migetpacks

Auto-detecting buildpacks for container images - automatically detects your language, version, and builds optimized container images using official upstream Docker images.

Built by miget.com - Unlimited apps, one price.

Features

Zero Config - Automatically detects language, version, and builds your app
14 Languages - Node.js, Deno, Bun, Python, Ruby, Go, Rust, Java, Kotlin, Scala, Clojure, .NET, PHP, Elixir
Secure by Default - Optional Docker Hardened Images (distroless, CVE-free)
Multi-Buildpack - Combine languages (e.g., Ruby + Node.js for asset compilation)
Procfile Support - Standard process definitions
Non-root Runtime - All containers run as non-root user
Fast Builds - BuildKit layer caching and registry-based caching

Requirements

Docker Desktop (macOS/Windows) or Docker Engine (Linux)
BuildKit enabled (default in Docker Desktop 4.0+)

migetpacks runs Docker-in-Docker using BuildKit for optimized multi-stage builds. It requires access to the Docker socket (/var/run/docker.sock).

# Verify Docker is running
docker info

# Verify BuildKit is available
docker buildx version

Quick Start

Docker

# Build your app
docker run --rm \
  -v /path/to/your/app:/workspace/source \
  -v /var/run/docker.sock:/var/run/docker.sock \
  -e OUTPUT_IMAGE=my-app:latest \
  miget/migetpacks:latest

# Run your app
docker run -p 5000:5000 my-app:latest

GitHub Actions (GitHub-hosted runners)

For ephemeral ubuntu-latest runners, use registry-based caching via CACHE_IMAGE:

name: Build and Push

on:
  push:
    branches: [main]

jobs:
  build:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write

    steps:
      - uses: actions/checkout@v4

      - name: Log in to GitHub Container Registry
        uses: docker/login-action@v3
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      # Required for CACHE_IMAGE support
      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

      - name: Build and push with migetpacks
        run: |
          docker run --rm \
            -v ${{ github.workspace }}:/workspace/source:ro \
            -v /var/run/docker.sock:/var/run/docker.sock \
            -v /home/runner/.docker/config.json:/root/.docker/config.json:ro \
            -e OUTPUT_IMAGE=ghcr.io/${{ github.repository }}:${{ github.sha }} \
            -e CACHE_IMAGE=ghcr.io/${{ github.repository }}:cache \
            miget/migetpacks:latest

GitHub Actions (Self-hosted runners)

For persistent self-hosted runners, use local file cache via BUILD_CACHE_DIR:

name: Build and Push

on:
  push:
    branches: [main]

jobs:
  build:
    runs-on: self-hosted

    steps:
      - uses: actions/checkout@v4

      - name: Log in to registry
        uses: docker/login-action@v3
        with:
          registry: registry.example.com
          username: ${{ secrets.REGISTRY_USERNAME }}
          password: ${{ secrets.REGISTRY_PASSWORD }}

      - name: Build and push with migetpacks
        run: |
          docker run --rm \
            -v ${{ github.workspace }}:/workspace/source:ro \
            -v /var/run/docker.sock:/var/run/docker.sock \
            -v $HOME/.docker/config.json:/root/.docker/config.json:ro \
            -v /var/cache/migetpacks:/cache \
            -e OUTPUT_IMAGE=registry.example.com/my-app:${{ github.sha }} \
            -e BUILD_CACHE_DIR=/cache \
            miget/migetpacks:latest

Cache options:

CACHE_IMAGE - Registry-based BuildKit layer cache. Requires docker/setup-buildx-action. Works on ephemeral runners.
BUILD_CACHE_DIR - Local directory for package manager caches (npm, pip, bundler, etc.). Best for persistent self-hosted runners.

Supported Languages

Language	Detection	Version Source
Node.js	`package.json`	`.nvmrc`, `.node-version`, `package.json`
Deno	`deno.json`, `deno.jsonc`	`deno.json`
Bun	`bun.lockb`, `bunfig.toml`	`package.json`
Python	`requirements.txt`, `Pipfile`, `pyproject.toml`	`.python-version`, `runtime.txt`
Ruby	`Gemfile`	`.ruby-version`, `Gemfile`
Go	`go.mod`	`go.mod`
Rust	`Cargo.toml`	`Cargo.toml`
PHP	`composer.json`, `index.php`	`composer.json`
Java	`pom.xml`, `build.gradle`	`pom.xml`, `.java-version`, `system.properties`
Kotlin	`build.gradle.kts`	`system.properties`
Scala	`build.sbt`	`system.properties`
Clojure	`project.clj`, `deps.edn`	`system.properties`
.NET	`.csproj`, `.fsproj`	`global.json`, `*.csproj`
Elixir	`mix.exs`	`mix.exs`, `.elixir-version`
Dockerfile	`Dockerfile`	-
Compose	`compose.yaml`, `docker-compose.yml`	-

Environment Variables

Variable	Required	Default	Description
`OUTPUT_IMAGE`	Yes	-	Target image name (e.g., `ghcr.io/user/app:tag`)
`SOURCE_DIR`	No	`/workspace/source`	Source code directory
`LANGUAGE`	No	auto-detected	Force language (see values below)
`RUN_COMMAND`	No	from Procfile	Override the run command
`PORT`	No	`5000`	Application port
`ARCH`	No	`x86_64`	Target architecture (`x86_64`, `arm64`)
`PROJECT_PATH`	No	-	Subdirectory for monorepo builds
`BUILDPACKS`	No	auto-detected	Explicit buildpack order (e.g., `ruby,nodejs`)
`DOCKERFILE_PATH`	No	-	Custom Dockerfile path (forces `dockerfile` language)
`COMPOSE_FILE`	No	-	Custom compose file path (forces `compose` language)
`TAG_LATEST`	No	`false`	Also tag image with `:latest` in addition to primary tag
`RESULT_FILE`	No	-	Path to write build results JSON
`STORAGE_DRIVER`	No	`overlay2`	Docker storage driver (e.g., `fuse-overlayfs` for nested DinD)

Caching Options

Variable	Required	Default	Description
`CACHE_IMAGE`	No	-	Registry image for BuildKit cache
`CACHE_MODE`	No	`min`	BuildKit cache export mode: `min` (final layer) or `max` (all layers)
`CACHE_FROM`	No	-	Additional read-only cache sources (comma-separated registry refs)
`CACHE_REGISTRY_INSECURE`	No	`false`	Set to `true` for HTTP registries
`NO_CACHE`	No	`false`	Force fresh build, skips cache-from
`BUILD_CACHE_DIR`	No	-	Directory for package manager cache
`REGISTRY_MIRROR`	No	-	Docker registry mirror URL

Docker Hardened Images

Variable	Required	Default	Description
`USE_DHI`	No	`false`	Use Docker Hardened Images from dhi.io
`DHI_USERNAME`	No	-	DHI registry username (alternative to mounting docker config)
`DHI_PASSWORD`	No	-	DHI registry password/token
`DHI_MIRROR`	No	-	DHI registry mirror URL

External Private Registry

When the app's Dockerfile pulls a base image from a private registry (e.g. FROM private.example.com/team/base-image:tag), set these vars on the app to log the builder in before the build runs. Same names as documented at docs.miget.com/deployments/registry-credentials. Read directly from the environment, or extracted from BUILD_VARS (the JSON envelope the platform uses to ship app vars into the build).

Variable	Required	Default	Description
`EXTERNAL_REGISTRY_URL`	No	-	Registry host (e.g. `docker.io`, `ghcr.io`, `registry.digitalocean.com`, `<account>.dkr.ecr.<region>.amazonaws.com`)
`EXTERNAL_REGISTRY_USERNAME`	No	-	Username/token name for the registry login
`EXTERNAL_REGISTRY_PASSWORD`	No	-	Password / read-only access token (recommended)

Custom Build Environment Variables

Any environment variable passed to migetpacks that is not a known configuration variable will be automatically injected into the generated Dockerfile as ENV statements. This allows you to pass custom build-time settings without modifying migetpacks.

# Pass NODE_OPTIONS to increase heap size for large builds
docker run --rm \
  -v ./my-app:/workspace/source \
  -v /var/run/docker.sock:/var/run/docker.sock \
  -e OUTPUT_IMAGE=my-app:latest \
  -e NODE_OPTIONS="--max-old-space-size=4096" \
  miget/migetpacks:latest

# Pass multiple custom variables
docker run --rm \
  -v ./my-app:/workspace/source \
  -v /var/run/docker.sock:/var/run/docker.sock \
  -e OUTPUT_IMAGE=my-app:latest \
  -e NODE_OPTIONS="--max-old-space-size=4096" \
  -e VITE_API_URL="https://api.example.com" \
  -e MY_BUILD_FLAG="true" \
  miget/migetpacks:latest

Common use cases:

NODE_OPTIONS="--max-old-space-size=4096" - Increase Node.js heap for large builds
VITE_* / NEXT_PUBLIC_* - Frontend build-time variables
RAILS_MASTER_KEY - Rails credentials key for asset precompilation
Custom feature flags for conditional compilation

Note: Sensitive variables like AWS_* credentials and Docker configuration are automatically filtered out and never injected into the Dockerfile.

LANGUAGE Values

Force a specific language by setting LANGUAGE:

Value	Description
`nodejs`	Node.js (npm, yarn, pnpm)
`deno`	Deno runtime
`bun`	Bun runtime
`python`	Python (pip, uv)
`ruby`	Ruby (bundler)
`go`	Go
`rust`	Rust (cargo)
`php`	PHP (FrankenPHP + Composer)
`java`	Java (Maven or Gradle)
`kotlin`	Kotlin (Gradle)
`scala`	Scala (sbt)
`clojure`	Clojure (Leiningen)
`.net` or `dotnet`	.NET / C#
`elixir`	Elixir (Mix)
`dockerfile`	Use project's Dockerfile directly
`compose`	Build all services from compose.yaml

Procfile Support

Define processes in a Procfile:

web: bundle exec puma -C config/puma.rb
worker: bundle exec sidekiq
release: bundle exec rails db:migrate

Priority order:

RUN_COMMAND environment variable
web: process from Procfile
First process in Procfile
Language-specific default

Multi-Buildpack

Build apps with multiple languages:

# Ruby app with Node.js for asset compilation
docker run --rm \
  -v ./my-rails-app:/workspace/source \
  -v /var/run/docker.sock:/var/run/docker.sock \
  -e OUTPUT_IMAGE=my-rails-app:latest \
  -e BUILDPACKS=ruby,nodejs \
  miget/migetpacks:latest

Docker Hardened Images

Use minimal, CVE-free Docker Hardened Images:

docker run --rm \
  -v ./my-app:/workspace/source \
  -v /var/run/docker.sock:/var/run/docker.sock \
  -e OUTPUT_IMAGE=my-app:latest \
  -e USE_DHI=true \
  miget/migetpacks:latest

DHI images are distroless (no shell, no apt-get) with minimal attack surface.

Docker Desktop (Mac/Windows)

Docker Desktop stores credentials in the system keychain, not in ~/.docker/config.json. Extract credentials and pass them as environment variables:

# Extract credentials from Docker Desktop keychain
DHI_USERNAME=$(echo "dhi.io" | docker-credential-desktop get | jq -r '.Username')
DHI_PASSWORD=$(echo "dhi.io" | docker-credential-desktop get | jq -r '.Secret')

# Build with DHI
docker run --rm \
  -v "$(pwd):/workspace/source:ro" \
  -v /var/run/docker.sock:/var/run/docker.sock \
  -e OUTPUT_IMAGE=my-app:local \
  -e ARCH=arm64 \
  -e USE_DHI=true \
  -e DHI_USERNAME="$DHI_USERNAME" \
  -e DHI_PASSWORD="$DHI_PASSWORD" \
  miget/migetpacks:latest

Dockerfile & Compose Support

Custom Dockerfile

migetpacks prioritizes its optimized builds for known languages. A Dockerfile is only used as a fallback when no supported language is detected. To force your Dockerfile, use LANGUAGE=dockerfile:

# Force Dockerfile mode (recommended when you have both language files and Dockerfile)
docker run --rm \
  -v ./my-app:/workspace/source \
  -v /var/run/docker.sock:/var/run/docker.sock \
  -e OUTPUT_IMAGE=my-app:latest \
  -e LANGUAGE=dockerfile \
  miget/migetpacks:latest

# Fallback behavior (uses Dockerfile only if no language detected)
docker run --rm \
  -v ./my-app:/workspace/source \
  -v /var/run/docker.sock:/var/run/docker.sock \
  -e OUTPUT_IMAGE=my-app:latest \
  miget/migetpacks:latest

# Use custom Dockerfile path
docker run --rm \
  -v ./my-app:/workspace/source \
  -v /var/run/docker.sock:/var/run/docker.sock \
  -e OUTPUT_IMAGE=my-app:latest \
  -e DOCKERFILE_PATH=docker/Dockerfile.prod \
  miget/migetpacks:latest

Docker Compose

Multi-service builds from compose.yaml:

# compose.yaml
services:
  api:
    build: ./api
  web:
    build: ./web

# Auto-detect compose file
docker run --rm \
  -v ./my-project:/workspace/source \
  -v /var/run/docker.sock:/var/run/docker.sock \
  -e OUTPUT_IMAGE=ghcr.io/user/myproject:latest \
  miget/migetpacks:latest
# Builds: ghcr.io/user/myproject-api:latest, ghcr.io/user/myproject-web:latest

# Force compose mode
docker run --rm \
  -v ./my-project:/workspace/source \
  -v /var/run/docker.sock:/var/run/docker.sock \
  -e OUTPUT_IMAGE=ghcr.io/user/myproject:latest \
  -e LANGUAGE=compose \
  miget/migetpacks:latest

Monorepo Support

Build a specific subdirectory:

docker run --rm \
  -v ./monorepo:/workspace/source \
  -v /var/run/docker.sock:/var/run/docker.sock \
  -e PROJECT_PATH=services/api \
  -e OUTPUT_IMAGE=my-api:latest \
  miget/migetpacks:latest

Build Caching

Package Manager Cache

Mount a cache directory for npm, pip, bundler, cargo, etc.:

docker run --rm \
  -v ./my-app:/workspace/source \
  -v /var/run/docker.sock:/var/run/docker.sock \
  -v /path/to/cache:/cache \
  -e OUTPUT_IMAGE=my-app:latest \
  -e BUILD_CACHE_DIR=/cache \
  miget/migetpacks:latest

Registry Cache

Use BuildKit's registry-based caching for Docker layer caching:

docker run --rm \
  -v ./my-app:/workspace/source \
  -v /var/run/docker.sock:/var/run/docker.sock \
  -e OUTPUT_IMAGE=ghcr.io/user/my-app:latest \
  -e CACHE_IMAGE=ghcr.io/user/my-app-cache \
  miget/migetpacks:latest

Private Registry Authentication

When pushing to private registries, migetpacks needs access to your Docker credentials. Since migetpacks runs inside a container, you must mount the Docker config directory.

Docker

# Log in to your registry first
docker login registry.example.com

# Mount the docker config so migetpacks can push
docker run --rm \
  -v ./my-app:/workspace/source \
  -v /var/run/docker.sock:/var/run/docker.sock \
  -v ~/.docker/config.json:/root/.docker/config.json:ro \
  -e OUTPUT_IMAGE=registry.example.com/my-app:latest \
  miget/migetpacks:latest

GitHub Actions

- name: Log in to registry
  uses: docker/login-action@v3
  with:
    registry: registry.example.com
    username: ${{ secrets.REGISTRY_USERNAME }}
    password: ${{ secrets.REGISTRY_PASSWORD }}

- name: Build and push with migetpacks
  run: |
    docker run --rm \
      -v ${{ github.workspace }}:/workspace/source:ro \
      -v /var/run/docker.sock:/var/run/docker.sock \
      -v /home/runner/.docker/config.json:/root/.docker/config.json:ro \
      -e OUTPUT_IMAGE=registry.example.com/my-app:${{ github.sha }} \
      -e CACHE_IMAGE=registry.example.com/my-app:cache \
      miget/migetpacks:latest

Key points:

Mount config.json file only (buildx needs to create state in .docker/buildx/)
Use :ro (read-only) for the config file
On GitHub-hosted runners, the path is /home/runner/.docker/config.json
On self-hosted runners, use $HOME/.docker/config.json

Build Results

Get structured JSON output for CI/CD pipelines:

docker run --rm \
  -v ./my-app:/workspace/source \
  -v /var/run/docker.sock:/var/run/docker.sock \
  -v /tmp/results:/output \
  -e OUTPUT_IMAGE=my-app:latest \
  -e RESULT_FILE=/output/result.json \
  miget/migetpacks:latest

cat /tmp/results/result.json

{
  "status": "success",
  "images": [{"name": "my-app:latest", "ports": ["5000/tcp"]}],
  "processes": {"web": "node server.js"},
  "language": "nodejs",
  "build_time": 45
}

Examples

Working examples for all languages in examples/:

nodejs-example, deno-example, bun-example
python-example, ruby-example, php-hello-world
go-hello-world, rust-example
java-hello-world, kotlin-example, scala-example
dotnet-hello-world, elixir-example
dockerfile-example, compose-example

Development

# Run detection tests
make test-detect

# Build the container locally
make build

# Test a language build
make test-nodejs
make test-python
make test-go

About

migetpacks is built by miget.com - unlimited apps, one price. We use migetpacks to build customer apps with zero configuration.

License

O'Saasy License (Modified for Cloud/PaaS) - see LICENSE for details.

Name		Name	Last commit message	Last commit date
.github/workflows		.github/workflows
bin		bin
docs		docs
etc/docker		etc/docker
examples		examples
lib		lib
shipwright		shipwright
test		test
.dockerignore		.dockerignore
.gitignore		.gitignore
Dockerfile		Dockerfile
Dockerfile.alpine		Dockerfile.alpine
LICENSE		LICENSE
Makefile		Makefile
README.md		README.md

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migetpacks

Features

Requirements

Quick Start

Docker

GitHub Actions (GitHub-hosted runners)

GitHub Actions (Self-hosted runners)

Supported Languages

Environment Variables

Caching Options

Docker Hardened Images

External Private Registry

Custom Build Environment Variables

LANGUAGE Values

Procfile Support

Multi-Buildpack

Docker Hardened Images

Docker Desktop (Mac/Windows)

Dockerfile & Compose Support

Custom Dockerfile

Docker Compose

Monorepo Support

Build Caching

Package Manager Cache

Registry Cache

Private Registry Authentication

Docker

GitHub Actions

Build Results

Examples

Development

About

License

About

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migetpacks

Features

Requirements

Quick Start

Docker

GitHub Actions (GitHub-hosted runners)

GitHub Actions (Self-hosted runners)

Supported Languages

Environment Variables

Caching Options

Docker Hardened Images

External Private Registry

Custom Build Environment Variables

LANGUAGE Values

Procfile Support

Multi-Buildpack

Docker Hardened Images

Docker Desktop (Mac/Windows)

Dockerfile & Compose Support

Custom Dockerfile

Docker Compose

Monorepo Support

Build Caching

Package Manager Cache

Registry Cache

Private Registry Authentication

Docker

GitHub Actions

Build Results

Examples

Development

About

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