Wait for libvirt connection in hypervisor controller

Author: PhilippMatthes

internal/controller/hypervisor_controller.go

@@ -58,6 +58,11 @@ type HypervisorReconciler struct {
 
 	// Channel that can be used to trigger reconcile events.
 	reconcileCh chan event.GenericEvent
+
+	// An interval that determines how long to wait between connection attempts
+	// to libvirt. This is used in the Start method when trying to connect to
+	// libvirt, and can be set to a lower value for testing purposes.
+	libvirtConnectInterval time.Duration
 }
 
 const (
@@ -326,11 +331,20 @@ func (r *HypervisorReconciler) Start(ctx context.Context) error {
 	log := logger.FromContext(ctx, "controller", "hypervisor")
 	log.Info("starting libvirt event subscription")
 
-	// Ensure we're connected to libvirt.
-	if err := r.Libvirt.Connect(); err != nil {
-		log.Error(err, "unable to connect to libvirt")
-		return err
+	// Block until we're connected to libvirt.
+	for {
+		timeToSleep := r.libvirtConnectInterval
+		if timeToSleep == 0 {
+			timeToSleep = 5 * time.Second // default value
+		}
+		if err := r.Libvirt.Connect(); err != nil {
+			log.Error(err, "unable to connect to libvirt, retrying in 5 seconds")
+			time.Sleep(timeToSleep)
+			continue
+		}
+		break
 	}
+	log.Info("connected to libvirt")
 
 	// Run a ticker which reconciles the hypervisor resource every minute.
 	// This ensures that we periodically reconcile the hypervisor even