ASGI lifespan crash

client_python version: testing on 0.15.0 but the offending code exists in the master branch as well.

I'm trying to use the prometheus ASGI handler with Hypercorns DispatcherMiddleware. It sends lifecycle events which are not properly handled:

def make_asgi_app(registry: CollectorRegistry = REGISTRY, disable_compression: bool = False) -> Callable:
    """Create a ASGI app which serves the metrics from a registry."""

    async def prometheus_app(scope, receive, send):
        assert scope.get("type") == "http"
        # Prepare parameters

assert scope.get("type") == "http" ensures any ASGI middleware sending lifecycle events will fail to start the prometheus asgi app.

make_asgi_app 関数と、ASGI scope の型が http であることを確認する assertion から始めます。Hypercorn の DispatcherMiddleware で Prometheus ASGI handler を使用し、そのライフサイクルイベントも含めて失敗を再現します。ライフサイクルイベントによって起動時にクラッシュせず、handler が引き続きメトリクスリクエストを処理できれば完了です。