Introduce "noop" go-micro broker

This introduces a no op broker for go-micro. It is set as the default
broker for all ocis http services. To avoid starting the default http
broker, which opens an unused random http port.

Fixes: https://github.com/owncloud/ocis/issues/3829

ocis-pkg/broker/noop.go

@@ -0,0 +1,45 @@
+package broker
+
+import (
+	"errors"
+
+	"go-micro.dev/v4/broker"
+)
+
+type NoOp struct{}
+
+func (n NoOp) Init(_ ...broker.Option) error {
+	return nil
+}
+
+func (n NoOp) Options() broker.Options {
+	return broker.Options{}
+}
+
+func (n NoOp) Address() string {
+	return ""
+}
+
+func (n NoOp) Connect() error {
+	return nil
+}
+
+func (n NoOp) Disconnect() error {
+	return nil
+}
+
+func (n NoOp) Publish(topic string, m *broker.Message, opts ...broker.PublishOption) error {
+	return nil
+}
+
+func (n NoOp) Subscribe(topic string, h broker.Handler, opts ...broker.SubscribeOption) (broker.Subscriber, error) {
+	return nil, errors.New("not implemented")
+}
+
+func (n NoOp) String() string {
+	return "NoOp"
+}
+
+func NewBroker(_ ...broker.Option) broker.Broker {
+	return &NoOp{}
+}

ocis-pkg/service/external/external.go

@@ -6,7 +6,6 @@ import (
 
 	"github.com/owncloud/ocis/v2/ocis-pkg/log"
 	oregistry "github.com/owncloud/ocis/v2/ocis-pkg/registry"
-	"go-micro.dev/v4/broker"
 	"go-micro.dev/v4/registry"
 )
 
@@ -20,7 +19,6 @@ func RegisterGRPCEndpoint(ctx context.Context, serviceID, uuid, addr string, ver
 	}
 	ocisRegistry := oregistry.GetRegistry()
 
-	node.Metadata["broker"] = broker.String()
 	node.Metadata["registry"] = ocisRegistry.String()
 	node.Metadata["server"] = "grpc"
 	node.Metadata["transport"] = "grpc"
@@ -76,7 +74,6 @@ func RegisterHTTPEndpoint(ctx context.Context, serviceID, uuid, addr string, ver
 	}
 	ocisRegistry := oregistry.GetRegistry()
 
-	node.Metadata["broker"] = broker.String()
 	node.Metadata["registry"] = ocisRegistry.String()
 	node.Metadata["server"] = "http"
 	node.Metadata["transport"] = "http"

ocis-pkg/service/http/service.go

@@ -4,6 +4,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/owncloud/ocis/v2/ocis-pkg/broker"
 	"github.com/owncloud/ocis/v2/ocis-pkg/registry"
 
 	mhttps "github.com/go-micro/plugins/v4/server/http"
@@ -18,9 +19,11 @@ type Service struct {
 
 // NewService initializes a new http service.
 func NewService(opts ...Option) Service {
+	noopBroker := broker.NoOp{}
 	sopts := newOptions(opts...)
 	wopts := []micro.Option{
 		micro.Server(mhttps.NewServer(server.TLSConfig(sopts.TLSConfig))),
+		micro.Broker(noopBroker),
 		micro.Address(sopts.Address),
 		micro.Name(strings.Join([]string{sopts.Namespace, sopts.Name}, ".")),
 		micro.Version(sopts.Version),