not assign floating ip when there are multiple controller nodes

docs/book/src/clusteropenstack/configuration.md

@@ -153,6 +153,12 @@ openstack floating ip create <public network>
 
 Note: Only user with admin role can create a floating IP with specific IP.
 
+Note: When associate floating ip to a cluster with more than 1 controller nodes, the floating ip will be
+associated to the first controller node and the other controller nodes doesn't have floating ip. When
+ the controller node has the floating ip is down CAPO will NOT auto assign the floating ip address
+to any other controller node. So we recommend to only set one controller node when floating ip is needed,
+or please consider using loadbalancer instead, see [issue 1265](https://github.com/kubernetes-sigs/cluster-api-provider-openstack/issues/1265) for further information.
+
 ### Disabling the API server floating IP
 
 It is possible to provision a cluster without a floating IP for the API server by setting

pkg/cloud/services/networking/floatingip.go

@@ -122,8 +122,13 @@ var backoff = wait.Backoff{
 func (s *Service) AssociateFloatingIP(eventObject runtime.Object, fp *floatingips.FloatingIP, portID string) error {
 	s.scope.Logger.Info("Associating floating IP", "id", fp.ID, "ip", fp.FloatingIP)
 
+	if len(fp.PortID) != 0{
+		s.scope.Logger.Info("Floating IP already associated to other port:", "id", fp.ID, "fixed ip", fp.FixedIP)
+		return nil
+	}
+
 	if fp.PortID == portID {
-		s.scope.Logger.Info("Floating IP already associated:", "id", fp.ID, "ip", fp.FloatingIP)
+		s.scope.Logger.Info("Floating IP already associated to same port:", "id", fp.ID, "ip", fp.FloatingIP)
 		return nil
 	}