id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	uname	nginx_version
1558	nginx does not pass metadata to grpc server	Jürgen De Commer		"nginx is configured with the most basic grpc proxy config. This is the only configuration in use:

{{{
http {
    log_format  main  '$remote_addr - $remote_user [$time_local] ""$request"" '
                      '$status $body_bytes_sent ""$http_referer"" '
                      '""$http_user_agent"" ""$http_x_forwarded_for""';

    access_log  logs/access.log  main;

    server {
        listen 9080 http2;
        location / {
            grpc_pass localhost:5000;
        }
    }
}

}}}

I have a grpc client that adds metadata to its outgoing context:

{{{
func testDataInterceptor(ctx context.Context, method string, req, reply interface{}, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
	traceID := uuid.New().String()
	ctx = metadata.AppendToOutgoingContext(ctx,
		""trace.id"", traceID,
		""trace.application"", ""test-client"",
		""auth.jwt"", xxxxx)

	return invoker(ctx, method, req, reply, cc, opts...)
}
}}}

On the server side, this metadata is logged by an interceptor.

{{{
	md, ok := metadata.FromIncomingContext(ctx)
	if !ok {
		log.Printf(""Attempt to execute %s without providing metadata"", info.FullMethod)
		return nil, status.Error(codes.Unauthenticated, ""Expected metadata but it was not present in the context"")
	}
	log.Println(""Context metadata"", md)
}}}

If the client is communicating directly with the server, the server has access to the metadata, producing following log:
{{{
2018/05/22 16:56:36 map[:authority:[localhost:5000] content-type:[application/grpc] user-agent:[grpc-go/1.12.0] trace.id:[7f0d8e18-654d-4b75-bae5-0e3f4ea33058] trace.application:[test-client] auth.jwt:[xxxxxxxx]]
}}}

If the client is communicating with nginx, then this information is no longer present when the request reaches the grpc server:

{{{
2018/05/22 16:57:10 Context metadata map[:authority:[localhost:5000] content-type:[application/grpc] user-agent:[grpc-go/1.12.0]]
}}}

Same behaviour on:


{{{
vagrant@scaler-1:~$ uname -a
Linux scaler-1 4.4.0-31-generic #50~14.04.1-Ubuntu SMP Wed Jul 13 01:07:32 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
vagrant@scaler-1:~$ nginx -V
nginx version: nginx/1.14.0
built by gcc 4.8.4 (Ubuntu 4.8.4-2ubuntu1~14.04.4)
built with OpenSSL 1.0.1f 6 Jan 2014
TLS SNI support enabled
configure arguments: --prefix=/etc/nginx --sbin-path=/usr/sbin/nginx --modules-path=/usr/lib/nginx/modules --conf-path=/etc/nginx/nginx.conf --error-log-path=/var/log/nginx/error.log --http-log-path=/var/log/nginx/access.log --pid-path=/var/run/nginx.pid --lock-path=/var/run/nginx.lock --http-client-body-temp-path=/var/cache/nginx/client_temp --http-proxy-temp-path=/var/cache/nginx/proxy_temp --http-fastcgi-temp-path=/var/cache/nginx/fastcgi_temp --http-uwsgi-temp-path=/var/cache/nginx/uwsgi_temp --http-scgi-temp-path=/var/cache/nginx/scgi_temp --user=nginx --group=nginx --with-compat --with-file-aio --with-threads --with-http_addition_module --with-http_auth_request_module --with-http_dav_module --with-http_flv_module --with-http_gunzip_module --with-http_gzip_static_module --with-http_mp4_module --with-http_random_index_module --with-http_realip_module --with-http_secure_link_module --with-http_slice_module --with-http_ssl_module --with-http_stub_status_module --with-http_sub_module --with-http_v2_module --with-mail --with-mail_ssl_module --with-stream --with-stream_realip_module --with-stream_ssl_module --with-stream_ssl_preread_module --with-cc-opt='-g -O2 -fstack-protector --param=ssp-buffer-size=4 -Wformat -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -fPIC' --with-ld-opt='-Wl,-Bsymbolic-functions -Wl,-z,relro -Wl,-z,now -Wl,--as-needed -pie'
}}}
"	defect	closed	minor		other	1.13.x	wontfix			Darwin C02NW9YVG3QD 17.5.0 Darwin Kernel Version 17.5.0: Fri Apr 13 19:32:32 PDT 2018; root:xnu-4570.51.2~1/RELEASE_X86_64 x86_64	"nginx version: nginx/1.13.12
built by clang 9.1.0 (clang-902.0.39.1)
built with OpenSSL 1.0.2o  27 Mar 2018
TLS SNI support enabled
configure arguments: --prefix=/usr/local/Cellar/nginx/1.13.12 --sbin-path=/usr/local/Cellar/nginx/1.13.12/bin/nginx --with-cc-opt='-I/usr/local/opt/pcre/include -I/usr/local/opt/openssl/include' --with-ld-opt='-L/usr/local/opt/pcre/lib -L/usr/local/opt/openssl/lib' --conf-path=/usr/local/etc/nginx/nginx.conf --pid-path=/usr/local/var/run/nginx.pid --lock-path=/usr/local/var/run/nginx.lock --http-client-body-temp-path=/usr/local/var/run/nginx/client_body_temp --http-proxy-temp-path=/usr/local/var/run/nginx/proxy_temp --http-fastcgi-temp-path=/usr/local/var/run/nginx/fastcgi_temp --http-uwsgi-temp-path=/usr/local/var/run/nginx/uwsgi_temp --http-scgi-temp-path=/usr/local/var/run/nginx/scgi_temp --http-log-path=/usr/local/var/log/nginx/access.log --error-log-path=/usr/local/var/log/nginx/error.log --with-debug --with-http_addition_module --with-http_auth_request_module --with-http_dav_module --with-http_degradation_module --with-http_flv_module --with-http_gunzip_module --with-http_gzip_static_module --with-http_mp4_module --with-http_random_index_module --with-http_realip_module --with-http_secure_link_module --with-http_slice_module --with-http_ssl_module --with-http_stub_status_module --with-http_sub_module --with-http_v2_module --with-ipv6 --with-mail --with-mail_ssl_module --with-pcre --with-pcre-jit --with-stream --with-stream_realip_module --with-stream_ssl_module --with-stream_ssl_preread_module
"