OOMWatcher does not detect victim container correctly on some OSs

[dashpole]

Linux 5.0
Ubuntu 18.04

The OOM Parser code looks for Task in (.*) killed as a result of limit of (.*), which doesn't seem to match what this kernel is putting out...

I am seeing:

[180042.118480] oom-kill:constraint=CONSTRAINT_MEMCG,nodemask=(null),cpuset=ef807430361e6e82b45db92e2e9b6fbec98f419b12c591e655c1a725565e73a8,mems_allowed=0,oom_memcg=/kubepods/burstable/podfbdfe8e3-1c87-4ff2-907
c-b2ec8e25d012,task_memcg=/kubepods/burstable/podfbdfe8e3-1c87-4ff2-907c-b2ec8e25d012/ef807430361e6e82b45db92e2e9b6fbec98f419b12c591e655c1a725565e73a8,task=manager,pid=966,uid=0

instead.

This causes all OOMs to be reported as system OOMs, since we default the ContainerName and VictimContainerName to "/".

[dashpole]

Looks like this is a change in 5.0 kernels:

torvalds/linux@f0c867d#diff-c14acc69885a24f354bc607686800e23

cc @derekwaynecarr @sjenning