This implements the replacement of klog output to different files per level
with optionally splitting JSON output into two streams: one for info messages
on stdout, one for error messages on stderr. The info messages can get buffered
to increase performance. Because stdout and stderr might be merged by the
consumer, the info stream gets flushed before writing an error, to ensure that
the order of messages is preserved.
This also ensures that the following code pattern doesn't leak info messages:
klog.ErrorS(err, ...)
os.Exit(1)
Commands explicitly have to flush before exiting via logs.FlushLogs. Most
already do. But buffered info messages can still get lost during an unexpected
program termination, therefore buffering is off by default.
The new options get added to the v1alpha1 LoggingConfiguration with new command
line flags. Because it is an alpha field, changing it inside the v1beta kubelet
config should be okay as long as the fields are clearly marked as alpha.
The Quantity type itself cannot be used because the Set method has the wrong
signature. Embedding Quantity inside a new QuantityValue type makes it possible
to inherit most of the methods while overriding the Set method.
Moving the registry into its own package will avoid dependency cycles in future
PRs.
Creating loggers through a factory instead of storing pre-created instances
will make it possible to create the loggers differently depending on
configuration parameters.
The factory can also be used to provide additional meta data before creating
instances.
The name concatenation and ownership check were originally considered small
enough to not warrant dedicated functions, but the intent of the code is more
readable with them.
There also was a missing owner check in the attach controller.
The name concatenation and ownership check were originally considered small
enough to not warrant dedicated functions, but the intent of the code is more
readable with them.
During volume detach, the following might happen in reconciler
1. Pod is deleting
2. remove volume from reportedAsAttached, so node status updater will
update volumeAttached list
3. detach failed due to some issue
4. volume is added back in reportedAsAttached
5. reconciler loops again the volume, remove volume from
reportedAsAttached
6. detach will not be trigged because exponential back off, detach call
will fail with exponential backoff error
7. another pod is added which using the same volume on the same node
8. reconciler loops and it will NOT try to tigger detach anymore
At this point, volume is still attached and in actual state, but
volumeAttached list in node status does not has this volume anymore, and
will block volume mount from kubelet.
The fix in first round is to add volume back into the volume list that
need to reported as attached at step 6 when detach call failed with
error (exponentical backoff). However this might has some performance
issue if detach fail for a while. During this time, volume will be keep
removing/adding back to node status which will cause a surge of API
calls.
So we changed to logic to check first whether operation is safe to retry which
means no pending operation or it is not in exponentical backoff time
period before calling detach. This way we can avoid keep removing/adding
volume from node status.
Change-Id: I5d4e760c880d72937d34b9d3e904ecad125f802e
