local backup with another user as root?

[wired2051]

Hi!

I'm new to Docker, so this may be a stupid question, but I dare to ask it anyway: is it possible to make backups with a different user as root?

[helmuthb]

Sorry for the late response.

The question is, of course, not stupid at all :-)

There are three users which are relevant in this context:

• Local user (where you start the container)
• User within the container
• User on the remote system (if using remote backup)

If - on your local system where you want to start the container - your user is a member of the group "docker", then you can start the container without being root. If not, then you would need to have root privileges.

The user within the docker container is root. It's a good idea to allow potential customization of this and allowing to use a container user other than root. By default it's root, because otherwise file ownership would be lost in the backups (all backups would then belong to the user in the docker container).

If you use rsnapshot to back up a remote system, then the remote user could be any user. Of course, you would only be able to back up files which this user can actually read.