20 KiB
Thermograph — observability
Fleet-wide log aggregation for Thermograph: a central
Grafana + Loki stack, fed by a Grafana Alloy agent on every node, all
over the private WireGuard mesh. This replaces the old in-repo
scripts/dashboard.py (an SSH-tailed, single-host, metrics-endpoint view) with a
persistent, queryable, fleet-wide log store and UI.
vps1 (10.10.0.2) vps2 (10.10.0.1) desktop (10.10.0.3)
┌───────────────────────┐ ┌───────────────────────┐ ┌──────────────┐
│ Loki ◀───── Alloy │◀──wg0───┤ Alloy agent │◀─wg0──┤ Alloy agent │
│ Grafana (Caddy) │ │ prod + beta (Swarm) │ │ (no app │
│ dev (compose) │◀──wg0───┤ Postfix, backups │ │ stack) │
│ Forgejo, portfolio │ └───────────────────────┘ └──────────────┘
└───────────────────────┘ docker+caddy+app logs ships no app logs
central store + UI + dev
- vps1 is the monitoring host: Loki, Grafana, Forgejo, the portfolio site, and the dev environment (its own compose project, mesh-only, no public DNS). It does not run the beta environment — that now lives on vps2 — so any older doc that says "beta" meaning this box is stale and needs reading as vps1.
- vps2 runs prod and beta as two separate Docker Swarm stacks
(
thermograph,thermograph-beta), plus Postfix and backups. One shared TimescaleDB serves both, on separate roles/databases. - desktop hosts no Thermograph environment now (AI-model hosting + flex Swarm-worker capacity instead), so it ships no app logs.
- Loki stores logs (filesystem, 30-day retention). Listens on the mesh IP
10.10.0.2:3100— never public. - Grafana is the UI, fronted by vps1's Caddy at
dashboard.thermograph.org, login via Google SSO (with a break-glass local admin); Loki is not exposed. - Alloy runs on each node and ships three sources to Loki: every Docker
container's stdout/stderr, Caddy's host access logs, and the app's structured
JSON logs (
errors/access/audit*.jsonl, parsed solevel/tag/phasebecome labels). Every line now carries two distinct labels:host(prod|beta|dev) is the ENVIRONMENT, derived per source (a container's stack prefix, the Caddy access-log filename, or whichapplogsvolume a JSON line came out of) — because vps2 alone carries two environments, and one node-wide value would have stamped every beta container and log line asprod.node(vps1|vps2|desktop) is the MACHINE, stamped externally on everything an agent ships. Seealloy/config.alloyfor exactly howhostis derived per source.
Layout
| Path | What |
|---|---|
docker-compose.yml |
the central Loki + Grafana stack (runs on vps1) |
loki/config.yml |
Loki config (filesystem, retention) |
grafana/provisioning/ |
auto-wired Loki datasource + dashboard provider |
grafana/provisioning/alerting/ |
contact point, notification policy and alert rules — see Alerting |
grafana/dashboards/thermograph-logs.json |
the fleet-logs dashboard |
alloy/config.alloy |
the per-node collector config |
alloy/docker-compose.agent.yml |
runs the Alloy agent on a node |
alloy/docker-compose.agent.beta.yml |
overlay adding beta's applogs mount — vps2 only |
caddy-grafana.conf |
vps1 Caddy site block for the Grafana UI |
Deploy
⚠️ Merging is not deploying
/opt/observabilityon vps1 (and vps2) is a checkout of the archivedemi/thermograph-observabilityrepo. It can nevergit pullagain — the content now lives here, in the mono repo, underobservability/. A previous observability PR merged and had zero live effect for exactly this reason.Until someone re-points those checkouts at the mono repo, every change here ships by hand: back up the live file with a UTC-timestamped suffix,
scpthe new one up,sudo cpit into place, restart the specific container. Usesudo docker restart <container>— notdocker compose, which on vps2 demands aGF_SECURITY_ADMIN_PASSWORDit has no.envto interpolate from (vps2 only runs the Alloy agent — there's no Grafana there to configure). (vps1's stack does have an.env, so compose works there — and is required when a change adds a new environment variable, sincedocker restartalone will not pick one up.)
1. Central stack (on vps1)
# on vps1 (75.119.132.91):
git clone <this repo> thermograph-observability && cd thermograph-observability
cp .env.example .env # set GF_SECURITY_ADMIN_PASSWORD
docker compose up -d # Loki on 10.10.0.2:3100 + 127.0.0.1:3100; Grafana on 127.0.0.1:3000
Expose the Grafana UI: point dashboard.thermograph.org at vps1, append
caddy-grafana.conf to /etc/caddy/Caddyfile, systemctl reload caddy.
Google SSO (Grafana + Forgejo)
Both the dashboard and Forgejo log in with Google. Create one Google Cloud OAuth 2.0 Client (type: Web application) and register both redirect URIs:
- Grafana:
https://dashboard.thermograph.org/login/google - Forgejo:
https://git.thermograph.org/user/oauth2/google/callback
Grafana: put the client id/secret in .env, set OAUTH_ENABLED=true, and
docker compose up -d. Login is locked to pre-provisioned accounts
(allow_sign_up=false), so provision your email as an admin once:
# on vps1, after the stack is up (uses the break-glass admin creds from .env):
curl -s -u admin:"$GF_SECURITY_ADMIN_PASSWORD" -H 'Content-Type: application/json' \
-X POST http://127.0.0.1:3000/api/admin/users \
-d '{"name":"you","login":"you@gmail.com","email":"you@gmail.com","password":"'"$(openssl rand -base64 24)"'"}'
# then make that user a Grafana admin (org role Admin + server admin) via the UI
# or /api/org/users; the Google login matches on email.
Forgejo: add the Google auth source (once, as a Forgejo admin):
docker exec -u git <forgejo-container> forgejo admin auth add-oauth \
--name google --provider openidConnect \
--key "<CLIENT_ID>" --secret "<CLIENT_SECRET>" \
--auto-discover-url https://accounts.google.com/.well-known/openid-configuration
2. Alloy agent (on vps1 and vps2)
ALLOY_NODE names the MACHINE now, not the environment — vps2 alone runs two
environments (prod and beta), so a node name can no longer stand in for a
host value. ALLOY_ENV supplies the default environment label for anything
on that node not attributable to a specific stack (Forgejo, Grafana, the
portfolio site). APPLOGS_VOLUME is the node's primary applogs volume; vps2
additionally needs BETA_APPLOGS_VOLUME and a second compose file, since it
carries both environments' structured logs side by side.
Every node pushes to Loki over the mesh IP — a containerized agent can't reach
the host's 127.0.0.1, but it can reach vps1's wg0 address at
10.10.0.2:3100.
cd thermograph-observability/alloy
# vps1 (dev + Forgejo + the monitoring stack itself):
ALLOY_NODE=vps1 ALLOY_ENV=dev APPLOGS_VOLUME=thermograph-dev_applogs \
LOKI_URL=http://10.10.0.2:3100/loki/api/v1/push \
docker compose -f docker-compose.agent.yml up -d
# vps2 (prod + beta) — note the SECOND file, adding beta's log volume:
ALLOY_NODE=vps2 ALLOY_ENV=prod APPLOGS_VOLUME=thermograph_applogs \
BETA_APPLOGS_VOLUME=thermograph-beta_applogs \
LOKI_URL=http://10.10.0.2:3100/loki/api/v1/push \
docker compose -f docker-compose.agent.yml -f docker-compose.agent.beta.yml up -d
The mesh must already be up (see the main repo's deploy/swarm/ / INFRA.md);
Swarm is not required for the agent itself — it talks plain HTTP over wg0.
Verify
# From any mesh node, confirm Loki is receiving from every environment
# (host = prod|beta|dev; a separate node/vps1|vps2|desktop label exists too):
curl -s 'http://10.10.0.2:3100/loki/api/v1/label/host/values' # -> {"data":["beta","dev","prod"]}
# Then open Grafana → the "Thermograph — Fleet Logs" dashboard.
The dashboard
Thermograph — Fleet Logs (auto-provisioned), with a Node selector:
log volume by service, app error rate by tag, upstream 429 count, Caddy 5xx
count, a per-node notifier-liveness indicator (from the heartbeat log), recent app errors, and a live all-container
tail. Edit it in Grafana and re-export the JSON here to version a change.
Alerting
Provisioned from grafana/provisioning/alerting/, mounted read-only into Grafana
by the compose file, so the repo is the only durable path — as with the
dashboards, edits made in the Grafana UI are overwritten on the next provision.
Every rule is LogQL, because there is no Prometheus in the fleet: Loki is the only datasource, so every signal is derived from log lines.
Where alerts go: Discord, not email
#ops-alerts (Owners category, private to Emi and Jin) via Grafana's native
Discord contact point. Deliberately not email:
- Grafana's factory default pointed at the literal string
<example@email.com>— a paging path that had never delivered a message to anyone. - vps1's Grafana relays SMTP through vps2's Postfix at
10.10.0.1:25(seedocker-compose.override.ymlon vps1). Email alerts therefore travel through the box most likely to be on fire, and vanish exactly when they matter. - Discord is off-estate, works when prod is dead, and reaches a phone.
#ops-alerts is a new dedicated channel, not one of the existing ones: the
#dev / #uat / #prod channels are the product's alert-subscription output
(real deliveries — routing ops noise there would corrupt the evidence), and
#notes / #staff-chat are for humans.
The webhook URL is a secret and is not in this repo: it comes from
DISCORD_ALERT_WEBHOOK_URL in vps1's gitignored .env, which compose passes to
Grafana and which Grafana interpolates when reading the provisioning file.
Grafana refuses to start if it is unset.
The rules
| Rule | Fires when | Severity |
|---|---|---|
ProdEdgeDark |
zero prod Caddy log lines in 15m — site dark, or the log pipeline is broken | critical |
ProdHealthzFailing |
any non-200 on /healthz in 10m |
critical |
ProdHTTP5xxBurst |
≥10 prod 5xx in 10m | critical |
ProdHTTP5xxElevated |
≥25 prod 5xx accumulated over 6h (the error-budget alarm) | warning |
ProdUnhandledExceptions |
≥3 app tag=http.error in 30m |
warning |
NotifierHeartbeatMissingProd |
no tag=heartbeat line from prod in 20m |
critical |
NotifierHeartbeatMissingBeta |
same, on beta | warning |
ProdWebContainerSilent |
thermograph_web logged nothing in 30m |
critical |
ProdDbContainerSilent |
thermograph_db logged nothing in 2h |
critical |
ProdFrontendContainerSilent |
thermograph_frontend logged nothing in 30m |
warning |
ProdWorkerContainerSilent |
thermograph_worker logged nothing in 2h |
warning |
AlertingWatchdog |
always — one Discord message per day | watchdog |
Every threshold was backtested against real Loki data; the working is written out
in the comments of rules-prod.yml, next to the rule it justifies. Read those
before changing a number.
AlertingWatchdog is the dead-man's switch and fires permanently by design. Its
value is its absence: nothing can report its own death, so if #ops-alerts has
been silent for more than a day, alerting is broken rather than the estate
healthy. Set isPaused: true on it to opt out of that guarantee.
Deploying an alerting change to vps1
Grafana already mounts ./grafana/provisioning read-only, so new files under
alerting/ need no compose change — but the first deploy does, because it
introduces DISCORD_ALERT_WEBHOOK_URL, and docker restart will not pick up a
new environment variable.
# run from the mono-repo root
VPS1="agent@75.119.132.91" # the monitoring host — NOT the beta environment,
# which now runs on vps2; don't repoint this at it.
SSH="ssh -i ~/.ssh/thermograph_agent_ed25519"
TS=$(date -u +%Y%m%dT%H%M%SZ)
# 1. put the secret in vps1's .env (once), then confirm it took:
$SSH $VPS1 "grep -q '^DISCORD_ALERT_WEBHOOK_URL=' /opt/observability/.env && echo present || echo MISSING"
# 2. back up the live compose file, stage the new files, move them into place:
$SSH $VPS1 "sudo cp -a /opt/observability/docker-compose.yml /opt/observability/docker-compose.yml.$TS \
&& rm -rf /tmp/obs-stage && mkdir -p /tmp/obs-stage/alerting"
scp -i ~/.ssh/thermograph_agent_ed25519 observability/docker-compose.yml $VPS1:/tmp/obs-stage/
scp -i ~/.ssh/thermograph_agent_ed25519 observability/grafana/provisioning/alerting/*.yml $VPS1:/tmp/obs-stage/alerting/
$SSH $VPS1 "sudo mkdir -p /opt/observability/grafana/provisioning/alerting \
&& sudo cp /tmp/obs-stage/docker-compose.yml /opt/observability/ \
&& sudo cp /tmp/obs-stage/alerting/*.yml /opt/observability/grafana/provisioning/alerting/"
# 3. recreate Grafana so it reads the new env var AND the new provisioning.
# `docker restart` is NOT enough here — it will not pick up a new env var.
$SSH $VPS1 "cd /opt/observability && docker compose up -d grafana"
Subsequent rule-only changes are just step 2 plus
sudo docker restart observability-grafana-1 — no compose needed, because no
new environment variable is involved.
Rollback: the provisioning files are additive. To back the whole thing out,
sudo rm -rf /opt/observability/grafana/provisioning/alerting, restore
docker-compose.yml.<timestamp>, and docker compose up -d grafana. Grafana
falls back to its default (email → <example@email.com>) root policy — i.e. no
alerting, which is where this started.
Alerting lives on vps1 only — vps2 (prod + beta) and dev only run Alloy
agents, not Grafana, so nothing in alerting/ ever ships to them, even though
dev happens to share a box with vps1's Grafana.
Verify alerting
# on vps1, after deploying and restarting Grafana:
GFP=$(grep '^GF_SECURITY_ADMIN_PASSWORD=' /opt/observability/.env | cut -d= -f2-)
WH=$(grep '^DISCORD_ALERT_WEBHOOK_URL=' /opt/observability/.env | cut -d= -f2-)
# 1. all 12 rules loaded and healthy (health should be "ok", never "error"):
curl -s -u admin:"$GFP" localhost:3000/api/prometheus/grafana/api/v1/rules \
| python3 -c 'import json,sys; [print(r["name"], r["state"], r["health"]) for g in json.load(sys.stdin)["data"]["groups"] for r in g["rules"]]'
# 2. the root policy points at Discord, NOT grafana-default-email:
curl -s -u admin:"$GFP" localhost:3000/api/v1/provisioning/policies
# 3. force a real message into #ops-alerts (does not persist anything):
curl -s -u admin:"$GFP" -H 'Content-Type: application/json' \
-X POST localhost:3000/api/alertmanager/grafana/config/api/v1/receivers/test \
-d '{"receivers":[{"name":"t","grafana_managed_receiver_configs":[{"name":"t","type":"discord","settings":{"url":"'"$WH"'"}}]}]}'
# -> {"receivers":[{... "status":"ok"}]} and a message in #ops-alerts.
The webhook URL is redacted ([REDACTED]) by
GET /api/v1/provisioning/contact-points, so you cannot confirm
interpolation by reading it back — the only proof is a message actually arriving
in #ops-alerts. A contact point holding the literal string
$DISCORD_ALERT_WEBHOOK_URL looks completely healthy from the API and pages
nobody.
The leftover default contact point
Grafana's built-in grafana-default-email → <example@email.com> receiver is
created by Grafana's default Alertmanager config, not by provisioning, and its
uid is the empty string. deleteContactPoints matches on uid, so provisioning
cannot remove it (DELETE /api/v1/provisioning/contact-points/ with an empty
uid returns 404 — verified).
Provisioning the notification policy already makes it inert: nothing routes there
any more, so it cannot receive anything. Actually deleting the row is a one-time
manual step, and only works after this config is live (Grafana refuses to
delete a receiver a policy still references). Either use the UI — Alerting →
Contact points → grafana-default-email → Delete — or:
# on vps1. Reads the running Alertmanager config, drops the one receiver,
# writes it back. Verified against Grafana 11.6.1 (returns 202).
GFP=$(grep '^GF_SECURITY_ADMIN_PASSWORD=' /opt/observability/.env | cut -d= -f2-)
AM=localhost:3000/api/alertmanager/grafana/config/api/v1/alerts
curl -s -u admin:"$GFP" $AM > /tmp/am.json
python3 -c "
import json; d=json.load(open('/tmp/am.json')); c=d['alertmanager_config']
c['receivers']=[r for r in c['receivers'] if r['name']!='grafana-default-email']
json.dump(d, open('/tmp/am2.json','w'))"
curl -s -u admin:"$GFP" -H 'Content-Type: application/json' -X POST --data @/tmp/am2.json $AM
rm -f /tmp/am.json /tmp/am2.json
This is cosmetic — leaving it costs nothing but a confusing row in the UI.
Notes / follow-ups
- Loki is mesh-only by design; only Grafana (with auth) is public.
- Alloy reads the Docker socket read-only to discover containers.
- Retention is 30 days on vps1's disk — bump
loki/config.ymlif you want more. - The app emits a
tag=heartbeatline for the subscription notifier every ~15m; the dashboard's "Notifier alive?" panel turns red if a node misses it. Extend the sameaudit.log_heartbeat()to any future background daemon.
Known gaps
- Alloy can silently stop tailing a container after Swarm replaces the task.
Observed on prod on 2026-07-24:
thermograph_workerwas1/1, healthy, and writing ~19 lines per 10 minutes to its own docker log, yet not one line had reached Loki since 04:43Z — a 13½-hour hole nobody could see, because nothing was watching.ProdWorkerContainerSilentnow catches exactly this. What localises it to Alloy rather than the app: prod'stag=heartbeatlines kept arriving in every 20-minute window throughout, and those come from a different Alloy source (loki.source.fileon/applogs) than the container stdout (loki.source.docker). One source went deaf, the other did not. The workaround issudo docker restart alloy-alloy-1on the affected node; the fix is probably an explicitrefresh_intervalondiscovery.dockerplus a look at whetherloki.source.dockerre-resolves targets. Not root-caused. - Some services are too quiet to alert on.
thermograph_daemon(23 log lines/24h),thermograph_autoscaler(1) andthermograph_autoscaler-lake(2) have a healthy floor indistinguishable from dead, andthermograph_lakeis bursty ETL with legitimate idle gaps. Giving each one anaudit.log_heartbeat()line would make all four alertable with the same pattern the notifier already uses. That is the single highest-value follow-up here. - Grafana cannot alert on its own death — that is what
AlertingWatchdogis for, but it is a manual dead-man's switch: it relies on somebody noticing that the daily message stopped. A real external watchdog (an uptime pinger hitting a Grafana endpoint from off-estate) would close this properly. - vps1 runs a
docker-compose.override.ymlthat is not in this repo, wiring Grafana's SMTP to vps2's Postfix. It should be mirrored into the tracked compose file or deleted; alerting no longer depends on it.