Feature: shim: Complete the metrics collection for cgroup v1

[zzzzzzzzzy9]

Complete the metrics collection for cgroup v1 so that containerd can obtain complete metrics information

[zzzzzzzzzy9]

@mxpv

[zzzzzzzzzy9]

@Burning1020

[Burning1020]

Got you. Will review it...

[Mossaka]

I think it's great to have a complete cgroupv1 stats collection, but given #258 suggests that the complex logic of cgroups stats should not reside in the shim crate, I would recommend that we should take a look at if libcgroups could be of use.

In particular, libcgroups maintained by youki has cgroups v1 and v2 StatsProvider (source), so we don't need to duplicate the effort in this repo.

I am fully aware that we are using cgroups-rs, so what I am proposing here is to evaluate whether or not libcgroups satisfies our requirements and can replace cgroups-rs.

CC @utam0k

[utam0k]

I'm happy to collaborate with you if possible!

[mxpv]

Hey @Mossaka, can you give a bit more context on cgroups-rs vs libcgroups ?