CRIU iterative (pre-dump) Support in Docker

[GoldenBug]

Hello, I've been doing quite a bit of research into using CRIU in conjunction with Docker to perform live migration of Docker containers.

My main question is: Does docker start --checkpoint support iterative pre/post dumps created with runc/CRIU?

From looking around it looks like:

• This is currently possible with runc itself
• This is currently possible with podman
• Obviously possibly with CRIU directly.

However from what I can, see both from personal testing and the docs, it looks like Docker itself doesn't support restoring multiple checkpoints. Even if you create the checkpoints using runc, Docker is unable to follow the linked checkpoints when rebuilding it, and it just fails.

Is this correct?
I can't find any official sources that absolutely confirm this is the case.

[rst0git]

it looks like Docker itself doesn't support restoring multiple checkpoints

@GoldenBug Yes, this is correct. Docker currently doesn't implement support for iterative checkpointing.

I can't find any official sources that absolutely confirm this is the case.

You can have a look at the source code:
https://github.com/moby/moby/blob/master/client/checkpoint_create.go