test: Fix kubectl log retrieval
test: Fix kubectl log retrieval

After each test case, we retrieve Cilium logs to look for known-bad log
messages. Daniel recently noticed that tests containing known-bad
message logs are passing.

The issue is in the kubectl logs command we use to retrieve the logs.
Its behavior seems to have changed at some point. When used with a label
selector---as we do---the option --tail has a default value of 10
instead of -1. We are therefore only seeing the 10 last lines of each
Cilium pod, regardless of the --since option's value.

Reported-by: Daniel Borkmann <3d0f3b9ddcacec30c4008c5e030e6c13a478cb4f@iogearbox.net>
Signed-off-by: Paul Chaignon <a027184a55211cd23e3f3094f1fdc728df5e0500@cilium.io>

tklauser/cilium,cilium/cilium,cilium-team/cilium,michi-covalent/cilium,tgraf/cilium,tgraf/cilium,michi-covalent/cilium,tgraf/cilium,cilium/cilium,tklauser/cilium,cilium/cilium,tgraf/cilium,michi-covalent/cilium,tklauser/cilium,cilium-team/cilium,tgraf/cilium,tgraf/cilium,michi-covalent/cilium,cilium/cilium,michi-covalent/cilium,tklauser/cilium,tklauser/cilium,cilium/cilium