address tim's feedback

lib/autoupdate/rollout/controller.go

@@ -46,15 +46,24 @@ type Controller struct {
 }
 
 // NewController creates a new Controller for the autoupdate_agent_rollout kind.
-func NewController(client Client, log *slog.Logger, clock clockwork.Clock) *Controller {
+func NewController(client Client, log *slog.Logger, clock clockwork.Clock) (*Controller, error) {
+	if client == nil {
+		return nil, trace.BadParameter("missing client")
+	}
+	if log == nil {
+		return nil, trace.BadParameter("missing log")
+	}
+	if clock == nil {
+		return nil, trace.BadParameter("missing clock")
+	}
 	return &Controller{
 		clock: clock,
 		log:   log,
 		reconciler: reconciler{
 			clt: client,
 			log: log,
 		},
-	}
+	}, nil
 }
 
 // Run the autoupdate_agent_rollout controller. This function returns only when its context is canceled.

lib/service/service.go

@@ -2431,7 +2431,10 @@ func (process *TeleportProcess) initAuthService() error {
 		return trace.Wrap(spiffeFedSyncer.Run(process.GracefulExitContext()), "running SPIFFEFederation Syncer")
 	})
 
-	agentRolloutController := rollout.NewController(authServer, logger, process.Clock)
+	agentRolloutController, err := rollout.NewController(authServer, logger, process.Clock)
+	if err != nil {
+		return trace.Wrap(err, "creating the rollout controller")
+	}
 	process.RegisterFunc("auth.autoupdate_agent_rollout_controller", func() error {
 		return trace.Wrap(agentRolloutController.Run(process.GracefulExitContext()), "running autoupdate_agent_rollout controller")
 	})