pod_on_node turns its node argument into `--field-selector
spec.nodeName=<node>`, and an empty node asks for pods whose nodeName is
empty -- the unscheduled ones. So an unidentified node did not yield "no
pod found": it yielded the first pending kube-ovn-cni pod in the
namespace, and the tcpdump then ran against a pod that is not on that
node and may not be running at all.
Both halves of the cross-node capture had this, and each gap opens in
the very state its own leg exists to characterise. The announcer is
unknown exactly when MetalLB is misbehaving; a Service with no ready
endpoint is the ordinary shape of an LB outage, and the endpoint side
carried two such lookups, the cni-server pod and the backend's OVS
interface. In either state the artifact came out holding a tcpdump from
an unrelated pending pod under an ANNOUNCER or ENDPOINT label, or a
confusing exec failure -- both pointing away from the actual problem.
Each leg is now guarded the way the static capture above it already was,
and records in the artifact that it was skipped rather than leaving a
silent gap. The guards stay at the call sites rather than moving into
pod_on_node: that helper serves five callers, and an early return there
would have to invent a status for a lookup nobody made.
Assisted-By: Claude <noreply@anthropic.com>
Signed-off-by: Aleksei Sviridkin <f@lex.la>
Aleksei Sviridkin
33f672f3fc