D-Net

prometheus-client==0.5.0

import time

from prometheus_client import Counter, Gauge, Histogram

from starlette.middleware.base import BaseHTTPMiddleware, RequestResponseEndpoint

from starlette.requests import Request

from starlette.responses import Response

REQUESTS = Counter("starlette_requests_total", "Total count of requests by method and path.", ["method", "path"])

RESPONSES = Counter(

    "scholexplorerAPI_responses_total",

    "Total count of responses by method, path and status codes.",

    ["method", "path", "status_code"],

)

REQUESTS_PROCESSING_TIME = Histogram(

    "scholexplorerAPI_requests_processing_time_seconds",

    "Histogram of requests processing time by path (in seconds)",

    ["method", "path"],

)

EXCEPTIONS = Counter(

    "scholexplorerAPI_exceptions_total",

    "Histogram of exceptions raised by path and exception type",

    ["method", "path", "exception_type"],

)

REQUESTS_IN_PROGRESS = Gauge(

    "scholexplorerAPI_requests_in_progress",

    "Gauge of requests by method and path currently being processed",

    ["method", "path"],

)

class PrometheusMiddleware(BaseHTTPMiddleware):

    async def dispatch(self, request: Request, call_next: RequestResponseEndpoint) -> Response:

        method = request.method

        path = request.url.path

        REQUESTS_IN_PROGRESS.labels(method=method, path=path).inc()

        REQUESTS.labels(method=method, path=path).inc()

        try:

            before_time = time.time()

            response = await call_next(request)

            after_time = time.time()

        except Exception as e:

            EXCEPTIONS.labels(method=method, path=path, exception_type=type(e).__name__).inc()

            raise e from None

        else:

            REQUESTS_PROCESSING_TIME.labels(method=method, path=path).observe(after_time - before_time)

            RESPONSES.labels(method=method, path=path, status_code=response.status_code).inc()

        finally:

            REQUESTS_IN_PROGRESS.labels(method=method, path=path).dec()

        return response

import os

from prometheus_client import CONTENT_TYPE_LATEST, REGISTRY, CollectorRegistry, generate_latest

from prometheus_client.multiprocess import MultiProcessCollector

from starlette.requests import Request

from starlette.responses import Response

def metrics(request: Request) -> Response:

    if "prometheus_multiproc_dir" in os.environ:

        registry = CollectorRegistry()

        MultiProcessCollector(registry)

    else:

        registry = REGISTRY

    return Response(generate_latest(registry), media_type=CONTENT_TYPE_LATEST)

from eu.dnetlib.metrics_utils import metrics 

from eu.dnetlib.metricsMiddleWare import PrometheusMiddleware

app.add_middleware(PrometheusMiddleware)

app.add_route("/metrics/", metrics)