Automatic merge from submit-queue (batch tested with PRs 50536, 50809, 50220, 50399, 50176)
Refactor statefulset test with sets.String
**What this PR does / why we need it**:
Delete redundant sort. These string slices only own one element.
There is no necessary to sort them.
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #
**Special notes for your reviewer**:
**Release note**:
```release-note
NONE
```
Implements history utilities for ControllerRevision in the controller/history package
StatefulSetStatus now has additional fields for consistency with DaemonSet and Deployment
StatefulSetStatus.Replicas now represents the current number of createdPods and StatefulSetStatus.ReadyReplicas is the current number of ready Pods
The GC expects that once it sees a controller with a non-nil
DeletionTimestamp, that controller will not attempt any adoption.
There was a known race condition that could cause a controller to
re-adopt something orphaned by the GC, because the controller is using a
cached value of its own spec from before DeletionTimestamp was set.
This fixes that race by doing an uncached quorum read of the controller
spec just before the first adoption attempt. It's important that this
read occurs after listing potential orphans. Note that this uncached
read is skipped if no adoptions are attempted (i.e. at steady state).
1. pcb and pcb controller are removed and their functionality is
encapsulated in StatefulPodControlInterface.
2. IdentityMappers has been removed to clarify what properties of a Pod are
mutated by the controller. All mutations are performed in the
UpdateStatefulPod method of the StatefulPodControlInterface.
3. The statefulSetIterator and petQueue classes are removed. These classes
sorted Pods by CreationTimestamp. This is brittle and not resilient to
clock skew. The current control loop, which implements the same logic,
is in stateful_set_control.go. The Pods are now sorted and considered by
their ordinal indices, as is outlined in the documentation.
4. StatefulSetController now checks to see if the Pods matching a
StatefulSet's Selector also match the Name of the StatefulSet. This will
make the controller resilient to overlapping, and will be enhanced by
the addition of ControllerRefs.
