# docker-volume-s3-backup

## Introduction

This project provides a Docker image that periodically backs up a Docker volume to AWS S3 as a gzipped tape archive, and can restore a backup as needed.

## Usage

### Backup

Example `docker-compose.yml`:

```yaml
services:
  my_service:
    image: ...
    volumes:
      data:/app/some-data-dir

  volume_backup:
    image: garraflavatra/docker-volume-s3-backup
    volumes:
      data:/data/folder1
    environment:
      BACKUP_NAME: myvolume         # required
      SCHEDULE: '@weekly'           # optional
      BACKUP_KEEP_DAYS: 7           # optional
      PASSPHRASE: passphrase        # optional
      S3_REGION: region             # or set S3_ENDPOINT if you do not use AWS
      S3_ACCESS_KEY_ID: key         # alias S3_ACCESS_KEY
      S3_SECRET_ACCESS_KEY: secret  # alias S3_SECRET_KEY
      S3_BUCKET: my-bucket          # required
      S3_PREFIX: backup             # required
```

- You can mount as many folders into `/data` as you like. Everything in `/data` is copied to your S3 storage in a single `.tar.gz`.
- The `SCHEDULE` variable determines backup frequency. See go-cron schedules documentation [here](http://godoc.org/github.com/robfig/cron#hdr-Predefined_schedules). Omit to run the backup immediately and then exit.
- If `PASSPHRASE` is provided, the backup will be encrypted using GPG.
- Run `docker exec <container_name> sh backup.sh` to trigger a backup ad-hoc.
- If `BACKUP_KEEP_DAYS` is set, backups older than this many days will be deleted from S3.
- Set `S3_ENDPOINT` if you're using a non-AWS S3-compatible storage provider.

### Restore

> [!CAUTION]
> All existing files will be replaced by the backup content!

#### From latest backup

```sh
docker exec <container_name> sh restore.sh
```

> [!NOTE]
> If your bucket has over 1000 files, the latest may not be restored – the S3 `ls` command is issued only once.

#### From specific backup

```sh
docker exec <container_name> sh restore.sh <timestamp>
```

## Development

You can use the Docker Compose file in the root with your own S3 bucket for development and testing.

```sh
cp .env.example .env
# fill out your secrets/params in .env
docker compose up -d
```

## Acknowledgements

This project is a modification of the excellent [`eeshugerman/postgres-backup-s3`](https://github.com/eeshugerman/postgres-backup-s3), which in turn is a fork and re-structuring of [`schickling/postgres-backup-s3`](https://github.com/schickling/dockerfiles/tree/master/postgres-backup-s3) and [`schickling/postgres-restore-s3`](https://github.com/schickling/dockerfiles/tree/master/postgres-restore-s3).

## Copyright

Copyright (c) 2017 Johannes Schickling

Copyright (c) 2022 Elliott Shugerman

Copyright (c) 2025 [Romein van Buren](mailto:romein@smartyellow.nl)

Licensed under the MIT license.