Patrick Ohly b9c5c55c09 podlogs: avoid dumping a terminated container more than once ...

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.

2020-04-03 14:45:00 +02:00

..

BUILD

…

podlogs.go

podlogs: avoid dumping a terminated container more than once

2020-04-03 14:45:00 +02:00