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Author SHA1 Message Date
853e62a19c
monitoring: retire the Uptime-Kuma-era checks, add ZFS pool capacity
Five things deprecated, each verified against the DEPLOYED script before being
deleted rather than assumed superseded:

  infra/410_disk_usage_alerts.yml   -> disk-usage check   (infra/400)
  infra/420_system_healthcheck.yml  -> liveness check     (infra/400)
  infra/430_cpu_temp_alerts.yml     -> cpu-temp check     (infra/400)
  32_zfs play 2 (monitoring half)   -> zfs-health check   (infra/400)
  34_nut play 2 (entirely)          -> ups-status check   (infra/400)

Nothing is lost by the swap. The old system_healthcheck.sh only computed uptime
and pushed, which is exactly a liveness heartbeat. The old disk monitor was
WEAKER than its replacement: it checked "/" alone at 80%, where the new one
walks every real filesystem at 85%.

Deleting the playbooks was not the hard part. The units they installed live on
the hosts, enabled, and keep firing regardless of what the repo says - two of
them were still pushing to uptime.contrapeso.xyz every 15 minutes across nine
machines. A playbook deleted without a cleanup leaves its output running
forever with nothing left to explain it. So infra/409_remove_legacy_monitoring
stops, disables and removes the units, deletes /opt/{disk-monitoring,
system-healthcheck,nodito-monitoring,zfs-monitoring}, and removes the orphaned
hand-written ups-heartbeat.sh. It ends by grepping for any surviving Kuma
reference and reporting it. Kept permanently and idempotent, so a rebuilt or
restored host cannot quietly bring them back.

A trap avoided: the monthly ZFS scrub lived INSIDE 32_zfs play 2. Deleting the
play wholesale would have silently stopped scrubbing the pool - and an
unscrubbed pool makes the health check meaningless, because it would have
nothing true to report. That play is now scrub-only and check-runs ok=5
changed=0.

ZFS pool capacity added as a sixth condition to the zfs-health check. `zpool
status` reports a 95% full pool as perfectly ONLINE, so capacity has to be read
separately with `zpool list` - and it is the failure you get warning of rather
than the one you discover. Threshold 80%, because ZFS allocation degrades badly
past roughly that and fragmentation is hard to undo. The pool is at 47%.
Verified both directions: passes on the real pool, and a simulated 91% exits 1.

Also fixed the waste recorded in c2de6db: the healthcheck role installed its
dependencies once per CHECK rather than per HOST - 29 apt transactions
estate-wide for a curl already present, and the slowest part of every deploy.
It now deduplicates within a play run, and the redundant standalone
daemon_reload is gone (the systemd task already does one).

site.yml updated, which exposed that services/gatus was never in it. It now runs
before the three registration playbooks, since registering endpoints against a
Gatus that is not yet serving would simply fail.

Verified: no legacy timer remains on any host; 83 endpoints, 83 UP, 0 DOWN.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-14 10:18:57 +02:00
e8eae0c3c5
ansible: add site.yml, and rename the monitoring group off the host's name
site.yml is a TABLE OF CONTENTS, not a second source of truth. It is 25
import_playbook: lines and comments - no `hosts:`, no `roles:`. Which hosts get
what stays on the `hosts:` line inside each playbook, exactly where it already
was; nothing moved. Every role is already wrapped in a thin playbook carrying
its own `hosts:` line, so there is no roles-vs-playbooks split to reconcile:
from here everything is a playbook.

What it buys:

  What runs on a host?  ansible-playbook site.yml --limit <host> --list-hosts
  Who gets thing Y?     the `hosts:` line in Y's own playbook
  What is a host?       ansible-inventory --graph

Note --list-hosts, not --list-tasks: the latter prints every play regardless of
--limit, so it will happily show you the bitcoin play under memos-box.

Nine playbooks are deliberately excluded and the file names every one with a
reason, so it accounts for all of them: the three infra/4xx monitoring plays
(still assert on the removed Uptime Kuma credentials and fail immediately),
910_docker (says `hosts: managed`, but Docker is on 5 of 11 managed hosts and
those 5 are exactly the ones that need it - running it installs Docker on the
Bitcoin node and the hypervisor), two nodito one-shots, the Kuma notification
setup, and two deliberate manual actions.

Writing it surfaced an inventory collision. There is a HOST named `monitoring`
in [vps] AND a group [monitoring], so Ansible warned and resolved `hosts:
monitoring` to the host:

  [WARNING]: Found both group and host with same name: monitoring

The group is renamed to [observability]; the host keeps its name. [caddy:children]
and the two ntfy playbooks follow. Behaviour is unchanged - `hosts: monitoring`
already resolved to the host - but the ambiguity is gone and the warning with it.

Verified: inventory graph is warning-free, site.yml passes --syntax-check, and
per-host play counts are identical before and after the rename.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-13 21:24:09 +02:00