## What & why S-16c, the last of the S-16 (#17) split, on top of the backplane (#122) and distributed tracing (#123). The five .NET services now expose OpenTelemetry **metrics** in Prometheus format at `/metrics`; Prometheus scrapes each (one job per service); and Grafana ships a pre-built **Request path — golden signals** dashboard (traffic / errors / latency / saturation), split by service. Closes #124 ### How - Each service adds `.WithMetrics(AddAspNetCoreInstrumentation + AddHttpClientInstrumentation + AddMeter("System.Runtime") + AddPrometheusExporter)` and maps `/metrics`. Same shape as the S-16b tracing wiring already in these `Program.cs` files. - `infra/observability/prometheus/prometheus.yml`: one scrape job per service (`acl`, `domain`, `bff`, `event-subscriber`, `projection-api`), reached by compose service name. - `infra/observability/grafana/provisioning/dashboards/`: dashboard provider + `golden-signals.json` (baked into the Grafana image by the existing `COPY provisioning/`). - `verify-metrics` (new CI verify-stack step + Makefile target): generates BFF traffic and asserts Prometheus scraped the golden-signal metric from every service. Mirrors `verify-tracing`. ### Dependency (CLAUDE.md §13/§14) Adds `OpenTelemetry.Exporter.Prometheus.AspNetCore` `1.17.0-beta.1` (matched to the `1.17.0` core already in use). It gives the OTel-native `/metrics` pull endpoint; replacing it would mean hand-rolling Prometheus exposition over a `MeterListener`; the risk is that it is a **prerelease** package (the whole OTel .NET Prometheus line is `-beta`) — pinned, wired only in `Program.cs`, and gated by `verify-metrics`. Recorded in **ADR-0024**. ## Definition of Done - [x] Linked Gitea issue (#124). - [x] Failing test committed before the implementation (`test(bff): /metrics exposes http-server request duration`). - [x] Implementation makes the test pass. - [ ] CI green — pending Gitea Actions run. - [x] `docker compose up` reaches green health within 3 min (backplane images unchanged in shape; not on the health gate, ADR-0023). - [x] Docs updated — demo-script S-16c entry. - [x] ADR added — ADR-0024. - [x] Demo note in `docs/demo-script.md`. ## Notes for reviewers - `/health` polls are counted as traffic (metrics aren't path-filtered, unlike traces). Fine for a demo dashboard and honest — real load stacks on top. - `projection-api` has no Stryker config (unchanged); the four mutated services carry the metrics wiring in `Program.cs`, same as the merged S-16b tracing code. - Metric names verified against a live service: `http_server_request_duration_seconds{,_bucket,_count}`, label `http_response_status_code`, `dotnet_process_cpu_time_seconds_total`. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Reviewed-on: #129
28 lines
854 B
YAML
28 lines
854 B
YAML
# Prometheus scrape config (S-16c, ADR-0023). Each .NET service exposes OTel metrics
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# at /metrics (Prometheus text format); one scrape job per service, so the service is
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# identified by the `job` label in the golden-signal dashboard. Targets are reached by
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# compose service name on the shared `cg` network (internal port 8080).
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global:
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scrape_interval: 15s
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scrape_configs:
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- job_name: prometheus
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static_configs:
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- targets: ['localhost:9090']
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- job_name: acl
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static_configs:
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- targets: ['acl:8080']
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- job_name: domain
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static_configs:
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- targets: ['domain:8080']
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- job_name: bff
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static_configs:
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- targets: ['bff:8080']
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- job_name: event-subscriber
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static_configs:
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- targets: ['event-subscriber:8080']
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- job_name: projection-api
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static_configs:
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- targets: ['projection-api:8080']
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