#5464 "Group rules: one rule covers every host, or every host in a group",
step 2 of milestone 499 "Alerts you can trust". Each rule named one host, so
the live instance carried six rules for three hosts, and a new host had no
agent-offline or disk alert until someone copied them.
- alert_rules.covers / cover_group / parent_id (migration 0041). A rule on
host_agent may cover "all_hosts" or a "group" (an inventory group: the
Hosts ruling, #5294). A covering rule has no state; Steward keeps one
ordinary child rule per covered host, named "<rule>: <host>", so each
host's alert keeps its own state, history and acknowledgement.
- alerts.service.reconcile_children: a covered host that has reported in
the last 7 days gets a child; a host no longer covered loses its child;
children take the parent's condition, checks, notify setting, action and
on/off. Run on save and each minute (alert_reconcile).
- A child is changed through its parent: edit, toggle and delete of a child
are refused (409 / PartOfCoveringRule); its edit page opens the parent.
- Rule form: a Covers choice for host sources, with the group picker; fixed
once the rule exists. Rules list: a covering rule reads "every host in
swarm · 3 hosts" with its hosts' rules nested under it, each opening its
history. The history picker and the rule count leave covering rules out.
- MCP: create_alert_rule takes covers/group; update_alert_rule takes group
and passes changes down; list_alert_rules shows covers, hosts and part_of.
- docs/core/alerting.md: "Rules that cover hosts".
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
