Got "gRPC requires HTTP/2" running grpcwebproxy

[vintikzzz]

Hi!
Just want to highlight issue mentioned by @n0mer at #109

Run proxy, everything looks fine

MacBook-Pro:grpcwebproxy vintik$ ./grpcwebproxy --backend_addr=10.105.27.225:4340 --run_tls_server=false
INFO[0000] parsed scheme: ""                             system=system
INFO[0000] scheme "" not registered, fallback to default scheme  system=system
INFO[0000] ccResolverWrapper: sending new addresses to cc: [{10.105.27.225:4340 0  <nil>}]  system=system
INFO[0000] ClientConn switching balancer to "pick_first"  system=system
INFO[0000] pickfirstBalancer: HandleSubConnStateChange: 0xc4200b5400, CONNECTING  system=system
INFO[0000] listening for http on: [::]:8080
INFO[0000] pickfirstBalancer: HandleSubConnStateChange: 0xc4200b5400, READY  system=system

But curl returns gRPC requires HTTP/2

MacBook-Pro:server vintik$ curl 127.0.0.1:8080
gRPC requires HTTP/2

I have to use dep because of #174 and here is it's status:

MacBook-Pro:grpcwebproxy vintik$ dep status
PROJECT                                           CONSTRAINT     VERSION        REVISION  LATEST   PKGS USED
github.com/beorn7/perks                           branch master  branch master  3a771d9   3a771d9  1
github.com/golang/protobuf                        branch master  branch master  3a3da3a   3a3da3a  7
github.com/gorilla/websocket                      v1.2.0         v1.2.0         ea4d1f6   v1.2.0   1
github.com/grpc-ecosystem/go-grpc-middleware      ^1.0.0         v1.0.0         c250d65   v1.0.0   6
github.com/grpc-ecosystem/go-grpc-prometheus      ^1.2.0         v1.2.0         c225b8c   v1.2.0   1
github.com/improbable-eng/grpc-web                ^0.6.2         0.6.2          72eb701   0.6.2    1
github.com/matttproud/golang_protobuf_extensions  v1.0.1         v1.0.1         c12348c   v1.0.1   1
github.com/mwitkow/go-conntrack                   branch master  branch master  cc309e4   cc309e4  2
github.com/mwitkow/grpc-proxy                     branch master  branch master  67591eb   67591eb  1
github.com/prometheus/client_golang               ^0.8.0         v0.8.0         c5b7fcc   v0.8.0   2
github.com/prometheus/client_model                branch master  branch master  99fa1f4   99fa1f4  1
github.com/prometheus/common                      branch master  branch master  7600349   7600349  3
github.com/prometheus/procfs                      branch master  branch master  9466342   9466342  4
github.com/rs/cors                                v1.4.0         v1.4.0         ca016a0   v1.4.0   1
github.com/sirupsen/logrus                        ^1.0.5         v1.0.5         c155da1   v1.0.5   1
github.com/spf13/pflag                            ^1.0.1         v1.0.1         583c0c0   v1.0.1   1
golang.org/x/crypto                               branch master  branch master  df8d471   df8d471  1
golang.org/x/net                                  branch master  branch master  1e49130   1e49130  7
golang.org/x/sys                                  branch master  branch master  c11f84a   c11f84a  2
golang.org/x/text                                 v0.3.0         v0.3.0         f21a4df   v0.3.0   14
google.golang.org/genproto                        branch master  branch master  81158ef   81158ef  1
google.golang.org/grpc                            1.10.1         v1.10.1        61763f5   v1.10.1  23

[met-pub]

the same

[johanbrandhorst]

I think the issue here is that you're not using the correct headers, so what the gRPC-Web proxy does is just assume your request is a normal gRPC request, and sends it along to the backend gRPC server, which provides this response. If you want to test with cURL, make sure you specify the correct Content-Type header: Content-Type: application/grpc-web+proto.

[natemurthy]

@johanbrandhorst Can we re-open this ticket or #109 ? I'm also observing the same thing in my web browser client using grpcwebproxy-0.6.3 and grpcwebproxy-0.7.0:

And when I use curl:

curl -D - http://localhost:9000/Proxy/Ping -H 'Content-Type: application/grpc-web+proto'
HTTP/1.1 500 Internal Server Error
Date: Wed, 06 Feb 2019 20:09:26 GMT
Content-Type: text/plain; charset=utf-8
Content-Length: 21
Connection: keep-alive

gRPC requires HTTP/2

[rbautisf]

Is there any update on this one?

[johanbrandhorst]

This sort of error implies that the wrapper isn't in use, do you have an example code that suffers this?