It's easy to get update conflict when processing a DaemonSet
continuously. storeDaemonSetStatus had a retry logic that it gets the
resource from apiserver to update the DaemonSet with the latest resource
version. However, it never really retried because of a wrong check and
always made an useless get call. This patch fixes the logic to allow
the function retry once on update error.
The nodeShouldRunDaemonPod method does not need to return an error
because there are no scenarios under which it fails. Remove the
error return path for its direct calls as well.
If MaxSurge is set, the controller will attempt to double up nodes
up to the allowed limit with a new pod, and then when the most recent
(by hash) pod is ready, trigger deletion on the old pod. If the old
pod goes unready before the new pod is ready, the old pod is immediately
deleted. If an old pod goes unready before a new pod is placed on that
node, a new pod is immediately added for that node even past the MaxSurge
limit.
The backoff clock is used consistently throughout the daemonset controller
as an injectable clock for the purposes of testing.
It is too easy to omit checking the return value for the
syncAndValidateDaemonSet test in large suites. Switch the method
type to be a test helper and fatal/error directly. Also rename
a method that referenced the old name 'Rollback' instead of
'RollingUpdate'.
Automatic merge from submit-queue (batch tested with PRs 67493, 67617, 67582, 67337). 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>.
Fix bug:DaemonSet didn't create pod after node have enough resource
**What this PR does / why we need it**:
Fix bug:DaemonSet didn't create pod after node have enough resource
**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes#67225
**Special notes for your reviewer**:
NONE
**Release note**:
```release-note
DaemonSet: Fix bug- daemonset didn't create pod after node have enough resource
```
Automatic merge from submit-queue (batch tested with PRs 63580, 63744, 64541, 64502, 64100). 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>.
remove redundant getKey functions from controller tests
```release-note
None
```
