Use cgroup tools instead of file system access so that it works regardless of how cgroups was bootstrapped or configured.
The resulting code will be identical on RHEL 6 and F17/F18 and does not require branching
1. libcgroup (RHEL6, F17, F18, etc...) and libcgroup-tools (F17, F18)
2. lssubsys to determine the set of cgroups subsystems.
2.a. Check that the requirements for Openshift are met.
3. Continue to populate /etc/cgrules.conf using the same format we do today.
4. On RHEL 6, continue to manage /etc/cgconfig.conf on Hosted and Enterprise but don't touch it on F17/F18.
5. Use lscgroup to determine if a gear has cgroups
6. Use cgget and cgset to access gear cgroup parameters.
cgget -r cpu.cfs_period_us /openshift/3d1131c867dd4dabbe814d037fdcd3ec