gRPC helpers (#59)

* Add bare server

* Add test test mock starter

* Add grpc module

* Remove left over println

* Add method to remove random gRPC response

pkg/grpc/mock.go

@@ -0,0 +1,50 @@
+package grpc
+
+import (
+	"context"
+	"net"
+
+	"github.com/rs/zerolog"
+	"github.com/rs/zerolog/log"
+	"go.uber.org/fx"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
+	"google.golang.org/grpc/test/bufconn"
+)
+
+func StartTestGrpcService(lc fx.Lifecycle, server GrpcServer, logger *zerolog.Logger) *grpc.ClientConn {
+	buffer := 101024 * 1024
+	lis := bufconn.Listen(buffer)
+
+	baseServer := server.GetGrpcServer()
+	go func() {
+		if err := baseServer.Serve(lis); err != nil {
+			logger.Printf("error serving server: %v", err)
+		}
+	}()
+
+	conn, err := grpc.DialContext(context.Background(), "",
+		grpc.WithContextDialer(func(context.Context, string) (net.Conn, error) {
+			return lis.Dial()
+		}), grpc.WithTransportCredentials(insecure.NewCredentials()))
+	if err != nil {
+		logger.Printf("error connecting to server: %v", err)
+	}
+
+	closer := func() {
+		err := lis.Close()
+		if err != nil {
+			log.Printf("error closing listener: %v", err)
+		}
+		baseServer.Stop()
+	}
+
+	lc.Append(fx.Hook{
+		OnStop: func(ctx context.Context) error {
+			closer()
+			return nil
+		},
+	})
+
+	return conn
+}

pkg/grpc/module.go

@@ -0,0 +1,9 @@
+package grpc
+
+import "go.uber.org/fx"
+
+var Module = fx.Options(
+	fx.Provide(
+		NewServer,
+	),
+)

pkg/grpc/server.go

@@ -0,0 +1,56 @@
+package grpc
+
+import (
+	"context"
+	"fmt"
+	"net"
+
+	"github.com/rs/zerolog"
+	"google.golang.org/grpc"
+)
+
+type BareServer struct {
+	Server *grpc.Server
+}
+
+func NewServer(logger *zerolog.Logger) *BareServer {
+	grpcServer := &BareServer{}
+
+	sv := grpc.NewServer(
+		grpc.UnaryInterceptor(
+			grpcLoggerInterceptor(logger),
+		),
+	)
+	grpcServer.Server = sv
+
+	return grpcServer
+}
+
+func (s *BareServer) GetListener() (net.Listener, error) {
+	lis, err := net.Listen("tcp", fmt.Sprintf(":%d", 50051))
+	if err != nil {
+		return nil, err
+	}
+
+	return lis, nil
+}
+
+func (s *BareServer) GetGrpcServer() *grpc.Server {
+	return s.Server
+}
+
+func grpcLoggerInterceptor(logger *zerolog.Logger) func(context.Context, interface{}, *grpc.UnaryServerInfo, grpc.UnaryHandler) (interface{}, error) {
+	return func(ctx context.Context,
+		req interface{},
+		_ *grpc.UnaryServerInfo,
+		handler grpc.UnaryHandler,
+	) (interface{}, error) {
+		// Add logger to context
+		lctx := logger.WithContext(ctx)
+
+		// Calls the handler
+		h, err := handler(lctx, req)
+
+		return h, err
+	}
+}

pkg/grpc/snapshot.go

@@ -0,0 +1,16 @@
+package grpc
+
+import "strings"
+
+type ProtoMessage interface {
+	String() string
+}
+
+// StringifySnapshot converts a protobuf response to a string and removes all double spaces.
+// This is needed because of a pseudo-random effect https://github.com/golang/protobuf/issues/1121
+func StringifySnapshot(resp ProtoMessage) string {
+	respStr := resp.String()
+	respStr = strings.ReplaceAll(respStr, "  ", " ")
+
+	return respStr
+}