Previously, callers of `Exists()` would not know why the cGroup was or
was not existing. In one call-site in particular, the `kubelet` would
entirely fail to start if the cGroup validation did not succeed. In
these cases we MUST explain what went wrong and pass that information
clearly to the caller. Previously, some but not all of the reasons for
invalidation were logged at a low log-level instead. This led to poor
UX.
The original method was retained on the interface so as to make this
diff small.
Signed-off-by: Steve Kuznetsov <skuznets@redhat.com>
Fix an issue in which, when trying to specify the `--kube-reserved-cgroup`
(or `--system-reserved-cgroup`) with `--cgroup-driver=systemd`, we will
not properly convert the `systemd` cgroup name into the internal cgroup
name that k8s expects. Without this change, specifying
`--kube-reserved-cgroup=/test.slice --cgroup-driver=systemd` will fail,
and only `--kube-reserved-cgroup=/test --crgroup-driver=systemd` will succeed,
even if the actual cgroup existing on the host is `/test.slice`.
Additionally, add light unit testing of our process from converting to a
systemd cgroup name to kubernetes internal cgroup name.
- Move from the old github.com/golang/glog to k8s.io/klog
- klog as explicit InitFlags() so we add them as necessary
- we update the other repositories that we vendor that made a similar
change from glog to klog
* github.com/kubernetes/repo-infra
* k8s.io/gengo/
* k8s.io/kube-openapi/
* github.com/google/cadvisor
- Entirely remove all references to glog
- Fix some tests by explicit InitFlags in their init() methods
Change-Id: I92db545ff36fcec83afe98f550c9e630098b3135
