONS="--max-old-space-size=4096" \
      -e NEXT_PUBLIC_API_URL="${{ vars.API_URL }}" \
      -e RAILS_MASTER_KEY="${{ secrets.RAILS_MASTER_KEY }}" \
      miget/migetpacks:latest

Secrets like RAILS_MASTER_KEY are injected as build-time environment variables and will be present in the generated Dockerfile. They are visible in the final image’s environment. Use runtime secrets injection for sensitive values in production.

Full Workflow Example

This complete workflow builds on push to main, tags with both commit SHA and latest, and uses all available caching strategies:

name: Build and Push

on:
  push:
    branches: [main]

jobs:
  build:
    runs-on: self-hosted

    steps:
      - uses: actions/checkout@v4

      - name: Log into registry
        uses: docker/login-action@v3
        with:
          registry: your-registry.io
          username: ${{ secrets.REGISTRY_USERNAME }}
          password: ${{ secrets.REGISTRY_PASSWORD }}

      - name: Setup persistent cache
        run: mkdir -p /home/runner/migetpacks-cache

      - name: Build with migetpacks
        run: |
          docker run --rm \
            -v ${{ github.workspace }}:/workspace/source:ro \
            -v /var/run/docker.sock:/var/run/docker.sock \
            -v /home/runner/migetpacks-cache:/cache \
            -e OUTPUT_IMAGE=your-registry.io/app:${{ github.sha }} \
            -e BUILD_CACHE_DIR=/cache \
            -e CACHE_IMAGE=your-registry.io/app:buildcache \
            -e CACHE_MODE=max \
            -e REGISTRY_MIRROR=https://registry.example.io/mirror \
            -e USE_DHI=true \
            miget/migetpacks:latest

Performance Tips

Self-Hosted
GitHub-Hosted

Persistent cache: Use BUILD_CACHE_DIR pointed at a local directory
Pre-pull images: Pull common base images during runner initialization
Registry mirror: Use REGISTRY_MIRROR for Docker Hub images
Local Docker cache: Docker layer cache persists in /var/lib/docker
NVMe storage: Use local SSD/NVMe for /var/lib/docker instead of network storage

Registry cache: Use CACHE_IMAGE with CACHE_MODE=max for best cache hits
Additional sources: Use CACHE_FROM to read from multiple cache images
Smaller images: Use USE_DHI=true for distroless runtime images

Getting Started

Guides

Configuration

Languages

Deploying

Reference

Overview

Self-Hosted Runner

GitHub-Hosted Runner

Configuration Options

Build Cache Directory

Registry Mirror

Custom Environment Variables

Full Workflow Example

Performance Tips

​Overview

​Self-Hosted Runner

​GitHub-Hosted Runner

​Configuration Options

​Registry Login

​Build Cache Directory

​Registry Mirror

​Custom Environment Variables

​Full Workflow Example

​Performance Tips

Overview

Self-Hosted Runner

GitHub-Hosted Runner

Configuration Options

Registry Login

Build Cache Directory

Registry Mirror

Custom Environment Variables

Full Workflow Example

Performance Tips