Automatic merge from submit-queue (batch tested with PRs 54773, 52523, 47497, 55356, 49429). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
Deduplicate RC/RS controller code.
The code was already 99% similar between RC and RS. This is a wild idea to try to deduplicate the two controllers in a type-safe manner without adding tons of boilerplate, and without using code generation.
They are still separate resources and separate worker pools. This is a refactor that isn't intended to change any behavior.
```release-note
ReplicationController now shares its underlying controller implementation with ReplicaSet to reduce the maintenance burden going forward. However, they are still separate resources and there should be no externally visible effects from this change.
```
ref #49429
The code was already 99% similar between RC and RS.
This is a wild idea to try to deduplicate the two controllers
in a type-safe manner without adding tons of boilerplate,
and without using code generation.
They are still separate resources. This is a refactor that isn't
intended to change any behavior.
Prevent too-large replicas from generating enormous numbers
of events by creating only a few pods at a time, then increasing
the batch size when pod creations succeed. Stop creating batches
of pods when any pod creation errors are encountered.
Automatic merge from submit-queue (batch tested with PRs 48976, 49474, 40050, 49426, 49430)
Remove duplicated import and wrong alias name of api package
**What this PR does / why we need it**:
**Which issue this PR fixes**: fixes#48975
**Special notes for your reviewer**:
/assign @caesarxuchao
**Release note**:
```release-note
NONE
```
We were comparing the address of the old and new RC.spec.replicas and we
have to compare the values. This only affects logging.
Update RS controller to match RC controller to log when spec.replicas
changes, not status.replicas.
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).
To prepare for implementing ControllerRef across all controllers,
this pushes the common adopt/orphan logic into ControllerRefManager
so each controller doesn't have to duplicate it.
This also shares the adopt/orphan logic between Pods and ReplicaSets,
so it lives in only one place.
Mikhail Mazurskiy