Frank
06d3502a2b
ComfyUI's page described a compose service and a systemd unit that shelled out to `podman compose up`. It now documents the Quadlet, the keep-groups + udev mechanism (verified inside the running container: torch sees Radeon 8060S), the 9,146-restart incident that forced the move, and the trap that caused it — a stale container outlives the compose edit that should have replaced it. The observability page gains the audit result: four jobs read "down" and three of them always will, because they scrape HTML pages or a /metrics that does not exist. The page names each error, says plainly that none is an outage, and refuses the tempting fix (deleting the job makes an absent scrape look like a healthy one) in favour of the remedy it already recommended: a blackbox exporter in probe mode, and Gitea's metrics enabled or the job repointed.
137 lines
11 KiB
Markdown
137 lines
11 KiB
Markdown
---
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type: reference
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title: Observability on Dankclaw
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description: The Dankclaw observability stack — Prometheus, Grafana, Loki, Alloy and node-exporter: what runs, how it is deployed, how it is exposed, and what is still unconfigured.
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tags: [observability, prometheus, grafana, loki, alloy, node-exporter, quadlet, dankclaw]
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timestamp: 2026-09-11
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---
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# Observability
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The observability stack runs on Dankclaw: Prometheus for metrics, Loki for logs, Alloy as the shipper, Grafana for dashboards and node-exporter for host metrics. This is a small homelab — no Kubernetes.
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## Stack
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```mermaid
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graph LR
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S[Services] -->|/metrics| P[Prometheus]
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H[Host] -->|":9100"| P
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S -->|logs| A[Alloy]
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J[journald] --> A
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A --> L[Loki]
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P --> G[Grafana]
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L --> G
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```
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| Component | Role | Image | Published |
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|-----------|------|-------|-----------|
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| [[Prometheus]] | metrics collection | `prom/prometheus` | `127.0.0.1:9090` |
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| [[Grafana]] | dashboards | `grafana/grafana` | `127.0.0.1:3002` |
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| [[Loki]] | log storage & query | `franksdank/loki` (local build) | `127.0.0.1:3100` |
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| [[Alloy]] | log shipping | `franksdank/alloy` (local build) | `127.0.0.1:12345` |
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| [[Node-Exporter]] | host metrics | `prom/node-exporter` | `192.168.0.143:9100`, host netns |
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## Current state: installed, healthy, and mostly unconfigured
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Recorded 2026-09-11, on the day the stack moved to Quadlet units. Everything in the table above is deployed, healthy and boot-persistent. Almost nothing is wired up beyond the default install:
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- **Grafana has a datasource and one dashboard as of 2026-09-16; before that it had neither.** `shared/grafana/provisioning/` is installed to `/opt/grafana/provisioning` by the deployer and read by the container: the Prometheus datasource (`http://prometheus:9090`, fixed uid `prometheus`) and the **LLM fleet — capacity and reuse** dashboard (KV pool fill, queue depth, prefix-cache reuse, latency p95, throughput) covering both LLM endpoints. Verified through the API rather than by eye — the datasource answers `vllm:kv_cache_usage_perc` for `frank-medium`, and `GET /api/search?type=dash-db` returns uid `llm-fleet`. One trap worth knowing: a provisioned dashboard does **not** appear in the legacy `dashboard` table on this Grafana version (it lives in unified storage behind `dashboard.grafana.app`), so the API is the way to check. Still outstanding: no dashboards beyond this one, no Loki queries, and only datasources+dashboards are provisioning-as-code.
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- **Grafana's dashboard now also surfaces firing alerts.** The **Alerts firing (ALERTS)** panel graphs `ALERTS{alertstate="firing"}` for the LLM rules, because this stack has no other place where an alert becomes visible without opening Prometheus.
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- **Prometheus now evaluates rules; nothing delivers them (2026-09-16).** `shared/prometheus/rules/llm-fleet.yml` ships with the config (the deployer's `copy_prometheus_config` installs both — a rule file nothing loads evaluates nothing, and Prometheus reports no error for that) and holds six rules for the LLM fleet: pool saturation, request queueing, prefix-cache collapse, endpoint down, p95 latency, plus the `job:llm_prefix_cache_reuse:rate5m` recording rule the alert and the dashboard share. Verified with `promtool check rules` (SUCCESS, 6 rules) and `/api/v1/rules` (all six `health=ok`). **There is still no Alertmanager and no contact point anywhere**: a firing alert appears on Prometheus' `/alerts`, in the `ALERTS` metric and on the LLM fleet dashboard's alerts panel — and reaches a human only if one is looking.
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- **Loki is configured but unread.** Storage is filesystem with 30-day retention, `auth_enabled: false`, and the push path works; Grafana can now reach it in Explore, but no dashboard or alert consumes it.
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- **node-exporter runs its default collector set** — no collector tuning, no textfile collector for custom metrics.
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- **Alloy is the one configured piece.** It ships the host journal and podman container logs to Loki with `job` labels, and that pipeline is live.
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The honest summary: metrics and logs are collected and retained, one dashboard visualizes the LLM fleet, six rules evaluate over it, and **no rule reaches a person** — there is no Alertmanager and no contact point, so correlation stays manual and every signal has to be looked at.
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## Deployment
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Six units now, across two hosts. Dankclaw runs five (Prometheus, Grafana, Loki,
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Alloy, node-exporter) from `dankclaw/observability/quadlet/`; **Dankserver runs
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its own node-exporter** from `dankserver/observability/quadlet/`, added
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2026-09-16 after the same reboot argument took it down a second time — it had
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been a compose-only service, died `Exited (143)` at a reboot, and left
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Prometheus' `node-dankserver` job scraping nothing for a day and a half (its
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compose form also bound the wildcard address). The deployer installs from
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`"$TARGET/observability/quadlet"`, so each host owns its own units.
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The Dankclaw five left `dankclaw/compose.yaml` on 2026-09-11, after a reboot proved that compose-only containers do not come back on their own — the same gap that had already taken Caddy and Pi-hole down at earlier reboots, and the one that finally caught Dankserver's node-exporter. **What runs is now the unit; the compose file is the historical record.**
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```bash
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./scripts/deploy.sh dankclaw --service loki # or prometheus|grafana|alloy|node-exporter
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./scripts/deploy.sh dankserver --service node-exporter
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```
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`deploy_observability` in `scripts/deploy-remote.sh` installs the unit, restarts it and waits on its endpoint. Ordering lives in the units themselves (Grafana wants Prometheus, Alloy wants Loki), and `SERVICE_ORDER` in the planner puts each dependency first.
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Every unit carries a healthcheck, so a wedged process reads `unhealthy` in `podman ps` rather than merely `Up`. See [[Loki]] for the one unit that cannot declare it inline.
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## Exposure
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The rule is the same as for every other service: the only off-host path is a guarded vhost (`<name>.franksdank.cloud` → Anubis → Authentik embedded outpost). Two consequences are easy to get wrong:
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- **Prometheus, Grafana, Loki and Alloy publish on `127.0.0.1` only.** Caddy reaches them by container name over the `dankclaw_default` network, and the host-side homepage status timer probes loopback. Publishing on `0.0.0.0` — what the compose services did — put an unauthenticated metrics API (with the lifecycle endpoint enabled), dashboard, log store and log-ingest endpoint on every host interface, which is a bypass around the guard chain.
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- **node-exporter is the one deliberate LAN listener, and there are two of them now — one per host.** Prometheus runs in a container and cannot reach either host's loopback, so each unit binds exactly two addresses: loopback (`127.0.0.1:9100`) for host-local probes and its own LAN address (`192.168.0.143:9100` on Dankclaw, `192.168.0.235:9100` on Dankserver) for Prometheus. `ss -ltn` on Dankserver shows exactly those two listeners and no wildcard. Neither authenticates anything, so neither gets a vhost.
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## Scrape surface
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`shared/prometheus/prometheus.yml` is the source of truth (installed to `/opt/prometheus/config/` on every deploy). It scrapes:
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| Job | Target | Notes |
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|-----|--------|-------|
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| `prometheus` | `localhost:9090` | itself |
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| `node-dankclaw`, `node-dankserver` | `192.168.0.143:9100`, `192.168.0.235:9100` | one node-exporter per host |
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| `gitea` | `192.168.0.143:3000` | published LAN port (Gitea is on an isolated network) |
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| `grafana`, `loki` | `grafana:3000`, `loki:3100` | container names on `dankclaw_default` |
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| `comfyui` | `comfyui:8188` | UI probe, no native exporter |
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| `services` | `192.168.0.143:8081`, `:3005` | SearXNG, OpenWebUI up/down probes |
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| `frank-medium` | `192.168.0.235:7770` | vLLM on Dankserver — 418 `vllm:` series |
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| `frank-large` | `192.168.0.143:7770` | llama.cpp on Dankclaw — `llamacpp:` counters |
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The two LLM endpoints were added on 2026-09-16, after a night spent diagnosing
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frank-medium by hand. vLLM exports exactly what that diagnosis needed:
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`vllm:kv_cache_usage_perc` (how full the per-card pool is),
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`vllm:num_requests_waiting` (queue depth), the request-latency histograms, and
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the prefix-cache counters `vllm:prefix_cache_hits_total` /
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`vllm:prefix_cache_queries_total`, whose rates give the reuse rate that says
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whether a pinned conversation is being served warm or re-prefilled cold. What
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those numbers mean on this hardware is in [[frank-medium-radiance-mxfp4]].
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Both are scraped on their LAN addresses, never on the guarded vhosts:
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Prometheus cannot solve an Anubis challenge.
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For services without a native exporter, use the Prometheus **blackbox exporter** in probe mode to assert up/down and HTTP latency. The homepage status timer probes the same endpoints from the host.
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**Four jobs read "down" and three of them always will** (found 2026-09-16 while
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auditing why the target list was not green):
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| job | error | what it means |
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|-----|-------|---------------|
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| `comfyui` | `unsupported Content-Type "text/html"` | the service is **up** (this is what it says since ComfyUI was fixed — before that it read `connection refused`); Prometheus refuses to parse an HTML page as metrics, so this job cannot succeed as configured |
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| `services` (SearXNG, OpenWebUI) | `unsupported Content-Type "text/html; charset=utf-8"` | same defect: "blackbox-style probes" that scrape a page instead of metrics |
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| `gitea` | `HTTP status 404 Not Found` | `/metrics` does not exist on that Gitea (metrics disabled); the service itself is fine |
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None of these is an outage, and none should be silenced by deleting the job —
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an absent scrape and a healthy one look identical. The fix the repository
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already names is a **blackbox exporter** in probe mode for the page-only
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targets, and either enabling Gitea's metrics or pointing the job at the right
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path. The LLM alert rules (`LlmEndpointDown`) are scoped to `frank-*`, so these
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probes generate no false pages.
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## Log aggregation choice
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Loki + Alloy is the lightweight Grafana-native option for a two-server homelab:
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- Alloy reads container logs from the host (journald socket + container log files) and pushes them to Loki. It replaces Promtail, which reached end-of-life on 2026-03-02.
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- Loki stores compressed logs with labels; queries run in Grafana's Explore.
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- No Elasticsearch memory cost, no Kubernetes required.
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Alternatives considered and rejected: ELK (too heavy), Promtail (EOL), VictoriaLogs (newer, less documentation), plain `journald` (no centralized query).
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## See Also
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- [[Grafana]], [[Prometheus]], [[Loki]], [[Alloy]], [[Node-Exporter]] — the components
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- [[Dankclaw Stack]] — the rest of the host
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- [[Homepage]] — the user-facing status surface, including the five status cards
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- [[Deployment Flow]] — the verify-before-declared-deployed contract
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