low-code-react-app-b/scripts/QEMU_SCRIPTS_README.md

Multi-Architecture Build Scripts

This directory contains helper scripts for QEMU multi-architecture Docker builds.

Scripts

🚀 build-multiarch.sh

Builds multi-architecture Docker images locally using QEMU and Docker Buildx.

Usage:

# Make executable
chmod +x scripts/build-multiarch.sh

# Build for local testing (loads into Docker)
./scripts/build-multiarch.sh myapp latest

# Build and push to registry
./scripts/build-multiarch.sh myapp latest "linux/amd64,linux/arm64" ghcr.io --push

# Custom platforms
./scripts/build-multiarch.sh myapp v1.0 "linux/amd64,linux/arm64,linux/arm/v7" ghcr.io --push

Parameters:

1. IMAGE_NAME - Docker image name (default: myapp)
2. IMAGE_TAG - Image tag (default: latest)
3. PLATFORMS - Comma-separated platforms (default: linux/amd64,linux/arm64)
4. REGISTRY - Container registry (default: ghcr.io)
5. --push - Push to registry (omit to load locally)

Features:

• ✅ Automatic QEMU setup
• ✅ Buildx builder configuration
• ✅ Color-coded output
• ✅ Error handling
• ✅ Progress indicators

🔍 validate-qemu.sh

Validates QEMU installation and multi-architecture build capabilities.

Usage:

# Make executable
chmod +x scripts/validate-qemu.sh

# Run validation
./scripts/validate-qemu.sh

Checks:

• ✅ Docker installation
• ✅ Docker Buildx availability
• ✅ QEMU installation
• ✅ QEMU binaries functionality
• ✅ Buildx builder setup
• ✅ Platform support (AMD64, ARM64)
• ✅ Test builds for each platform
• ✅ CI/CD configuration validation

Exit Codes:

• 0 - All validations passed
• 1 - One or more validations failed

Quick Start

First Time Setup

# 1. Make scripts executable
chmod +x scripts/*.sh

# 2. Validate your environment
./scripts/validate-qemu.sh

# 3. Build your first multi-arch image
./scripts/build-multiarch.sh codeforge latest

Local Development

# Build and load into local Docker (AMD64 only for speed)
./scripts/build-multiarch.sh myapp dev

# Run the image
docker run -p 80:80 ghcr.io/myapp:dev

Production Release

# Build multi-arch and push to registry
./scripts/build-multiarch.sh codeforge v1.2.3 "linux/amd64,linux/arm64" ghcr.io --push

# Verify the manifest
docker manifest inspect ghcr.io/codeforge:v1.2.3

Supported Platforms

Default Platforms

• linux/amd64 - Intel/AMD 64-bit (x86_64)
• linux/arm64 - ARM 64-bit (aarch64)

Additional Platforms (Optional)

• linux/arm/v7 - ARM 32-bit (armv7l) - Raspberry Pi 3 and older
• linux/arm/v6 - ARM 32-bit (armv6l) - Raspberry Pi Zero
• linux/ppc64le - IBM POWER (Little Endian)
• linux/s390x - IBM Z mainframe
• linux/386 - Intel/AMD 32-bit (i386)

CI/CD Integration

These scripts are reference implementations. The actual CI/CD pipelines use:

GitHub Actions

- name: Set up QEMU
  uses: docker/setup-qemu-action@v3
  with:
    platforms: linux/amd64,linux/arm64

CircleCI

- run:
    name: Install QEMU
    command: docker run --rm --privileged multiarch/qemu-user-static --reset -p yes

GitLab CI

before_script:
  - docker run --rm --privileged multiarch/qemu-user-static --reset -p yes
  - docker buildx create --name multiarch --driver docker-container --use

Jenkins

sh 'docker run --rm --privileged multiarch/qemu-user-static --reset -p yes'
sh 'docker buildx create --name multiarch --driver docker-container --use'

Troubleshooting

Permission Denied

# Run with sudo
sudo ./scripts/build-multiarch.sh myapp latest

# Or add your user to docker group
sudo usermod -aG docker $USER
newgrp docker

QEMU Not Found

# Manually install QEMU
docker run --rm --privileged multiarch/qemu-user-static --reset -p yes

Buildx Not Available

# Install Docker Buildx
docker buildx install

# Verify installation
docker buildx version

Slow Builds

Cross-compilation (especially AMD64 → ARM64) is slower than native builds. This is normal.

Optimization tips:

• Use build cache: --cache-from type=gha --cache-to type=gha,mode=max
• Build single platform for development: remove --platform or specify one arch
• Use native runners: GitHub Actions has ARM64 runners available

Platform Not Supported

Some base images don't support all platforms. Check the base image documentation.

# Check available platforms for an image
docker manifest inspect alpine:latest

Performance Benchmarks

Approximate build times for a typical web application:

Configuration	Time	Notes
AMD64 only (native)	5-8 min	Fastest
ARM64 only (emulated)	10-15 min	Cross-compiled on AMD64
AMD64 + ARM64	15-20 min	Both platforms
AMD64 + ARM64 + ARMv7	20-30 min	Three platforms

Environment Variables

Scripts support these environment variables:

# Docker registry credentials
export DOCKER_USERNAME="your-username"
export DOCKER_PASSWORD="your-token"

# Custom registry
export REGISTRY="ghcr.io"

# Build options
export DOCKER_BUILDKIT=1
export BUILDKIT_PROGRESS=plain

Examples

Example 1: Development Build

# Quick local build for testing
./scripts/build-multiarch.sh myapp dev

# Test the image
docker run -p 3000:80 ghcr.io/myapp:dev
curl http://localhost:3000

Example 2: Staging Release

# Build and push to staging
./scripts/build-multiarch.sh myapp staging "linux/amd64,linux/arm64" ghcr.io --push

# Deploy on staging server
docker pull ghcr.io/myapp:staging
docker run -d -p 80:80 ghcr.io/myapp:staging

Example 3: Production Release

# Build with version tag
./scripts/build-multiarch.sh myapp v2.1.0 "linux/amd64,linux/arm64" ghcr.io --push

# Also tag as latest
docker tag ghcr.io/myapp:v2.1.0 ghcr.io/myapp:latest
docker push ghcr.io/myapp:latest

Example 4: IoT/Edge Devices

# Build for Raspberry Pi (ARMv7 + ARM64)
./scripts/build-multiarch.sh iot-app v1.0 "linux/arm64,linux/arm/v7" ghcr.io --push

# Pull on Raspberry Pi
docker pull ghcr.io/iot-app:v1.0
docker run ghcr.io/iot-app:v1.0

Additional Resources

• QEMU Integration Guide - Full documentation
• CI/CD Summary - Implementation details
• Docker Buildx - Official documentation
• QEMU User Static - QEMU binaries

Contributing

When adding new scripts:

1. Follow the existing script structure
2. Add color-coded output for better UX
3. Include error handling with meaningful messages
4. Document usage and parameters
5. Update this README

Support

For issues with multi-architecture builds:

1. Run validation: ./scripts/validate-qemu.sh
2. Check Docker version: docker --version (v20.10+ recommended)
3. Verify QEMU: docker run --rm multiarch/qemu-user-static --version
4. Review logs for specific error messages

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Last Updated: 2024 Maintained by: Development Team