#5834 "The host agent is always on, and the MCP sees a host's
maintenance", step 1 of milestone 520 "The MCP sees what Steward has
grown".
The host agent is a core system (operator, 2026-10-15: "it's very core
to the functionality of Steward as a whole and shouldn't be considered
something that can be toggled off"). ALWAYS_ON_PLUGINS in core settings
makes to_plugins_cfg report it enabled whatever its stored row says, so
it always loads and its MCP tools are always listed. Settings -> Plugins
shows it as "Built in: always on" with no switch, and a save keeps it
enabled. Its code and URLs stay under plugins/host_agent: every
installed agent posts to /plugins/host_agent/ingest.
Maintenance through the MCP:
- list_maintenance_plans: each plan's group, weekly slot, reboot policy,
next slot, and its latest run (hosts, how far it got, who it skipped
and why, how it ended).
- get_maintenance_job(host | job): a host's jobs, newest and running
first, or one job: state, packages updated, reboot, drained by, why it
failed, when its current state times out.
- run_maintenance(host, reboot="if_required" | "never"): admin, as the
host page's Update now; refuses a busy host or one with no helper;
audited "<user> via MCP".
- The overview names a host whose latest job in the last week failed or
timed out.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
MCP-5 of milestone 461 "MCP server: Steward as an LLM-inspectable,
LLM-operable hub". Contributed through each plugin's register_mcp_tools
hook, so they exist only while the plugin is enabled.
docker (viewer, read-only):
- list_containers: filter by host, status, compose project, or problem
(restarting, crash_looping, unhealthy, oom_killed, exited_nonzero);
problems sort first and each row names what is wrong.
- get_container: state, CPU/memory history across the raw/hourly seam,
lifecycle events. A unique part of a swarm task name is enough.
- list_swarm_services: replicas per node (agent-less placements as ghosts)
and the swarm's nodes.
- search_container_logs: text (% and _ literal), stream, range, context
lines, paging by a full-precision `before` cursor; over-long lines keep
both ends and say how much of the middle was cut.
- get_docker_disk_usage: bytes per host, reclaimable first.
- mcp_overview: failing containers and under-replicated swarm services
join get_overview.
host_agent: list_agents (reporting / stale / pending, version, OS), and an
overview finding for agents registered over 30 minutes ago that never
checked in.
Settings > Thresholds gains the TLS-expiry warn/crit days (were 14/3 in
code) and the crash-loop deaths-per-hour count (3), which get_overview
and the docker tools now read.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
bvandeusenandClaude Opus 5.5