Three changes: detection windows tightened, a Signal transport deployed, and
alerts attached to all 84 non-transport endpoints.
── Failing faster ──────────────────────────────────────────────────────────
The heartbeat is a TICKER, not a deadline: Gatus wakes every interval and asks
"did anything arrive in the last interval", so real detection is 1-2x the
window. And a window can only ever be as tight as the push frequency - which is
why two checks moved rather than just having their numbers changed.
liveness, cpu, ups, service-health, probes 16m -> 11m
disk, zfs daily/30h -> 6-hourly/7h
backup store + pull job daily/30h -> 6-hourly/7h
DNS records 24h -> 6h
backup dump 30h -> 26h
backup-dump stays slow because the dump genuinely is daily. The store-side check
catches the same fault within 6h by reading the source's dump timestamp out of
the artefact filename, so 26h is a backstop rather than the primary signal.
── Thresholds differ by check type, deliberately ───────────────────────────
`failure-threshold` counts consecutive failures, but "consecutive" is a
different amount of wall-clock time per check: a push endpoint produces one
failure per heartbeat window, a pulled one per interval. The default of 3 would
mean 33 minutes on an 11m heartbeat and over a day on a 7h one.
More importantly the heartbeat window ALREADY encodes the tolerance - an 11m
window on a 5-minute push is exactly "one missed push forgiven" - so stacking a
threshold of 3 triples a tolerance that was already chosen. Hence:
push/heartbeat endpoints failure-threshold 1
pulled, 5m (public) failure-threshold 3 (= 15 minutes)
pulled, 6h/24h (dns, domain) failure-threshold 1
── The Signal transport ────────────────────────────────────────────────────
roles/signal_api runs signal-cli-rest-api on the observability host, pinned by
digest, MODE=native.
It publishes NO PORTS. The API has no authentication of any kind - anything that
reaches it can send messages as you and read your Signal. Gatus talks to it over
a shared docker network by service name, which is also WHY the network exists:
Gatus runs in a container, so the host's loopback is unreachable from it and a
port published on 127.0.0.1 would not have worked.
MODE=native and not json-rpc because this VPS has 464MB of RAM and already runs
Gatus and Caddy. The json-rpc modes hold a resident JVM; native runs a binary
per request, and alerts are rare enough that startup cost per alert is the right
trade.
Monitored - Gatus polls /v1/health over the same network path the alerts take,
so it proves the delivery route rather than mere container liveness. Deliberately
NOT backed up: the data directory holds Signal private keys and the recovery
path is to link the device again from the phone.
Neither the signal-api endpoint nor Gatus's self-check carries a Signal alert.
If either is down, Signal is precisely what cannot deliver the alert.
── Four traps hit while linking, all now in the role README ────────────────
* /v1/qrcodelink is BROKEN in native mode - returns "no data to encode" while
the binary itself emits a perfectly good URI. Not worked around by switching
MODE, which would put a JVM in the path of every alert permanently.
* The data dir must be owned by uid 1000, not root. A root-owned 0700 dir
cannot be traversed by the container user, so linking silently never
completes and /v1/accounts returns "Failed to read local accounts list".
* `docker exec` runs as ROOT while the service runs as uid 1000, so without
--config the account is written to /root/... on the container's ephemeral
layer. It reports success and is destroyed on the next recreate.
* The phone reporting "network error" was IPv6: chat.signal.org resolves to
dualstack AAAA records first, the container has no IPv6 address, and this
host's IPv6 path is broken - the same edge that 404'd the Go tarball. Fixed
with a mounted gai.conf that prefers IPv4.
Verified: provider loads (configuredProviders=[signal]), a test message was
delivered and confirmed received, 84 endpoints carry alerts, 86 UP / 0 DOWN.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Nothing in the repo pushes to, authenticates against, or is gated by Uptime
Kuma any more.
── The sixth instance of the banner bug ────────────────────────────────────
memos had `Restart memos` guarded by `uptime_kuma_enabled`, because the
deprecation banner was placed immediately above it and swept it in. It is a
HANDLER, so every memos config change since 2026-09-11 applied to disk and
silently never restarted the service. Ungated.
That is the same failure found in forgejo-runner's self-assert, phoenixd's timer
enable, mempool's three timer enables, fulcrum's restart handler and bitcoind's
restart handler. Every guard was read and asked "monitoring or deployment?"
before being deleted, which is the only reason this was caught.
── What was removed ────────────────────────────────────────────────────────
30 uptime_kuma_enabled guards across 7 unconverted service playbooks, and
the 29 Kuma monitor-creation tasks they gated (embedded Python that drove
the Kuma API, temp credential files, cleanup)
7 dead uptime_kuma_api_url definitions
7 stale DEPRECATED banners
uptime_kuma_enabled and subdomains.uptime_kuma from group_vars/all
healthcheck_push_urls from the vault - 30 push tokens
services/ntfy/setup_ntfy_uptime_kuma_notification.yml -> archive/
The explanatory comments in the six converted roles are KEPT on purpose. They
record why a handler is ungated, and deleting the explanation invites someone
to helpfully re-add the guard.
── The probes moved rather than died ───────────────────────────────────────
Eight per-service health checks were still pushing to Kuma. They are not
superseded by infra/401: that answers "is the unit running", these answer "does
the service actually respond" - an RPC call to bitcoind, a TCP connect to
Fulcrum's Electrum port, an HTTP fetch from Mempool's backend. A process can be
perfectly `active` and useless.
So they were repointed, not deleted. Gatus external endpoints take a POST with
a bearer token and success=true|false where Kuma took a GET with ?status=up, so
report() now maps up/down to true/false internally and no call site changed.
Registered by infra/403 as the `probe` group, one token per host.
Two bugs fixed while in there:
* forgejo-runner's check only ever reported SUCCESS - it exited before pushing
when the runner was down, so a failure was invisible until the heartbeat
window expired. Reporting the failure is the entire point of a check.
* All six healthcheck .service units were mode 0644 and now carry a bearer
token. They are 0600.
Verified: 91 endpoints, 91 UP, 0 DOWN. Every probe triggered by hand and
confirmed arriving. Zero Kuma URLs left in the vault, zero live references in
any playbook or role.
Still standing, deliberately: the Kuma container on watchtower, its Caddy vhost,
and the uptime.contrapeso.xyz DNS record. Turning the service off is a separate
decision from removing the code that talked to it.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
