spec(prometheus-direct-charting): add proposal + spec
Drop Grafana as chart middleman; query Prometheus directly via /api/v1/query_range. Rebrand GrafanaChartWidget -> PrometheusChartWidget, add gauge + mean widget kinds, remove Grafana surface, rewrite stale thin-dashboard rule in config.yaml. 27 acceptance requirements (SC-101..127).
This commit is contained in:
Developer
@@ -0,0 +1,131 @@
|
||||
# SDD Proposal: Prometheus Direct Charting (drop Grafana middleman)
|
||||
|
||||
**Change:** `prometheus-direct-charting`
|
||||
**Phase:** proposal
|
||||
**Date:** 2026-07-08
|
||||
|
||||
## 1. Problem / Why Now
|
||||
|
||||
Manage already does in-app charting — but indirectly. Today the only chart path is:
|
||||
|
||||
```
|
||||
GrafanaChartWidget (recharts) ← GrafanaWidgetSource._fetch_chart
|
||||
← POST {grafana}/api/ds/query (datasource.type = "prometheus", hardcoded)
|
||||
← Grafana proxies to Prometheus
|
||||
```
|
||||
|
||||
Two problems with this:
|
||||
|
||||
1. **Grafana is a pure middleman.** The backend already hardcodes `datasource.type: "prometheus"` in every chart query. Grafana adds a hop, an API key, a different response shape (`/api/ds/query` frames), and a normalization layer — all to reach a Prometheus instance Manage could query directly via `/api/v1/query_range`. The existing `PrometheusWidgetSource` already proves Manage can talk to Prom straight; it just only does *instant* queries today.
|
||||
2. **The project's documented rules are stale.** `openspec/config.yaml` says "Do NOT re-implement charting in-app" and "No recharts/d3 is in use." Both are already false in code: `recharts ^3.9.2` is declared and imported by `GrafanaChartWidget`. The config documents a reality the code left behind.
|
||||
|
||||
Meanwhile the operator wants two more metric visualizations Manage cannot currently render: a **gauge** and a **single value / mean-over-time** widget. Both belong naturally on the `prometheus` service, which today only exposes an instant-query numeric widget.
|
||||
|
||||
The clean answer is to stop routing charts through Grafana: query Prometheus directly, reuse the rendering infrastructure already written, add the two new modes, and remove the now-redundant Grafana surface.
|
||||
|
||||
## 2. Target Users and Situations
|
||||
|
||||
- **Primary users:** Homelab operators who want metric visualizations on the Manage dashboard without bouncing to Grafana for a quick glance.
|
||||
- **Workflow moments:**
|
||||
- Glance at the dashboard: see a trend line, a gauge, or a mean value for a key PromQL query.
|
||||
- Build a custom at-a-glance panel from any PromQL expression Manage can already evaluate.
|
||||
- Decommission the Grafana hop for charts (one fewer external dependency in the chart path, one fewer API key to rotate).
|
||||
- **Urgency:** Medium. Charts already work via Grafana today; this is a simplification plus two new widget modes, not an outage fix.
|
||||
|
||||
## 3. Product Outcome
|
||||
|
||||
After this change, an authenticated user can:
|
||||
|
||||
- Place a **Prometheus Chart** widget (line chart, multi-series) backed by a direct `/api/v1/query_range` call — same look as today's Grafana chart, no Grafana required.
|
||||
- Place a **Prometheus Gauge** widget rendering an instant PromQL scalar as a gauge.
|
||||
- Place a **Prometheus Mean** widget rendering a single value aggregated over a time window (e.g. `avg_over_time(...)`, or a query_range aggregate).
|
||||
- Manage the dashboard without any Grafana service configured: the Grafana service type, link widget, chart widget, and status checks are removed.
|
||||
|
||||
## 4. Scope Boundaries and Non-Goals
|
||||
|
||||
### In scope
|
||||
|
||||
- **Direct Prometheus range query path** — backend hits `/api/v1/query_range` and returns the existing `{series:[{label,points}]}` shape so the frontend renderer is reused unchanged.
|
||||
- **Shared series normalization** — extract the metric-label → readable-label logic currently inside `GrafanaWidgetSource._fetch_chart` into a reusable helper used by both the chart path and (where relevant) the new modes.
|
||||
- **Rebrand + rebind** — `GrafanaChartWidget` → `PrometheusChartWidget`, moved from the `grafana` service to the `prometheus` service as the `chart` widget kind.
|
||||
- **New `prometheus` widget kinds:** `gauge` and `mean` (semantics confirmed in the question round).
|
||||
- **Grafana removal** — delete `integrations/grafana.py`, `GrafanaWidgetSource`, `GrafanaLinkWidget`, `get_grafana_status`, the ObservabilityPage Grafana section, both registries' `grafana` entries, nav entries, and their tests.
|
||||
- **`config.yaml` rewrite** — replace the stale thin-dashboard / no-recharts wording with the reality: in-app charting via `recharts` is the sanctioned approach for Prometheus-backed series; Grafana is no longer referenced.
|
||||
- **Migration note** — CHANGELOG entry: existing Grafana service instances must be deleted and recreated as Prometheus services (true data migration is impossible; different URLs).
|
||||
|
||||
### Non-goals (explicitly out of scope)
|
||||
|
||||
- **A general chart-widget framework with pluggable data-source middlewares.** Chart rendering is reused; data sources are not abstracted into a swappable adapter registry. Two concrete sources (Prometheus range query, and later the service-storage harness) are wired directly where needed.
|
||||
- **Grafana datasource proxy for non-Prometheus sources** (Loki, InfluxDB, Postgres). If a real non-Prom need appears later, it is a separate change.
|
||||
- **Embedding Grafana panels as images/iframes.** Grafana is removed, not embedded.
|
||||
- **Editing PromQL in a rich editor** (autocomplete, metric explorer). Plain text input only, matching today's `prometheus_metric` widget.
|
||||
- **qBittorrent widgets and the service-storage harness.** Those are a separate change (`service-storage-harness`); only the qBit speed widget *depends on* this change's chart capability.
|
||||
- **Touching `prometheus_metric` (instant numeric widget).** It stays as-is; `mean` and `chart` are sibling kinds, not modes bolted onto it.
|
||||
- **Re-indexing or migrating existing widget instance rows automatically.** Existing `grafana` `chart` widgets are orphaned by the removal and must be recreated as `prometheus` `chart` widgets by the operator (documented in CHANGELOG).
|
||||
|
||||
## 5. High-Level Approach
|
||||
|
||||
### 5.1 Backend
|
||||
|
||||
1. **Prometheus range query** — extend `PrometheusWidgetSource` (or add a sibling code path) to handle `widget_kind == "chart"`:
|
||||
- `GET {base_url}/api/v1/query_range?query=...&start=...&end=...&step=...`
|
||||
- Parse Prom `{value:[ts, val]}` matrix into the existing `{series:[{label, points}]}` shape.
|
||||
2. **Shared normalization** — move the "metric labels → readable label" logic out of `GrafanaWidgetSource._fetch_chart` into `widgets/series.py` (or similar), so the Prom path and any future consumer reuse it.
|
||||
3. **New kinds wiring** — `gauge` and `mean` resolve in `PrometheusWidgetSource.fetch`:
|
||||
- `gauge`: instant query (`/api/v1/query`), return `{value, threshold?, ...}` for a gauge renderer.
|
||||
- `mean`: range query aggregated to a single value (either PromQL `avg_over_time` via instant query, or client-side mean over a query_range window). Semantics decided in the question round.
|
||||
4. **Integration update** — `integrations/prometheus.py` declares the three widget kinds (`metric`, `chart`, `gauge`, `mean`) with config schemas (`promql`, plus range params for `chart`/`mean`).
|
||||
5. **Grafana removal** — delete `integrations/grafana.py`, drop `grafana` from `SERVICE_ADAPTERS`, `SERVICE_DEFINITIONS`, remove `_fetch_chart` and the Grafana link logic. Remove `get_grafana_status` from `routers/monitoring.py` and the Grafana branch from `ObservabilityPage`.
|
||||
6. **`config.yaml` rewrite** — replace the stale charting rules with accurate wording.
|
||||
|
||||
### 5.2 Frontend
|
||||
|
||||
1. **Rebrand** — rename `GrafanaChartWidget.tsx` → `PrometheusChartWidget.tsx`; the recharts rendering (`LineChart`/`Line`/`XAxis`/`YAxis`/`Tooltip`/`mergeSeries`/`CHART_COLORS`) stays essentially unchanged.
|
||||
2. **Registry** — in `integrations/registry.ts`, move `chart` to the `prometheus` binding and add `gauge` + `mean` bindings; delete the entire `grafana` binding.
|
||||
3. **New components:**
|
||||
- `PrometheusGaugeWidget.tsx` — recharts `<RadialBarChart>` or a small SVG gauge; instant value.
|
||||
- `PrometheusMeanWidget.tsx` — single-value display (reuses `MetricCard`-style rendering) of the windowed mean.
|
||||
4. **Nav + ObservabilityPage** — remove Grafana nav entries and the Grafana status card.
|
||||
5. **Types** — `frontend/src/types/index.ts` drops Grafana status types; no new endpoint types (data still flows through `useWidgetData`).
|
||||
|
||||
### 5.3 Type contracts
|
||||
|
||||
- Backend: update `integrations/prometheus.py` widget-kind config models; remove Grafana models.
|
||||
- Frontend: remove `GrafanaStatus` type; widget payloads stay `{series}` / `{value}` shaped.
|
||||
|
||||
## 6. Success Criteria / Acceptance Criteria
|
||||
|
||||
1. A user can configure a Prometheus service and place `chart`, `gauge`, `mean`, and `metric` widgets without any Grafana service present.
|
||||
2. The `chart` widget renders multi-series line charts from `/api/v1/query_range` with the same look as the prior Grafana-backed chart.
|
||||
3. The `gauge` widget renders an instant PromQL scalar as a gauge.
|
||||
4. The `mean` widget renders a single value aggregated over the configured window.
|
||||
5. No `grafana` references remain in `backend/src` or `frontend/src` (grep clean).
|
||||
6. `openspec/config.yaml` no longer claims "no recharts" or "do not chart in-app"; its wording matches the implementation.
|
||||
7. Existing `pytest`, `npm run build`, and `npm run lint` stay green; Grafana tests are removed, Prom chart/gauge/mean tests are added.
|
||||
8. CHANGELOG documents the migration (delete Grafana services, recreate as Prometheus).
|
||||
|
||||
## 7. Risks and Mitigations
|
||||
|
||||
| Risk | Mitigation |
|
||||
|------|------------|
|
||||
| **Response-shape regression.** Prom `/api/v1/query_range` matrix differs from Grafana `/api/ds/query` frames. | Extract normalization into a shared helper; add a backend test that feeds a sample Prom range response and asserts the `{series}` shape the frontend already consumes. |
|
||||
| **Orphaned configured widgets.** Existing `grafana/chart` widget rows break at render. | Acceptable + documented in CHANGELOG; the widget resolves to "unknown widget" gracefully (existing `WidgetInstance` error path). No silent data corruption. |
|
||||
| **Gauge rendering complexity.** recharts gauges can be fiddly. | Constrain gauge to a single scalar + optional thresholds; if recharts gauge proves heavy, fall back to a ~50-line SVG gauge (contained, no new dep). |
|
||||
| **Scope creep into a generic chart framework.** Tempting to abstract data sources. | Non-goal enforced: two direct wirings, no adapter registry. |
|
||||
| **Stale docs/tests lingering.** | "No grafana references" acceptance criterion (grep) catches leftovers. |
|
||||
| **Review budget (>400 lines).** | Slice into chained PRs (e.g. Slice 1: Prom range query + rebrand chart; Slice 2: gauge + mean; Slice 3: Grafana removal + config rewrite). Each slice leaves build/lint/test green. |
|
||||
| **DataGrid migration (config rule callout).** | Not applicable — no DataGrid work here. The key technical risk is the response-shape regression above. |
|
||||
|
||||
## 8. Open Questions (for the proposal question round)
|
||||
|
||||
- **Q1 — `mean` semantics.** Default: client-side mean over a `query_range` window (e.g. last 1h, step 30s → average all returned values). Alternative: require the user to write `avg_over_time(...)` in the PromQL and just run an instant query. Which UX do you want?
|
||||
- **Q2 — `gauge` thresholds.** Default: green/amber/red bands at user-configured thresholds (e.g. 70%/90%). Alternative: single color, no bands (simplest).
|
||||
- **Q3 — Chart time window config.** Default: expose `from`/`to`/`step` (or a simpler "window" preset like 1h/6h/24h). Confirm the granularity users can configure.
|
||||
- **Q4 — Multi-series on `mean`/`gauge`.** Default: single series only (one scalar). Confirm we do not try to render multi-series gauges.
|
||||
|
||||
## 9. Future Phases
|
||||
|
||||
1. **Service-storage harness integration** — the qBittorrent speed widget (separate `service-storage-harness` change) reuses this change's chart rendering with an in-service data source wired directly.
|
||||
2. **Rich PromQL editing** — metric explorer / autocomplete.
|
||||
3. **Non-Prom datasources** — only if a concrete need (Loki logs in-app) appears.
|
||||
4. **Threshold-based alerting from chart widgets** — surface bands/lines from Alertmanager rules.
|
||||
@@ -0,0 +1,152 @@
|
||||
# SDD Spec: Prometheus Direct Charting (drop Grafana middleman)
|
||||
|
||||
**Change:** `prometheus-direct-charting`
|
||||
**Phase:** spec
|
||||
**Date:** 2026-07-08
|
||||
|
||||
This spec defines the acceptance requirements for the change. Each requirement is testable. Requirements derived from `proposal.md` §6 (success criteria) and the resolved §8 question round.
|
||||
|
||||
## Requirement categories
|
||||
|
||||
1. Direct Prometheus range query path
|
||||
2. Prometheus chart widget (rebrand + rebind)
|
||||
3. Prometheus gauge widget
|
||||
4. Prometheus mean widget
|
||||
5. Grafana removal
|
||||
6. Configuration documentation accuracy
|
||||
7. Test and build greenness
|
||||
8. Migration guidance
|
||||
|
||||
---
|
||||
|
||||
## 1. Direct Prometheus range query path
|
||||
|
||||
### SC-101 — Prometheus range query returns the existing series shape
|
||||
|
||||
When a `prometheus` widget of kind `chart` is fetched, the backend MUST query `{base_url}/api/v1/query_range` with `query`, `start`, `end`, and `step` derived from the widget config, and return a payload of shape `{ "series": [{ "label": str, "points": [{ "t": int, "v": float|null }] }] }` — the exact shape the frontend chart renderer already consumes.
|
||||
|
||||
### SC-102 — Series label normalization is shared and Prometheus-native
|
||||
|
||||
The metric-label → readable-label normalization MUST live in a single shared helper (not duplicated in a Grafana path) and MUST produce meaningful labels for Prometheus matrix results, including deduplicating repeated labels via a `label (n)` suffix.
|
||||
|
||||
### SC-103 — Range query errors degrade gracefully
|
||||
|
||||
A Prometheus timeout, connection error, or non-2xx response MUST cause the widget data fetch to return `{ "error": str }` (not raise), so the frontend renders the standard per-widget error state and the rest of the dashboard remains functional.
|
||||
|
||||
### SC-104 — Step is derived from the window preset
|
||||
|
||||
Given a window preset (1h / 6h / 24h / 7d), the backend MUST derive a `step` that yields a reasonable number of points (target ~100–300 points). Users do not configure `step` directly.
|
||||
|
||||
## 2. Prometheus chart widget (rebrand + rebind)
|
||||
|
||||
### SC-105 — Chart widget moves from grafana to prometheus
|
||||
|
||||
A widget kind named `chart` MUST be bound to the `prometheus` service type in both the backend registry and the frontend `SERVICE_REGISTRY`. The `grafana` service type MUST NOT offer a `chart` kind.
|
||||
|
||||
### SC-106 — Chart renderer is reused unchanged
|
||||
|
||||
The recharts rendering (line chart, multi-series, axes, tooltip, `mergeSeries`, color tokens) MUST be preserved in the rebranded `PrometheusChartWidget`. The rename is structural; the rendering code is not rewritten.
|
||||
|
||||
### SC-107 — Chart supports multiple series
|
||||
|
||||
The `chart` widget MUST render all series returned by the range query, each as its own line with a distinct color. There is no single-series restriction on `chart`.
|
||||
|
||||
### SC-108 — Chart window is a preset
|
||||
|
||||
The `chart` widget config MUST expose the time window as a preset selector (`1h`, `6h`, `24h`, `7d`), not raw `from`/`to`/`step` fields. The preset is stored in widget config and resolved to `start`/`end` server-side.
|
||||
|
||||
## 3. Prometheus gauge widget
|
||||
|
||||
### SC-109 — Gauge renders an instant scalar
|
||||
|
||||
A widget kind named `gauge` MUST be bound to the `prometheus` service. Its data fetch MUST run an instant PromQL query (`/api/v1/query`) and return the scalar result for rendering as a gauge.
|
||||
|
||||
### SC-110 — Gauge supports configurable threshold bands
|
||||
|
||||
The `gauge` widget config MUST accept optional threshold values (e.g. `warn_at`, `crit_at`) and the renderer MUST display green / amber / red bands accordingly. When thresholds are omitted, the gauge renders with a single neutral color and no bands.
|
||||
|
||||
### SC-111 — Gauge is scalar-only
|
||||
|
||||
The `gauge` widget MUST render exactly one scalar value. If the instant query returns multiple series, the adapter MUST return `{ "error": str }` (not silently pick one), directing the user to refine the PromQL.
|
||||
|
||||
## 4. Prometheus mean widget
|
||||
|
||||
### SC-112 — Mean computes client-side over a window
|
||||
|
||||
A widget kind named `mean` MUST be bound to the `prometheus` service. Its data fetch MUST run a range query over the configured window preset and return the arithmetic mean of all non-null point values as a single scalar.
|
||||
|
||||
### SC-113 — Mean uses plain PromQL + window preset
|
||||
|
||||
The `mean` widget config MUST accept a plain PromQL expression (no requirement to wrap in `avg_over_time`) plus a window preset. Users do not write range-vector functions.
|
||||
|
||||
### SC-114 — Mean is scalar-only
|
||||
|
||||
The `mean` widget MUST render exactly one scalar value. If the range query returns multiple series, the adapter MUST return `{ "error": str }` (not silently aggregate across series).
|
||||
|
||||
## 5. Grafana removal
|
||||
|
||||
### SC-115 — No grafana references in backend source
|
||||
|
||||
After the change, `grep -ri grafana backend/src --include='*.py'` MUST return no matches (excluding comments/changelog that are explicitly about the removal, if any are retained — but ideally zero).
|
||||
|
||||
### SC-116 — No grafana references in frontend source
|
||||
|
||||
After the change, `grep -ri grafana frontend/src` MUST return no matches.
|
||||
|
||||
### SC-117 — Grafana service type is gone from registries
|
||||
|
||||
Neither the backend `SERVICE_DEFINITIONS` / `SERVICE_ADAPTERS` nor the frontend `SERVICE_REGISTRY` / `BUILTIN_WIDGETS` MUST contain a `grafana` entry. The `integrations/grafana.py` file MUST be deleted.
|
||||
|
||||
### SC-118 — Grafana status checks are removed
|
||||
|
||||
The `get_grafana_status` endpoint and its frontend hook (`useGrafanaStatus`) MUST be removed. The ObservabilityPage MUST NOT render a Grafana status section.
|
||||
|
||||
### SC-119 — Grafana widget instances degrade gracefully
|
||||
|
||||
An existing persisted widget row referencing a `grafana` service MUST NOT crash the dashboard. It resolves to the existing "unknown widget" error state and surfaces a clear message; the operator can then delete it.
|
||||
|
||||
### SC-120 — Grafana tests are removed
|
||||
|
||||
All Grafana-specific tests (backend and frontend) MUST be deleted; no test references grafana.
|
||||
|
||||
## 6. Configuration documentation accuracy
|
||||
|
||||
### SC-121 — config.yaml matches implementation
|
||||
|
||||
`openspec/config.yaml` MUST NOT contain the stale claims "Do NOT re-implement charting in-app" or "No recharts/d3 is in use." It MUST reflect that in-app charting via `recharts` is the sanctioned approach for Prometheus-backed series, and MUST NOT reference Grafana as a chart path.
|
||||
|
||||
### SC-122 — CHANGELOG documents the migration
|
||||
|
||||
`CHANGELOG.md` MUST include an entry instructing operators to delete existing Grafana service instances and recreate them as Prometheus services, noting that configured `grafana/chart` widgets must be recreated as `prometheus/chart` widgets.
|
||||
|
||||
## 7. Test and build greenness
|
||||
|
||||
### SC-123 — Backend tests pass
|
||||
|
||||
`pytest` run from `backend/` MUST pass, including new tests covering: Prom range query → `{series}` normalization, gauge scalar-only enforcement, mean client-side aggregation, and the shared label helper.
|
||||
|
||||
### SC-124 — Frontend typechecks, builds, and lints
|
||||
|
||||
`npm run build` (which runs `tsc -b` + `vite build`) and `npm run lint` from `frontend/` MUST pass.
|
||||
|
||||
### SC-125 — New widget kinds have tests
|
||||
|
||||
`PrometheusChartWidget`, `PrometheusGaugeWidget`, and `PrometheusMeanWidget` MUST each have a frontend test covering at least: loading state, error state, and a rendered data case.
|
||||
|
||||
## 8. Migration guidance
|
||||
|
||||
### SC-126 — No silent data migration
|
||||
|
||||
The change MUST NOT attempt to auto-migrate existing `grafana` service rows into `prometheus` rows (URLs differ; true migration is impossible). Migration is operator-driven per the CHANGELOG note.
|
||||
|
||||
### SC-127 — Non-blocking on the service-storage-harness change
|
||||
|
||||
This change MUST NOT depend on the `service-storage-harness` change. It is independently buildable, testable, and deployable. (The reverse dependency holds: the qBit speed widget depends on this change's chart capability.)
|
||||
|
||||
---
|
||||
|
||||
## Notes for downstream phases
|
||||
|
||||
- **Design (next phase)** should specify: the exact `step`-derivation function for window presets (SC-104), the shared normalization helper's location and signature (SC-102), and whether the gauge renderer uses recharts `RadialBarChart` or a contained SVG (SC-110).
|
||||
- **Tasks** should slice into chained PRs ≤400 lines per `config.yaml` rules: e.g. (1) Prom range path + chart rebrand, (2) gauge + mean, (3) Grafana removal + config rewrite + CHANGELOG.
|
||||
- The **review-budget guard** applies: if total changed lines exceed ~400, the chained-PR strategy from the `tasks` phase is mandatory.
|
||||
Reference in New Issue
Block a user