+ // What we tell docker to use as the container's cgroup
+ // parent. Note: Ideally we would use the same field for both
+ // expectCgroupParent and setCgroupParent, and just make it
+ // default to "docker". However, when using docker < 1.10 with
+ // systemd, specifying a non-empty cgroup parent (even the
+ // default value "docker") hits a docker bug
+ // (https://github.com/docker/docker/issues/17126). Using two
+ // separate fields makes it possible to use the "expect cgroup
+ // parent to be X" feature even on sites where the "specify
+ // cgroup parent" feature breaks.
+ setCgroupParent string