Docker Backup

A Docker container for automated backups of application files and MySQL/MariaDB databases. This solution provides both backup and restore functionality with configurable scheduling.

Installation

You can pull the image directly from Docker Hub:

docker pull mikenowak/backup

Features

• Flexible backup modes:
  • Application files only
  • MySQL/MariaDB database only
  • Both files and database
• Configurable backup schedule
• Automatic cleanup of old backups
• Secure credential handling
• Backup restoration capability

Usage

The container can operate in three modes depending on which environment variables you provide:

1. Application Files Only

For backing up just application files:

version: '3.8'
services:
  backup:
    image: mikenowak/backup
    environment:
      - BACKUP_TIME=0 3 * * *  # Run at 3 AM daily
      - APP_DIRECTORY=/app
      - CLEANUP_OLDER_THAN=30  # Optional
    volumes:
      - ./app:/app:ro
      - ./backups:/backup

2. MySQL/MariaDB Database Only

For backing up just a database:

version: '3.8'
services:
  backup:
    image: mikenowak/backup
    environment:
      - BACKUP_TIME=0 3 * * *
      - MYSQL_HOST=db
      - MYSQL_USER=dbuser
      - MYSQL_DATABASE=myapp
      - MYSQL_PASSWORD_FILE=/run/secrets/db_password
      - CLEANUP_OLDER_THAN=30  # Optional
    volumes:
      - ./backups:/backup
      - ./db_password:/run/secrets/db_password:ro

3. Both Files and Database

For backing up both:

version: '3.8'
services:
  backup:
    image: mikenowak/backup
    environment:
      - BACKUP_TIME=0 3 * * *
      - APP_DIRECTORY=/app
      - MYSQL_HOST=db
      - MYSQL_USER=dbuser
      - MYSQL_DATABASE=myapp
      - MYSQL_PASSWORD_FILE=/run/secrets/db_password
      - CLEANUP_OLDER_THAN=30  # Optional
    volumes:
      - ./app:/app:ro
      - ./backups:/backup
      - ./db_password:/run/secrets/db_password:ro

Environment Variables

Required (at least one set):

• Application backup:
  • APP_DIRECTORY: Directory to backup
• Database backup:
  • MYSQL_HOST: Database host
  • MYSQL_USER: Database user
  • MYSQL_DATABASE: Database name
  • MYSQL_PASSWORD_FILE: Path to file containing database password

Optional:

• BACKUP_TIME: Cron schedule for backups (default: "0 3 * * *")
• CLEANUP_OLDER_THAN: Days to keep backups

Backup Format

Backups are stored in the /backup volume with the following naming convention:

• Application files: app_YYYYMMDD_HHMMSS.tar.gz
• Database dumps: db_YYYYMMDD_HHMMSS.sql.bz2

Performing a Restore

The container includes a restore script to recover from backups. To restore:

1. First, list available backups:

docker exec backup ls -l /backup

1. Restore from a specific backup using the timestamp:

docker exec backup restore YYYYMMDD_HHMMSS

For example:

docker exec backup restore 20240318_030000

Manual Backup

To trigger a manual backup:

docker exec backup backup

Security Considerations

• Database passwords should be provided via a file mount, not environment variables
• Use read-only mounts for source directories where possible
• The backup volume should be properly secured
• Backups are compressed to save space
• Consider encrypting sensitive backups

Logging

• All operations log to stderr/stdout for container logging
• Errors are clearly marked with "ERROR:" prefix
• Informational messages are marked with "INFO:" prefix
• Use docker logs to view the backup history

Building

docker build -t backup .

Development

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

Credits

Inspired by aveltens/wordpress-backup

License

MIT