P1 infra: expose queue/ffmpeg/upload/vod metrics

[SlavaKuntsov]

Phase / Priority / Area

Phase 14 · Priority P1 · Area infra

Зависимости

Blocked by: #11

Scope

services/gateway, services/metadata, services/upload, services/transcoder/app/consumer.py

Goal

4 метрики из docs/PLAN.md:237.

Acceptance Criteria

• rabbitmq_queue_depth, ffmpeg_duration_seconds (histogram), upload_bytes (counter), vod_cache_hit (counter) в Prometheus + Grafana dashboard

Проверки

curl :9090/api/v1/query?query=ffmpeg_duration_seconds, загрузка 1 видео → метрика растет

Out of scope

JSON логи (#14)

[SlavaKuntsov]

Pull request opened

#39 — will auto-close via Closes #13 on merge.

Verification

• make lint-go — 0 issues
• make lint-py — success
• make lint-front — ok
• make test-go/test-py — pass
• make up --build -d — all Healthy (prometheus, loki, grafana)
• make e2e — PASS
• curl -H X-Request-ID:test123 → logs contain trace_id; Loki query {service="gateway"} |= "test123" — success

Remaining risks

• Loki allow_structured_metadata false (v11), Promtail docker.sock, rabbitmq_queue_depth Gauge 0 — см. PR Risks