As seen in https://github.com/kubernetes/kubernetes/issues/102452, we
currently don't have pod events for the CSI driver pods because of the
different namespace and would need them to determine whether the
driver gets evicted.
Previously, only changes of the pods where logged. Perhaps even more
interesting are events in the namespace.
The existing function in podlogs is copyAllLogs from a namespace. Add a
new function to copy log from a single pod.
Change-Id: I39d139a2a57d72a0af3432626b0c02c1b43333d2
Because log capturing can end due to an error and because a pod has
terminated, it is uncertain whether all log output has been
captured. So far, the code leaned more towards restarting log
capturing based on the rationale that duplicate logs are better than
no logs.
But this is confusing and potentially makes logs much larger, so now
an additional heuristic is used to avoid log capturing when logging
was started already and the pod itself is marked for deletion. That
occurs before the individual containers shut down and get marked as
terminated.
The original logic was that dumping can stop (for example, due to
loosing the connection to the apiserver) and then will start again as
long as the container exists. That it duplicates output on restarts
is better than skipping output that might not have been dumped yet.
But that logic then also dumped the output of containers that have
terminated multiple times:
- logging is started, dumps all output and stops because the
container has terminated
- next check finds the container again, sees no active logger,
repeats
This wasn't a problem for short-lived logging in a custom
namespace (the way how it is done for CSI drivers in Kubernetes E2E),
but other testsuites (like the one from PMEM-CSI) keep logging running
for the entire test suite duration: there duplicate output became a
problem when adding driver redeployment as part of the suite's run.
To avoid duplicated output for terminated containers, which containers
have been handled is now stored permanently. For terminated containers,
restarting of dumping is prevented. This comes with the risk that if
the previous dumping ended before capturing all output, some output
will get lost.
Marking the start and stop of the log was also useful when streaming
to a single writer and thus gets enabled.
The e2e framework package podlogs is used in e2e/storage/testsuites
only. In addition we considered we should have a single e2e framework
package for pod without the podlogs. So this moves the podlogs into
e2e/storage/podlogs for the e2e storage tests.
