Add container volume cp

[PhantomInTheWire]

Type of Change

• Bug fix
• New feature
• Breaking change
• Documentation update

Motivation and Context

related issue: #895

Testing

• Tested locally
• Added/updated tests
• Added/updated docs

[jglogan]

Hi @PhantomInTheWire, sorry that it took a while to get to this one.

See the comment here regarding container cp. The same problem applies to a command like container volume cp.

What you have right now isn't copying into the volume. A volume is a sparse disk image file with an ext4 filesystem written inside it. From what I can tell, your code is copying files around the host (it doesn't build for me as the Archive type isn't found).

To copy in and out of a volume we'd need for the volume to not be used in a running container, and then we'd need to launch a utility container that mounts the volume, and then copy from host to the utility container using the equivalent of container cp.

What could be possible is to add a --from to the container volume create command that allows the user to initialize a new named volume using data on their host.