[MESOS-7969] Handle cgroups v2 hierarchy when parsing /proc/self/cgroups.

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.2.3, 1.3.2, 1.4.1, 1.5.0
• Fix Version/s: 1.2.3, 1.3.2, 1.4.1, 1.5.0
• Sprint: Mesosphere Sprint 63
• Story Points: 1
• Assignee: Kapil Arya
• Reporter: Kapil Arya
• Created: 12/Sep/17 18:05
• Updated: 14/Dec/17 21:29
• Resolved: 13/Sep/17 19:38

Description

Cgroups v2 hierarchies don't list the "controllers" field (e.g., "0::/user.slice/user-1000.slice/session-5.scope) is empty [1] and hence the cgroup parser failes. We should simply skip over fields with empty controller field.

[ RUN      ] CgroupsAnyHierarchyTest.ROOT_CGROUPS_Read
../../src/tests/containerizer/cgroups_tests.cpp:464: Failure
cgroup: Unexpected format in /proc/20668/cgroup
[  FAILED  ] CgroupsAnyHierarchyTest.ROOT_CGROUPS_Read (8 ms)

[1] See 6-2 in https://www.kernel.org/doc/Documentation/cgroup-v2.txt