How to test (from https://github.com/opencontainers/runc/pull/2352#issuecomment-620834524):
(host)$ sudo swapoff -a
(host)$ sudo ctr run -t --rm --memory-limit $((1024*1024*32)) docker.io/library/alpine:latest foo
(container)$ sh -c 'VAR=$(seq 1 100000000)'
An event `/tasks/oom {"container_id":"foo"}` will be displayed in `ctr events`.
Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
* only shim v2 runc v2 ("io.containerd.runc.v2") is supported
* only PID metrics is implemented. Others should be implemented in separate PRs.
* lots of code duplication in v1 metrics and v2 metrics. Dedupe should be separate PR.
Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
