Add broker service implementation

broker/service/handler/handler.go

@@ -0,0 +1,57 @@
+package handler
+
+import (
+	"context"
+
+	"github.com/micro/go-micro/broker"
+	pb "github.com/micro/go-micro/broker/service/proto"
+	"github.com/micro/go-micro/errors"
+)
+
+type Broker struct {
+	Broker broker.Broker
+}
+
+func (b *Broker) Publish(ctx context.Context, req *pb.PublishRequest, rsp *pb.Empty) error {
+	err := b.Broker.Publish(req.Topic, &broker.Message{
+		Header: req.Message.Header,
+		Body:   req.Message.Body,
+	})
+	if err != nil {
+		return errors.InternalServerError("go.micro.broker", err.Error())
+	}
+	return nil
+}
+
+func (b *Broker) Subscribe(ctx context.Context, req *pb.SubscribeRequest, stream pb.Broker_SubscribeStream) error {
+	errChan := make(chan error, 1)
+
+	// message handler to stream back messages from broker
+	handler := func(p broker.Event) error {
+		if err := stream.Send(&pb.Message{
+			Header: p.Message().Header,
+			Body:   p.Message().Body,
+		}); err != nil {
+			select {
+			case errChan <- err:
+				return err
+			default:
+				return err
+			}
+		}
+		return nil
+	}
+
+	sub, err := b.Broker.Subscribe(req.Topic, handler, broker.Queue(req.Queue))
+	if err != nil {
+		return errors.InternalServerError("go.micro.broker", err.Error())
+	}
+	defer sub.Unsubscribe()
+
+	select {
+	case <-ctx.Done():
+		return nil
+	case <-errChan:
+		return err
+	}
+}