Grpc

Detection

curl host:port
curl: (1) Received HTTP/0.9 when not allowed

curl -v --http2-prior-knowledge host:port
...
< HTTP/2 415
< content-type: application/grpc
< grpc-status: 3
< grpc-message: invalid gRPC request content-type ""

grpc reflection

grpcurl -plaintext <ip:port> list