grpc gateway cors

README.md

import (
 // ...
 "github.com/rs/cors" 
)

// ...
mux := runtime.NewServeMux()
proto.RegisterXYZServiceHandler(ctx, mux, conn)

withCors := cors.New(cors.Options{
  AllowOriginFunc:  func(origin string) bool { return true },
  AllowedMethods:   []string{"GET", "POST", "PATCH", "PUT", "DELETE", "OPTIONS"},
  AllowedHeaders:   []string{"ACCEPT", "Authorization", "Content-Type", "X-CSRF-Token"},
  ExposedHeaders:   []string{"Link"},
  AllowCredentials: true,
  MaxAge:           300,
}).Handler(mux)

s.httpServer = &http.Server{
  Addr:    ":8080",
  Handler: withCors,
}
// ...