I build an experimental Bitcoin Core Prometheus metrics exporter based on the eBPF and USDT tracepoints I add in PR #22006 (https://github.com/bitcoin/bitcoin/pull/22006).
https://github.com/0xB10C/bitcoind-observer
Grafana demo available on https://bitcoind.observer
While limited by the three trancepoints added in #22006, it is already showing real time P2P message count and traffic per message type.
https://bitcoind.observer/d/Z3_pFfZnz/p2p-network-traffic?refresh=30s&var-msg_types=All