docker-volume-backup/README.md

docker-volume-backup

Docker image for performing simple backups of Docker volumes. Main features:

• Mount volumes into the container, and they'll get backed up
• Use full cron expressions for scheduling the backups
• Backs up to local disk, AWS S3, or both
• Optionally stops other containers for the duration of the backup, and starts them again afterward, to ensure consistent backups of things like database files, etc

Examples

Backing up locally

Say you're running some dashboards with Grafana and want to back them up:

version: "3"

services:
  dashboard:
    image: grafana/grafana:5.3.4
    volumes:
      - grafana-data:/var/lib/grafana           # This is where Grafana keeps its data

  backup:
    image: futurice/docker-volume-backup:1.1.0
    environment:
      BACKUP_SOURCES: /mnt/grafana              # Where to read data from
      BACKUP_ARCHIVE: /mnt/backups              # Where to write backups to
    volumes:
      - grafana-data:/mnt/grafana:ro            # Mount the Grafana data volume (read-only)
      - ./backups:/mnt/backups                  # Mount a local folder as the backup archive

volumes:
  grafana-data:

This will back up the Grafana data volume, once per day, and write it to ./backups with a filename like backup-2018-11-26.tar.gz.

Backing up to S3

Off-site backups are better, though:

version: "3"

services:
  dashboard:
    image: grafana/grafana:5.3.4
    volumes:
      - grafana-data:/var/lib/grafana           # This is where Grafana keeps its data

  backup:
    image: futurice/docker-volume-backup:1.1.0
    environment:
      BACKUP_SOURCES: /mnt/grafana              # Where to read data from
      AWS_S3_BUCKET_NAME: my-backup-bucket      # S3 bucket which you own, and already exists
      AWS_ACCESS_KEY_ID: ${AWS_ACCESS_KEY_ID}   # Read AWS secrets from environment (or a .env file)
      AWS_SECRET_ACCESS_KEY: ${AWS_SECRET_ACCESS_KEY}
    volumes:
      - grafana-data:/mnt/grafana:ro            # Mount the Grafana data volume (read-only)

volumes:
  grafana-data:

This configuration will back up to AWS S3 instead.

Stopping containers while backing up

It's not generally safe to read files to which other processes might be writing. You may end up with corrupted copies. You generally don't want corrupted backups.

You can give the backup container access to the Docker socket, and label any containers that need to be stopped while the backup runs:

version: "3"

services:
  dashboard:
    image: grafana/grafana:5.3.4
    volumes:
      - grafana-data:/var/lib/grafana           # This is where Grafana keeps its data
    labels:
      - "docker-volume-backup.stop-during-backup=true"

  backup:
    image: futurice/docker-volume-backup:1.1.0
    environment:
      BACKUP_SOURCES: /mnt/grafana              # Where to read data from
      AWS_S3_BUCKET_NAME: my-backup-bucket      # S3 bucket which you own, and already exists
      AWS_ACCESS_KEY_ID: ${AWS_ACCESS_KEY_ID}   # Read AWS secrets from environment (or a .env file)
      AWS_SECRET_ACCESS_KEY: ${AWS_SECRET_ACCESS_KEY}
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock:ro # Allow use of the "stop-during-backup" label
      - grafana-data:/mnt/grafana:ro            # Mount the Grafana data volume (read-only)

volumes:
  grafana-data:

This configuration allows you to safely back up things like databases, if you can tolerate a bit of downtime.