server: add prometheus instrumentation

server/reflector/app.py

@@ -6,8 +6,10 @@ from fastapi import FastAPI
 from fastapi.middleware.cors import CORSMiddleware
 from fastapi.routing import APIRoute
 from fastapi_pagination import add_pagination
+from prometheus_fastapi_instrumentator import Instrumentator
 from reflector.events import subscribers_shutdown, subscribers_startup
 from reflector.logger import logger
+from reflector.metrics import metrics_init
 from reflector.settings import settings
 from reflector.views.rtc_offer import router as rtc_offer_router
 from reflector.views.transcripts import router as transcripts_router
@@ -23,10 +25,10 @@ except ImportError:
 @asynccontextmanager
 async def lifespan(app: FastAPI):
     for func in subscribers_startup:
-        await func()
+        await func(app)
     yield
     for func in subscribers_shutdown:
-        await func()
+        await func(app)
 
 
 # use sentry if available
@@ -49,6 +51,12 @@ app.add_middleware(
     allow_headers=["*"],
 )
 
+# metrics
+instrumentator = Instrumentator(
+    excluded_handlers=["/docs", "/metrics"],
+).instrument(app)
+metrics_init(app, instrumentator)
+
 # register views
 app.include_router(rtc_offer_router)
 app.include_router(transcripts_router, prefix="/v1")