Gabriel Radureau
f2771bc704
Closes ADR-0023 hot-reload Phase 3 (telemetry sampler). Last sub-phase of the 3-PR sequence: 3.1 = ReconfigureTracerProvider in pkg/telemetry (PR #45), 3.2 = sampler callback plumbing in pkg/config (in main via PR #47 race-merge — see Q-038 in mistral-quirks.md), 3.3 = wire it in pkg/server.Run (this PR). Implementation: - Capture telemetrySetup pointer (was a local) so it outlives initial setup and the sampler callback can mutate it. - After WatchAndApply registration, register a callback that: 1. Mutates SamplerType/SamplerRatio on the captured Setup 2. Calls ReconfigureTracerProvider (which builds the new TP, swaps the global, drains the old) 3. Updates s.tracerProvider so graceful shutdown still drains the correct provider. - Callback only registered if telemetrySetup != nil (telemetry was successfully initialized at startup; hot-reloading telemetry-on is out of scope per ADR-0023). ADR-0023 status updated: Phase 1+2+3 Implemented. api.v2_enabled remains explicitly deferred (router refactor needed; separate ADR). Race detector clean on touched packages. Full BDD suite green.
dance-lessons-coach
Go web service demonstrating idiomatic package structure, versioned JSON API, and production-ready features.
Features
- Versioned JSON API (
/api/v1,/api/v2) - Chi router with graceful shutdown
- Zerolog structured logging (console and JSON modes)
- Viper configuration (file + env vars)
- Readiness endpoint for Kubernetes / service mesh
- OpenTelemetry / Jaeger distributed tracing
- OpenAPI / Swagger UI (embedded in binary)
- PostgreSQL user service with JWT auth
- BDD + unit tests
Quick Start
git clone https://gitea.arcodange.lab/arcodange/dance-lessons-coach.git
cd dance-lessons-coach
./scripts/build.sh # produces ./bin/server and ./bin/greet
./scripts/start-server.sh start
curl http://localhost:8080/api/health
curl http://localhost:8080/api/v1/greet/Alice
Stop: ./scripts/start-server.sh stop
Greet CLI
go run ./cmd/greet # Hello world!
go run ./cmd/greet Alice # Hello Alice!
Configuration
All options are available via config.yaml or DLC_* environment variables.
| Env var | Default | Description |
|---|---|---|
DLC_SERVER_PORT |
8080 |
Listening port |
DLC_SERVER_HOST |
0.0.0.0 |
Bind address |
DLC_LOGGING_JSON |
false |
JSON log format |
DLC_LOGGING_OUTPUT |
stderr | Log file path |
DLC_SHUTDOWN_TIMEOUT |
30s |
Graceful shutdown window |
DLC_API_V2_ENABLED |
false |
Enable /api/v2 routes |
DLC_CONFIG_FILE |
./config.yaml |
Override config path |
See config.example.yaml for a full template.
API
| Method | Path | Description |
|---|---|---|
| GET | /api/health |
Liveness check |
| GET | /api/ready |
Readiness check (503 during shutdown) |
| GET | /api/version |
Version info (?format=plain|full|json) |
| GET | /api/v1/greet/ |
Default greeting |
| GET | /api/v1/greet/{name} |
Named greeting |
| POST | /api/v2/greet |
V2 greeting with validation |
| GET | /swagger/ |
Swagger UI |
Testing
go test ./... # unit + integration tests
./scripts/test-graceful-shutdown.sh # lifecycle + JSON logging validation
./scripts/test-opentelemetry.sh # tracing end-to-end
Gitea Client
AI agent helper script at .vibe/skills/gitea-client/scripts/gitea-client.sh.
Auth setup:
echo "your_token" > ~/.gitea_token
chmod 600 ~/.gitea_token
export GITEA_API_TOKEN_FILE="$HOME/.gitea_token"
Get a token at https://gitea.arcodange.lab → Profile → Settings → Applications.
Architecture
Key decisions are documented in adr/. See AGENTS.md for the full development reference (commands, config, ADR index, commit conventions).
License
MIT