Backing Up Docker Volumes

To automate docker partition backups, I recommend using Docker-volume-backup image (https://github.com/offen/docker-volume-backup). This lightweight image (about 15 MB) allows you to connect to any volume in docker and backup files to a local directory, S3-compatible storage (AWS S3, MimIO, Ceph, etc.), or send save it to a remote device via WebDAV or SSH.

If you need to quickly run a one-time volume backup, you can use:

docker run --rm \
 -v data:/backup/data \
 --env AWS_ACCESS_KEY_ID="<xxx>" \
 --env AWS_SECRET_ACCESS_KEY="<xxx>" \
 --env AWS_S3_BUCKET_NAME="<xxx>" \
 --entrypoint backup \
 offen/docker-volume-backup:v2

If you need to backup via SSH:

docker run --rm \
 -v data:/backup/data \
 --env SSH_HOST_NAME="backupsrv1.local" \
 --env SSH_PORT=2222 \
 --env SSH_REMOTE_PATH="/mnt/backup/" \
 --env SSH_USER="user"
 --env SSH_PASSWORD="password"
 --entrypoint backup \
 offen/docker-volume-backup:v2

You can build a backup image using docker-compose:

version: '3'
services:
  backup:
    image: offen/docker-volume-backup:latest
    environment:
      BACKUP_CRON_EXPRESSION: "0 * * * *"
      BACKUP_PRUNING_PREFIX: backup-
      BACKUP_RETENTION_DAYS: 7
      AWS_BUCKET_NAME: backup-bucket
      AWS_ACCESS_KEY_ID: <xxx>
      AWS_SECRET_ACCESS_KEY: <xxx>
    volumes:
      - data:/backup/my-app-backup:ro
      - /var/run/docker.sock:/var/run/docker.sock:ro
volumes:
  data:

Before the backup, you can execute arbitrary commands inside the target docker container. For example, to make a database dump (for example, if you are backing up Zabbix Server) or something else.