Previously, if a write or sync error occurred, we would not have called
Close(). This commit refactors ReplaceFile() so that we are sure to call
Close(), and also attempts to delete the temporary file if errors occur.
Automatic merge from submit-queue
fsync config checkpoint files after writing
@yujuhong brought up that it's possible for a hard reboot to result in empty checkpoint files, if they haven't been synced to disk yet. This PR ensures that Kubelet configuration checkpoints are synced after writing to avoid this issue.
fixes#52222
**Release note**:
```release-note
NONE
```
Rather than just changing the config once to see if dynamic kubelet
config at-least-sort-of-works, this extends the test to check that the
Kubelet reports the expected Node condition and the expected configuration
values after several possible state transitions.
Additionally, this adds a stress test that changes the configuration 100
times. It is possible for resource leaks across Kubelet restarts to
eventually prevent the Kubelet from restarting. For example, this test
revealed that cAdvisor's leaking journalctl processes (see:
https://github.com/google/cadvisor/issues/1725) could break dynamic
kubelet config. This test will help reveal these problems earlier.
This commit also makes better use of const strings and fixes a few bugs
that the new testing turned up.
Related issue: #50217
Automatic merge from submit-queue (batch tested with PRs 51805, 51725, 50925, 51474, 51638)
Flexvolume dynamic plugin discovery: Prober unit tests and basic e2e test.
**What this PR does / why we need it**: Tests for changes introduced in PR #50031 .
As part of the prober unit test, I mocked filesystem, filesystem watch, and Flexvolume plugin initialization.
Moved the filesystem event goroutine to watcher implementation.
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes#51147
**Special notes for your reviewer**:
First commit contains added functionality of the mock filesystem.
Second commit is the refactor for moving mock filesystem into a common util directory.
Third commit is the unit and e2e tests.
**Release note**:
```release-note
NONE
```
/release-note-none
/sig storage
/assign @saad-ali @liggitt
/cc @mtaufen @chakri-nelluri @wongma7
The subfeature was a cool idea, but in the end it is very complex to
separate Kubelet restarts into crash-loops caused by config vs.
crash-loops caused by other phenomena, like admin-triggered node restarts,
kernel panics, and and process babysitter behavior. Dynamic kubelet config
will be better off without the potential for false positives here.
Removing this subfeature also simplifies dynamic configuration by
reducing persistent state:
- we no longer need to track bad config in a file
- we no longer need to track kubelet startups in a file
This reverts commit f4afdecef8, reversing
changes made to e633a1604f.
This also fixes a bug where Kubemark was still using the core api scheme
to manipulate the Kubelet's types, which was the cause of the initial
revert.
Michael Taufen