# Docker Quick Reference

## 🚀 Quick Start

```bash
# Build and run (one command)
docker build -t argparse-builder . && docker run -d -p 8080:8080 argparse-builder

# Or with docker-compose
docker-compose up -d
```

## 📦 Files Included

```
Dockerfile              ← Production (scratch-based, ~7MB)
Dockerfile.alpine       ← Development (Alpine, ~15MB)
docker-compose.yml      ← Easy deployment
.dockerignore           ← Build optimization
k8s-deployment.yaml     ← Kubernetes manifest
DOCKER_GUIDE.md         ← Complete documentation
Makefile.docker         ← Build automation
main_enhancements.go    ← Health check & config code
```

## 🔨 Build Options

```bash
# Production (minimal)
docker build -t argparse-builder .

# Development (with shell)
docker build -f Dockerfile.alpine -t argparse-builder:alpine .

# Multi-platform
docker buildx build --platform linux/amd64,linux/arm64 -t argparse-builder .
```

## ▶️ Run Options

```bash
# Basic
docker run -d -p 8080:8080 argparse-builder

# With limits
docker run -d -p 8080:8080 --memory=128m --cpus=0.5 argparse-builder

# Secure
docker run -d -p 8080:8080 --read-only --cap-drop=ALL argparse-builder
```

## 🎯 Image Sizes

| Image   | Size    | Use          |
| ------- | ------- | ------------ |
| scratch | ~7 MB   | Production   |
| alpine  | ~15 MB  | Development  |
| no-opt  | ~900 MB | ❌ Don't use |

## 🔍 Health Check

```bash
# Check health
curl http://localhost:8080/health

# Docker health status
docker ps --filter "health=healthy"
```

## 📊 Monitoring

```bash
# Logs
docker logs -f argparse-builder

# Stats
docker stats argparse-builder

# Inspect
docker inspect argparse-builder
```

## 🎪 Kubernetes

```bash
# Deploy
kubectl apply -f k8s-deployment.yaml

# Check status
kubectl get pods -n argparse-builder
kubectl get svc -n argparse-builder

# Logs
kubectl logs -f deployment/argparse-builder -n argparse-builder
```

## 🛠️ Makefile Commands

```bash
make docker-build      # Build image
make docker-run        # Run container
make docker-logs       # View logs
make compose-up        # Start with compose
make clean             # Clean everything
```

## 🔒 Security Features

- Non-root user (UID 65534)
- Read-only filesystem
- No capabilities
- Static binary
- Minimal attack surface

## 📝 Key Points

✅ Dockerfile uses multi-stage build (builder + scratch)
✅ Healthcheck endpoint at /health
✅ Environment vars: PORT, LOG_LEVEL
✅ Graceful shutdown support
✅ Resource limits configured
✅ Security hardened by default

## 🌐 Registry Push

```bash
# GitHub Container Registry
docker tag argparse-builder ghcr.io/username/argparse-builder
docker push ghcr.io/username/argparse-builder

# Docker Hub
docker tag argparse-builder username/argparse-builder
docker push username/argparse-builder
```

## 🔄 CI/CD Ready

GitHub Actions example included in DOCKER_GUIDE.md for:

- Automated builds on push
- Multi-platform support
- Registry push
- Cache optimization

See DOCKER_GUIDE.md for complete instructions.

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