Changes committed

docengine/app/middleware/metrics.py

@@ -0,0 +1,29 @@
+from __future__ import annotations
+
+from fastapi import FastAPI
+from prometheus_fastapi_instrumentator import Instrumentator
+
+from app.core.config import settings
+
+
+def setup_metrics(app: FastAPI) -> None:
+    """Configure Prometheus metrics instrumentation."""
+    if not settings.prometheus_enabled:
+        return
+
+    instrumentator = Instrumentator(
+        should_group_status_codes=True,
+        should_ignore_untemplated=True,
+        should_respect_env_var=False,
+        excluded_handlers=["/metrics", "/api/v1/health", "/docs", "/openapi.json"],
+        env_var_name="PROMETHEUS_ENABLED",
+        inprogress_name="docengine_inprogress_requests",
+        inprogress_labels=True,
+    )
+
+    instrumentator.instrument(app).expose(
+        app,
+        endpoint="/metrics",
+        include_in_schema=False,
+        should_gzip=True,
+    )