The agent (1.9.0) said nothing when Docker could not be asked and nothing
when Docker had no containers, so Steward could tell neither apart from the
other, and kept a host's last containers on screen as running either way.
- Agent: collect_docker returns (status, detail, containers). "ok" sends
docker: [] when there are none; "unavailable" (no socket, nothing
listening) and "error" (permission, timeout, bad answer) say why.
collect_swarm says whether /info answered, and a node that is not a
manager sends swarm_manager: false. A failed /info says nothing.
- Ingest: an empty docker list is a snapshot; the newest sample's status
goes to the Docker plugin with the rest.
- docker_host_status (docker_011): per host, status, detail, since and
last report. A host that never had Docker gets no row.
- An "ok" empty snapshot reaps the host's containers; an error keeps them.
swarm_manager: false drops the host's swarm services and nodes.
- Docker page: a "Docker not answering" card names each such host, why,
and since when; its containers read as stale. Duplicate header comment
in rows.html removed.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>