How to deal with persistent storage (e.g. database

Question

How do people deal with persistent storage for your Docker containers?

I am currently using this approach: build the image, e.g. for PostgreSQL, and then start the container with

docker run --volumes-from c0dbc34fd631 -d app_name/postgres

IMHO, that has the drawback, that I must not ever (by accident) delete container "c0dbc34fd631".

Another idea would be to mount host volumes "-v" into the container, however, the userid within the container does not necessarily match the userid from the host, and then permissions might be messed up.

Note: Instead of --volumes-from 'cryptic_id' you can also use --volumes-from my-data-container where my-data-container is a name you assigned to a data-only container, e.g. docker run --name my-data-container ... (see the accepted answer)

Answer 1

There are several levels of managing persistent data, depending on your needs:

• Store it on your host
  • Use the flag -v host-path:container-path to persist container directory data to a host directory.
  • Backups/restores happen by running a backup/restore container (such as tutumcloud/dockup) mounted to the same directory.
• Create a data container and mount its volumes to your application container
  • Create a container that exports a data volume, use --volumes-from to mount that data into your application container.
  • Backup/restore the same as the above solution.
• Use a Docker volume plugin that backs an external/third-party service
  • Docker volume plugins allow your datasource to come from anywhere - NFS, AWS (S3, EFS, and EBS)
  • Depending on the plugin/service, you can attach single or multiple containers to a single volume.
  • Depending on the service, backups/restores may be automated for you.
  • While this can be cumbersome to do manually, some orchestration solutions - such as Rancher - have it baked in and simple to use.
  • Convoy is the easiest solution for doing this manually.

Answer 2

I'm just using a predefined directory on the host to persist data for PostgreSQL. Also, this way it is possible to easily migrate existing PostgreSQL installations to Docker containers: https://crondev.com/persistent-postgresql-inside-docker/