graphql-gateway

graphql-gateway

This project is currently in WIP.

Installation

go get -u github.com/grpc-custom/graphql-gateway/cmd/protoc-gen-graphql-gateway

Usage

1. Define your gRPC service using protocol buffers

   example.proto

   syntax = "proto3";
   package example;
   
   import "github.com/grpc-custom/graphql-gateway/graphql.proto";
   
   message User {
     int32 id    = 1;
     string name = 2;
   }
   
   message GetRequest {
     int32 id = 1;
   }
   
   message GetResponse {
     User user = 1;
   }
   
   service UserService {
     rpc Get(GetRequest) returns (GetResponse) {
       option (grpc_custom.graphql.schema) = {
         query: "getUser"
       };
     }
   }
   

2. Generate GraphQL server using protoc-gen-graphql-gateway

   protoc -I=${GOPATH}/src:. \
       --go_out=plugins=grpc:. \
       --graphql-gateway_out=. \
       path/to/example.proto
   

   It will generate a GraphQL server path/to/example.pb.gql.go

3. Write an entrypoint for the GraphQL server

   package main
   
   import (
       "context"
       "log"
       "net/http"
   
       "github.com/grpc-custom/graphql-gateway/runtime"
       "google.golang.org/grpc"
   
       gql "path/to/example_service_package"
   )
   
   func main() {
       ctx := context.Background()
       ctx, cancel := context.WithCancel(ctx)
       defer cancel()
   
       mux, err := runtime.NewServeMux()
       if err != nil {
           log.Fatal(err)
       }
       // Register gRPC server endpoint
       opts := []grpc.DialOption{grpc.WithInsecure()}
       host := "localhost:9090" // gRPC server endpoint
       err = gql.RegisterUserServiceFromEndpoint(ctx, mux, host, opts)
       if err != nil {
           log.Fatal(err)
       }
       // Start GraphQL server
       err = http.ListenAndServe(":8080", mux)
       if err != nil {
           log.Fatal(err)
       }
   }
   

Examples

examples

TODO

• Apollo Persisted Queries
• complexity
• data loader
• custom error handling
• subscribe
  • websocket
• enum (string)
• message pack
• cache control
  • redis
  • memcache
• graphql schema
• open trace