Does stream module have support to negotiate ALPN when terminating TLS?

[sojuro]

Is there support for forwarding to backends when clients are sending ALPN? I
would like to use the stream module if possible. The following nginx config
works successfully with a Go client but not with the Ruby client. This is
similar to the problem with AWS ELB
https://github.com/grpc/grpc/issues/18710 


stream {
	upstream stream_backend_1 {
		server mygrpcservice:8080;
	}
	server {
		listen 443 ssl;
		proxy_pass            stream_backend_1;
		ssl_certificate       /etc/ssl/test_cert.pem;
		ssl_certificate_key   /etc/ssl/test_key.pem;
		ssl_preread 		  on;
	}
}

With preread on and nginx-debug I got the following in the logs and so the
client is sending ALPN data 
2019/12/15 03:21:12 [debug] 12#12: *1 ssl preread: ALPN protocols
"grpc-exp"
2019/12/15 03:21:12 [debug] 12#12: *1 ssl preread: ALPN protocols
"grpc-exp,h2"

but the Handshake fails in the grpc library because Server does not set the
negotiated ALPN??
D1214 23:00:44.714269000 123145438679040 security_handshaker.cc:186]  
Security handshake failed:
{"created":"@1576393244.714255000","description":"Cannot check peer: missing
selected ALPN
property.","file":"src/core/lib/security/security_connector/ssl_utils.cc","file_line":118}


Also fails with openssl 

$ openssl s_client -connect test00.net:443 -alpn h2 | grep alpn
verify return:1
No ALPN negotiated

-s

Posted at Nginx Forum: https://forum.nginx.org/read.php?2,286473,286473#msg-286473