Difference between the checkpoint command in runc and youki

[nayuta723]

Part of Implement container restore functionality

There are differences between the checkpoint command in runc and youki.

Please refer to the following:
https://github.com/opencontainers/runc/blob/main/man/runc-checkpoint.8.md

The checkpoint command in youki currently does not support several options that are available in runc, such as --tcp-skip-in-flight and --pre-dump.

[donkomura]

I'm interested in implementing checkpoints. Would it be possible for me to collaborate?

[nayuta723]

Thank you! However, since the Restore function is still under implementation, we're currently unable to perform the verification. Please give me some time to figure out the best way to handle the splitting units.

[nayuta723]

I would like to share two ways you can contribute:

One is to help add components that are currently listed as TODOs for the checkpoint feature in youki.

• I am currently working on a minimal implementation of checkpoint/restore, which you can use as a reference: [WIP] Add basic restore implementation #3429

The other is to contribute by extending criu-rust to enable more options to be used from within youki.

• https://github.com/checkpoint-restore/rust-criu

@donkomura
Which of these implementations are you interested in?

[donkomura]

@nayuta723
Thank you for your suggestions. Extending rust-criu sounds interesting, but I'd like to implement the former TODOs first.

[nayuta723]

#3429 is a simplified summary, and I haven't fully identified which parts can be implemented without extending rust-criu yet. Could you help investigate which tasks we should prioritize for the initial implementation?

Also, I’d like to move forward using an Umbrella Issue to track our progress. Could you help organize the tasks into a ToDo list or a set of issues? Feel free to structure it however works best for you!

[nayuta723]

To avoid potential conflicts, I've made sure #3429 doesn't depend on the checkpoint functionality. I will split the checkpoint feature into a separate PR from #3429.

[donkomura]

Ok, Here is a list of cli options which is implemented on runc but not implemented on youki (or unimplemented on rust-criu).

Not implemented on youki

• --manage-cgroups-mode Support manage-cgroup-mode option for checkpoint #3452

Not implemented on rust-criu (needs to expand rust-criu)

• --parent-path
• --lazy-pages
• --status-fd
• --page-server
• --pre-dump
• --empty-ns
• --auto-dedup
• --tcp-skip-in-flight
  • support in rust-criu Add tcp_skip_in_flight support checkpoint-restore/rust-criu#49
• --link-remap