make graph service events optional

changelog/unreleased/feature-optional-events-in-graph-service.md

@@ -0,0 +1,8 @@
+Enhancement: Optional events in graph service
+
+We've changed the graph service so that you also can start it without any
+event bus.
+Therefore you need to set `GRAPH_EVENTS_ENDPOINT` to an empty string.
+The graph API will not emit any events in this case.
+
+https://github.com/owncloud/ocis/pull/55555

services/graph/pkg/config/config.go

@@ -69,6 +69,6 @@ type Identity struct {
 
 // Events combines the configuration options for the event bus.
 type Events struct {
-	Endpoint string `yaml:"endpoint" env:"GRAPH_EVENTS_ENDPOINT" desc:"The address of the streaming service."`
+	Endpoint string `yaml:"endpoint" env:"GRAPH_EVENTS_ENDPOINT" desc:"The address of the streaming service. Set to a empty string to disable emitting events."`
 	Cluster  string `yaml:"cluster" env:"GRAPH_EVENTS_CLUSTER" desc:"The clusterID of the streaming service. Mandatory when using the NATS service."`
 }

services/graph/pkg/server/http/server.go

@@ -12,6 +12,7 @@ import (
 	svc "github.com/owncloud/ocis/v2/services/graph/pkg/service/v0"
 	"github.com/pkg/errors"
 	"go-micro.dev/v4"
+	"go-micro.dev/v4/events"
 )
 
 // Server initializes the http service and server.
@@ -28,15 +29,20 @@ func Server(opts ...Option) (http.Service, error) {
 		http.Flags(options.Flags...),
 	)
 
-	publisher, err := server.NewNatsStream(
+	var publisher events.Stream
-		natsjs.Address(options.Config.Events.Endpoint),
+
-		natsjs.ClusterID(options.Config.Events.Cluster),
+	if options.Config.Events.Endpoint != "" {
-	)
+		var err error
-	if err != nil {
+		publisher, err = server.NewNatsStream(
-		options.Logger.Error().
+			natsjs.Address(options.Config.Events.Endpoint),
-			Err(err).
+			natsjs.ClusterID(options.Config.Events.Cluster),
-			Msg("Error initializing events publisher")
+		)
-		return http.Service{}, errors.Wrap(err, "could not initialize events publisher")
+		if err != nil {
+			options.Logger.Error().
+				Err(err).
+				Msg("Error initializing events publisher")
+			return http.Service{}, errors.Wrap(err, "could not initialize events publisher")
+		}
 	}
 
 	handle := svc.NewService(

services/graph/pkg/service/v0/graph.go

@@ -91,10 +91,12 @@ func (g Graph) GetGatewayClient() GatewayClient {
 }
 
 func (g Graph) publishEvent(ev interface{}) {
-	if err := events.Publish(g.eventsPublisher, ev); err != nil {
+	if g.eventsPublisher != nil {
-		g.logger.Error().
+		if err := events.Publish(g.eventsPublisher, ev); err != nil {
-			Err(err).
+			g.logger.Error().
-			Msg("could not publish user created event")
+				Err(err).
+				Msg("could not publish user created event")
+		}
 	}
 }