Add support for configuring the upper directory of a docker container under a given directory

[tchaton]

Description

When sending a docker spec to the deamon to create a new container, I would like to be able to specifiy how the deamon GraphDriver should place the upper dir of the container overlay.

This would enable me to isolate the upper dir of the user container on a different partition.

I managed to write a bash script to do this, but I can't exclusively place a container on a different partition as the /var/lib/docker/image/overlay2/imagedb/content/sha256/ and /var/lib/docker/containers/ are empty when I am doing the bind mounting.

I would really like to avoid to have to write my own GraphDriver Plugin: https://docs.docker.com/engine/extend/plugins_graphdriver/

I would really appreciate some help.

[tchaton]

Any updates ? This is quite important for us. I have a solution to make it work, but it is racy.

I can also work on contributing this.

[tchaton]

Hey @thaJeztah @GordonTheTurtle Any updates ?

[vvoland]

There are no plans to support that.
Also, graphdriver plugins are deprecated now. You can use the containerd image store integration and write a custom snapshotter to achieve that.

[tchaton]

Thanks @vvoland . Do you have docs to create a custom snapshotter ?