Function serve_ingestion 

pub async fn serve_ingestion(
    listen_addr: SocketAddr,
    lake: DataLakeConnection,
    auth_provider: Option<Arc<dyn AuthProvider>>,
    shutdown: impl Future<Output = ()> + Send + 'static,
    grace: Duration,
) -> Result<()>

Assemble and serve the HTTP ingestion endpoint.

Binds listen_addr, wires the ingestion routes + OTLP routes, applies the supplied auth_provider (or runs open when None), and shuts down gracefully when shutdown resolves.

Ingestion exposes no key-management HTTP surface of its own — keys for both ingestion_api_keys and analytics_api_keys are administered exclusively through analytics-web-srv’s own routes. Ingestion still validates incoming API keys via whichever auth_provider it was built with (including a DbApiKeyAuthProvider), it just does not expose a way to mint/list/revoke them.