How to handle multiple endpoints via grpc-gateway? - go

Question

I'm sure all the services are working properly.
I have the code below:
This snippet is used for registering two endpoints.
func RegisterEndpoints(ctx context.Context, c *utils.AppConfig, r resolver.Builder) (http.Handler, error) {
var err error
mux := runtime.NewServeMux()
dialOpts := []grpc.DialOption{grpc.WithBalancerName("round_robin"), grpc.WithInsecure()}
err = protos.RegisterUserCenterHandlerFromEndpoint(ctx, mux, r.Scheme()+"://author/user-center", dialOpts)
if err != nil {
return nil, err
}
err = protos.RegisterSsoHandlerFromEndpoint(ctx, mux, r.Scheme()+"://author/sso", dialOpts)
if err != nil {
return nil, err
}
return mux, nil
}
And in my main.go，I build a resolver to resolve name to address, then register the two endpoints and listen on port 8080.
func run() error {
c := utils.GetAppConfig()
ctx := context.Background()
ctx, cancel := context.WithCancel(ctx)
defer cancel()
r := localresolver.NewResolver(fmt.Sprintf("%s:%d", c.Registry.Host, c.Registry.Port))
resolver.Register(r)
mux := http.NewServeMux()
// Register endpoints here
gw, err := routes.RegisterEndpoints(ctx, c, r)
if err != nil {
return err
}
mux.Handle("/", gw)
fmt.Println("Listening localhost:8080...")
return http.ListenAndServe(fmt.Sprintf("%s:%d", c.Gateway.Host, c.Gateway.Port), mux)
}
func main() {
defer glog.Flush()
if err := run(); err != nil {
glog.Fatal(err)
}
}
But after I ran go run main.go, I found that only the last service I registered can be accessed, that is sso service (the err = protos.RegisterSsoHandlerFromEndpoint(ctx, mux, r.Scheme()+"://author/sso", dialOpts) line).
Can anyone show me an example of the correct way to register multiple endpoints via grpc-gateway? (make all the services registered with grpc-gateway can successfully be visited)
[2020-01-31] Need more help, now my code is like below:
Other code are same as before.
Additional, this is the result which name resolver shows:

Answer 1

There is no need to pass the ServeMux (gw) to mux var as handler, you can just ListenAndServe to the returned gw variable.
// Register endpoints here
gw, err := routes.RegisterEndpoints(ctx, c, r)
if err != nil {
return err
}
fmt.Println("Listening localhost:8080...")
return http.ListenAndServe(fmt.Sprintf("%s:%d", c.Gateway.Host, c.Gateway.Port), gw)
and in RegisterEndpoints function, the endpoint parameter should be your host:port, the api endpoint should be provided in the google api annotation in the proto file.
err = protos.RegisterUserCenterHandlerFromEndpoint(ctx, mux, fmt.Sprintf("%s:%d", c.Gateway.Host, c.Gateway.Port), dialOpts)
if err != nil {
return nil, err
}
err = protos.RegisterSsoHandlerFromEndpoint(ctx, mux, fmt.Sprintf("%s:%d", c.Gateway.Host, c.Gateway.Port), dialOpts)
if err != nil {
return nil, err
}

Answer 2

I appended grpc.WithBlock() to grpc.DialOption, then all services can be accessed via grpc-gateway now.
Like below:
dialOpts := []grpc.DialOption{grpc.WithBalancerName("round_robin"), grpc.WithInsecure(), grpc.WithBlock()}