Traefik Log Rotation and Monitoring

A lightweight, Alpine-based Docker container that provides automated log rotation and real-time monitoring for Traefik access logs. Features configurable retention policies, colored log output, DNS resolution, and robust error handling.

• Automated Log Rotation: Configurable size and time-based rotation
• Real-time Monitoring: Live log tailing with colored output
• DNS Resolution: Automatically resolves client IPs to hostnames
• Status Code Filtering: Configurable HTTP status code filtering
• Resource Efficient: <64MB memory footprint
• Signal Handling: Graceful shutdown on container stop
• Health Checks: Built-in container health monitoring
• Comprehensive Logging: Structured logging with multiple levels
• Zero Dependencies: Self-contained with all required tools

1. Download the example compose file:

   curl -o docker-compose.yml https://raw.githubusercontent.com/bodencrouch/logrotate-traefik/main/examples/docker-compose.simple.yml

2. Start the service:

   docker-compose up -d logrotate-traefik

3. View real-time logs:

   docker-compose logs -f logrotate-traefik

docker run -d \
  --name logrotate-traefik \
  --restart unless-stopped \
  -v /path/to/traefik/logs:/var/log/traefik:rw \
  -e TZ=America/Chicago \
  -e LOG_LEVEL=info \
  your-registry/logrotate-traefik:latest

• 100-999 - All status codes (default)
• 200,201,204 - Specific success codes only
• 400-499 - Client errors only
• 500-599 - Server errors only
• 200,300-399,404 - Mixed ranges and specific codes

logrotate-traefik/
├── Dockerfile              # Multi-stage Docker build
├── Makefile                # Development and build tasks
├── README.md               # This file
├── scripts/
│   ├── entrypoint.sh       # Container initialization
│   └── traefik-logrotate.sh # Main log rotation script
├── config/
│   ├── logrotate.conf      # Example logrotate config
│   └── environment.env.example # Environment variables reference
└── examples/
    ├── docker-compose.yml      # Full example with Traefik
    └── docker-compose.simple.yml # Simple service only

version: '3.8'

services:
  traefik:
    image: traefik:v3.0
    # ... your existing Traefik configuration
    volumes:
      - traefik-logs:/var/log/traefik
    command:
      - --log.filePath=/var/log/traefik/traefik.log
      - --log.format=json

  logrotate-traefik:
    image: your-registry/logrotate-traefik:latest
    container_name: logrotate-traefik
    restart: unless-stopped
    volumes:
      - traefik-logs:/var/log/traefik:rw
    environment:
      TZ: America/Chicago
      LOG_LEVEL: info
    depends_on:
      - traefik

volumes:
  traefik-logs:
    driver: local

deploy:
  resources:
    limits:
      cpus: '0.1'
      memory: 64M
    reservations:
      memory: 8M

The service provides real-time colored log monitoring:

==================================================================
TIMESTAMP           | STA | CLIENT             | HOST                      | METHOD+PATH           | DURATION | SERVICE
==================================================================
2024-01-15T10:30:45Z | 200 | example.com:54321  | api.mysite.com           | GET /api/users        | 45 ms    | api-service
2024-01-15T10:30:46Z | 404 | 192.168.1.100:6789| mysite.com               | GET /missing          | 12 ms    | web-service
2024-01-15T10:30:47Z | 500 | client.example.org | api.mysite.com           | POST /api/data        | 1205 ms  | api-service

• Green: 2xx success responses
• Blue: 3xx redirects
• Yellow: 4xx client errors
• Red: 5xx server errors
• Dynamic: Other codes get unique colors

• Docker
• Docker Compose
• Make (optional, for convenience)

1. Clone the repository:

   git clone https://github.com/bodencrouch/logrotate-traefik.git
   cd logrotate-traefik

2. Set up development environment:

   make dev-setup

3. Build and test locally:

   make build
   make test

4. Run with test logs:

   make run

• Non-root execution: Runs as dedicated logrotate user (UID 1001)
• Minimal attack surface: Alpine-based with minimal packages
• Read-only filesystem: Only log directory requires write access
• Signal handling: Proper cleanup on container termination
• Health checks: Built-in container health monitoring

# Scan for vulnerabilities
make security-scan

# Check image size and layers
make size

• Memory: ~8-64MB (depending on log volume)
• CPU: <0.1 core (burst during rotation)
• Disk I/O: Minimal (rotation and compression only)
• Network: Minimal (DNS lookups only)

• Adjust LOGROTATE_LOOP_SLEEP based on log volume
• Use STATUS_CODES filtering to reduce output
• Set LOGROTATE_MAXSIZE appropriate to your log volume
• Monitor LOGROTATE_MAXDIR_MB to prevent disk usage spikes

1. Container exits immediately

   # Check if log directory is mounted and accessible
   docker logs logrotate-traefik

2. No logs appearing

   # Verify Traefik is writing JSON logs to the mounted volume
   ls -la /path/to/traefik/logs/

3. Permission denied errors

   # Ensure log directory has correct permissions
   chmod 755 /path/to/traefik/logs/
   chmod 644 /path/to/traefik/logs/*.log

4. High memory usage

   # Reduce log retention or increase rotation frequency
   docker exec logrotate-traefik env | grep LOGROTATE

Enable debug logging for troubleshooting:

docker run -e LOG_LEVEL=debug your-registry/logrotate-traefik:latest

# Check rotation status
docker exec logrotate-traefik cat /var/lib/logrotate.status

# Check directory size
docker exec logrotate-traefik du -sh /var/log/traefik

# List rotated files
docker exec logrotate-traefik ls -lah /var/log/traefik/

1. Fork the repository
2. Create a feature branch (git checkout -b feature/amazing-feature)
3. Make your changes
4. Run tests (make test lint)
5. Commit your changes (git commit -m 'Add amazing feature')
6. Push to the branch (git push origin feature/amazing-feature)
7. Open a Pull Request

• Follow shell script best practices
• Add tests for new features
• Update documentation
• Maintain backward compatibility
• Keep Docker image size minimal

This project is licensed under the MIT License - see the LICENSE file for details.

• Issues: GitHub Issues
• Discussions: GitHub Discussions
• Documentation: Wiki

• Traefik - The amazing reverse proxy
• Alpine Linux - Lightweight container base
• logrotate - Log rotation utility

Made with ❤️ for the Traefik community