Sub-containers: path resolution

Hi,

I’m using docker for a CI (building whole debian repositories) where jenkins is in one container, while the actual build tool is spawning up its own containers (creates/maintains the images itself) and needs to share directories with it’s containers.

When fired up from the host, this tool works really fine (using bind mounts), but from within a container it doesn’t work, as dockerd misinterprets the src directory as within the host instead of the container.

This is a scneario where it would be very helpful if dockerd could act on behalf of the container (use it’s fs ns instead the hosts one). The container could be identified via unix socket (retrieve the calling UID and check which pid ns it belongs to).

–mtx