[CRIU] runc container migration

[Adrian Reber]

Migrating a runc container works pretty good with the following steps:

 * runc checkpoint <container>
 * rsync checkpoint
 * rsync filesystem
 * runc restore <container> # on the destination host

If I am using a read-only filesystem in my runc config.json file I need
to mount /tmp as tmpfs. I am also adding other filesystems as tmpfs
(like /run) and I am currently not sure how to correctly migrate the
content of those tmpfs's.

Somehow I need to enter the container after all processes have been
dumped by criu and while the content of all tmpfs's is still available.

Is there some way to do this correctly? It sounds like it would be
runc's job to offer an interface to export the tmpfs filesystems.
Curious if anybody knows a way to do get the content of the tmpfs's?

		Adrian