Merge pull request #1 from joelurraco/grpc_gw_options

Grpc gw options

cmd/sample/impl/status.go

@@ -7,6 +7,8 @@ import (
 	"bitbucket.org/acbapis/acbapis/common"
 	"bitbucket.org/acbapis/acbapis/status"
 	"github.com/jllopis/mifo/version"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/metadata"
 )
 
 // StatusService provides a service that offers basic status functionality:
@@ -17,11 +19,19 @@ type StatusService struct{}
 
 // GetServerTime returns the current UTC server time in nanoseconds
 func (st *StatusService) GetServerTime(ctx context.Context, empty *common.EmptyMessage) (*status.ServerTimeMessage, error) {
+	headerVal := "max-age=600, s-maxage=600"
+	grpc.SetHeader(ctx, metadata.Pairs("Grpc-Metadata-Cache-Control", headerVal))
+	grpc.SetHeader(ctx, metadata.Pairs("Grpc-Metadata-X-App-Cache-Control", headerVal))
+
 	return &status.ServerTimeMessage{Value: time.Now().UTC().UnixNano()}, nil
 }
 
 // GetVersion returns the current API Version. It is a direct mapping from go-version "github.com/hashicorp/go-version.Version
 func (st *StatusService) GetVersion(ctx context.Context, empty *common.EmptyMessage) (*common.Version, error) {
+	headerVal := "max-age=600, s-maxage=600"
+	grpc.SetHeader(ctx, metadata.Pairs("Grpc-Metadata-Cache-Control", headerVal))
+	grpc.SetHeader(ctx, metadata.Pairs("Grpc-Metadata-X-App-Cache-Control", headerVal))
+
 	return &common.Version{
 		Version:    version.Version,
 		APIVersion: version.APIVersion,
@@ -31,6 +41,10 @@ func (st *StatusService) GetVersion(ctx context.Context, empty *common.EmptyMess
 }
 
 func (st *StatusService) GetGlobalServiceStatus(ctx context.Context, empty *common.EmptyMessage) (*status.ServerStatusMessage, error) {
+	headerVal := "max-age=600, s-maxage=600"
+	grpc.SetHeader(ctx, metadata.Pairs("Grpc-Metadata-Cache-Control", headerVal))
+	grpc.SetHeader(ctx, metadata.Pairs("Grpc-Metadata-X-App-Cache-Control", headerVal))
+
 	serverStatus := &status.ServerStatusMessage{
 		Status: status.ServerStatus_OK,
 	}

cmd/sample/main.go

@@ -54,7 +54,12 @@ func main() {
 	api.Register(statusRegistrator)
 
 	// Use grpc-gw ...
-	api.UseGrpcGw()
+	api.UseGrpcGw(
+		mifo.WithCORS(),
+		mifo.WithMetrics(),
+		mifo.LogRequests(),
+		mifo.WithOutgoingHeaderMatcher(runtime.DefaultHeaderMatcher),
+	)
 	// ... and register http proxy services
 	opts := []grpc.DialOption{
 		grpc.WithInsecure(),

microserver.go

@@ -28,6 +28,7 @@ type GrpcServer struct {
 	HttpMux      *http.ServeMux
 	HttpSrv      *http.Server
 	GrpcGwMux    *runtime.ServeMux
+	grpcGwOpts   options
 	// Interceptors
 	UnaryInter               []grpc.UnaryServerInterceptor
 	StreamInter              []grpc.StreamServerInterceptor

options.go

@@ -12,6 +12,39 @@ import (
 	"github.com/soheilhy/cmux"
 )
 
+type options struct {
+	cors                  bool
+	metrics               bool
+	logRequests           bool
+	outgoingHeaderMatcher runtime.HeaderMatcherFunc
+}
+
+type Option func(*options)
+
+func WithCORS() Option {
+	return func(o *options) {
+		o.cors = true
+	}
+}
+
+func WithMetrics() Option {
+	return func(o *options) {
+		o.metrics = true
+	}
+}
+
+func WithOutgoingHeaderMatcher(fn runtime.HeaderMatcherFunc) Option {
+	return func(o *options) {
+		o.outgoingHeaderMatcher = fn
+	}
+}
+
+func LogRequests() Option {
+	return func(o *options) {
+		o.logRequests = true
+	}
+}
+
 func (g *GrpcServer) WithListener(l net.Listener) *GrpcServer {
 	// Crear el muxer cmux
 	g.CmuxSrv = newCMux(l)
@@ -49,21 +82,49 @@ func (g *GrpcServer) UseReflection() *GrpcServer {
 	return g
 }
 
-func (g *GrpcServer) UseGrpcGw() *GrpcServer {
-	g.GrpcGwMux = runtime.NewServeMux()
-	g.HttpMux.Handle("/", logh(g.GrpcGwMux))
+func (g *GrpcServer) UseGrpcGw(opts ...Option) *GrpcServer {
+	grpcGwOpts := &options{}
+	for _, opt := range opts {
+		opt(grpcGwOpts)
+	}
+
+	g.grpcGwOpts = *grpcGwOpts
+
+	outgoingHeaderMatcher := g.grpcGwOpts.outgoingHeaderMatcher
+	g.GrpcGwMux = runtime.NewServeMux(runtime.WithOutgoingHeaderMatcher(outgoingHeaderMatcher))
+	g.HttpMux.Handle("/", g.indexHandler(g.GrpcGwMux))
 	return g
 }
 
 func (g *GrpcServer) String() string {
 	return fmt.Sprintf("gRPC Microservice\n=================\n  Name: %s\n  ID: %s\n", g.Name, g.ID)
 }
 
-func logh(handler http.Handler) http.Handler {
+func (g *GrpcServer) indexHandler(handler http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		log.Info(fmt.Sprintf("%s %s %s", r.RemoteAddr, r.Method, r.URL))
-		// Registrar llamada REST
-		metrics.Counter("rest.requests").Add()
+		if g.grpcGwOpts.logRequests {
+			log.Info(fmt.Sprintf("%s %s %s", r.RemoteAddr, r.Method, r.URL))
+		}
+
+		if g.grpcGwOpts.metrics {
+			// Registrar llamada REST
+			metrics.Counter("rest.requests").Add()
+		}
+
+		if g.grpcGwOpts.cors {
+			enableCors(&w)
+
+			if r.Method == "OPTIONS" {
+				return
+			}
+		}
+
 		handler.ServeHTTP(w, r)
 	})
 }
+
+func enableCors(w *http.ResponseWriter) {
+	(*w).Header().Set("Access-Control-Allow-Origin", "*")
+	(*w).Header().Set("Access-Control-Allow-Methods", "POST, GET, OPTIONS, PUT, DELETE")
+	(*w).Header().Set("Access-Control-Allow-Headers", "Accept, Content-Type, Content-Length, Accept-Encoding, X-CSRF-Token, Authorization")
+}