docker-s3-volume

Creates a Docker container that is restored and backed up to a directory on s3. You could use this to run short lived processes that work with and persist data to and from S3.

Usage

For the simplest usage, you can just start the data container:

docker run -d --name my-data-container \
           elementar/s3-volume /data s3://mybucket/someprefix

This will download the data from the S3 location you specify into the container's /data directory. When the container shuts down, the data will be synced back to S3.

To use the data from another container, you can use the --volumes-from option:

docker run -it --rm --volumes-from=my-data-container busybox ls -l /data

Configuring a sync interval

When the BACKUP_INTERVAL environment variable is set, a watcher process will sync the /data directory to S3 on the interval you specify. The interval can be specified in seconds, minutes, hours or days (adding s, m, h or d as the suffix):

docker run -d --name my-data-container -e BACKUP_INTERVAL=2m \
           elementar/s3-volume /data s3://mybucket/someprefix

Configuring credentials

If you are running on EC2, IAM role credentials should just work. Otherwise, you can supply credential information using environment variables:

docker run -d --name my-data-container \
           -e AWS_ACCESS_KEY_ID=... -e AWS_SECRET_ACCESS_KEY=... \
           elementar/s3-volume /data s3://mybucket/someprefix

Any environment variable available to the aws-cli command can be used. see http://docs.aws.amazon.com/cli/latest/userguide/cli-environment.html for more information.

Configuring an endpoint URL

If you are using an S3-compatible service (such as Oracle OCI Object Storage), you may want to set the service's endpoint URL:

docker run -d --name my-data-container -e ENDPOINT_URL=... \
           elementar/s3-volume /data s3://mybucket/someprefix

Forcing a sync

A final sync will always be performed on container shutdown. A sync can be forced by sending the container the USR1 signal:

docker kill --signal=USR1 my-data-container

Forcing a restoration

The first time the container is ran, it will fetch the contents of the S3 location to initialize the /data directory. If you want to force an initial sync again, you can run the container again with the --force-restore option:

docker run -d --name my-data-container \
           elementar/s3-volume --force-restore /data s3://mybucket/someprefix

Deletion and sync

By default if there are files that are deleted in your local file system, those will be deleted remotely. If you wish to turn this off, set the environment variable S3_SYNC_FLAGS to an empty string:

docker run -d -e S3_SYNC_FLAGS="" elementar/s3-volume /data s3://mybucket/someprefix

Using Compose and named volumes

Most of the time, you will use this image to sync data for another container. You can use docker-compose for that:

# docker-compose.yaml
version: "2"

volumes:
  s3data:
    driver: local

services:
  s3vol:
    image: elementar/s3-volume
    command: /data s3://mybucket/someprefix
    volumes:
      - s3data:/data
  db:
    image: postgres
    volumes:
      - s3data:/var/lib/postgresql/data

Contributing

1. Fork it!
2. Create your feature branch: git checkout -b my-new-feature
3. Commit your changes: git commit -am 'Add some feature'
4. Push to the branch: git push origin my-new-feature
5. Submit a pull request :D

Credits

• Original Developer - Dave Newman (@whatupdave)
• Current Maintainer - Fábio Batista (@fabiob)

License

This repository is released under the MIT license:

• www.opensource.org/licenses/MIT