Instantiate default agent dispatches in rtc for better backward compatibility (#2886)

pkg/agent/client.go

@@ -122,7 +122,11 @@ func (c *agentClient) LaunchJob(ctx context.Context, desc *JobRequest) *serverut
 	dispatcher := c.getDispatcher(desc.AgentName, desc.JobType)
 
 	if dispatcher == nil {
-		logger.Infow("not dispatching agent job since no worker is available", "agentName", desc.AgentName, "jobType", desc.JobType)
+		logger.Infow("not dispatching agent job since no worker is available",
+			"agentName", desc.AgentName,
+			"jobType", desc.JobType,
+			"room", desc.Room.Name,
+			"roomID", desc.Room.Sid)
 		return ret
 	}
 
@@ -183,6 +187,12 @@ func (c *agentClient) getDispatcher(agName string, jobType livekit.JobType) *ser
 	}
 	c.mu.Unlock()
 
+	if agName == "" {
+		// if no agent name is given, we would need to dispatch backwards compatible mode
+		// which means dispatching to each of the namespaces
+		return target
+	}
+
 	done := make(chan *serverutils.IncrementalDispatcher[string], 1)
 	c.workers.Submit(func() {
 		agentNames.ForEach(func(ag string) {

pkg/rtc/room.go

@@ -1488,7 +1488,15 @@ func (r *Room) createAgentDispatchesFromRoomAgent() {
 		return
 	}
 
-	for _, ag := range r.internal.AgentDispatches {
+	roomDisp := r.internal.AgentDispatches
+	if len(roomDisp) == 0 {
+		// Backward compatibility: by default, start any agent in the empty JobName
+		roomDisp = []*livekit.RoomAgentDispatch{
+			&livekit.RoomAgentDispatch{},
+		}
+	}
+
+	for _, ag := range roomDisp {
 		ad := &livekit.AgentDispatch{
 			Id:        guid.New(guid.AgentDispatchPrefix),
 			AgentName: ag.AgentName,

pkg/service/roomallocator.go

@@ -106,15 +106,9 @@ func (r *StandardRoomAllocator) CreateRoom(ctx context.Context, req *livekit.Cre
 			internal.TrackEgress = req.Egress.Tracks
 		}
 	}
-	if req.Agent == nil {
-		// Backward compatibility: by default, start any agent in the empty JobName
-		req.Agent = &livekit.RoomAgent{
-			Dispatches: []*livekit.RoomAgentDispatch{
-				&livekit.RoomAgentDispatch{},
-			},
-		}
+	if req.Agent != nil {
+		internal.AgentDispatches = req.Agent.Dispatches
 	}
-	internal.AgentDispatches = req.Agent.Dispatches
 	if req.MinPlayoutDelay > 0 || req.MaxPlayoutDelay > 0 {
 		internal.PlayoutDelay = &livekit.PlayoutDelay{
 			Enabled: true,