Right now this will fail on conflict, i.e. when a rule already exists. It shouldn't, such situation is a success for this method: https://github.com/openshift/cloud-provider-openstack/blob/2231e343644690f3e672c024af89d695fe20ac3c/pkg/openstack/loadbalancer.go#L2246-L2250

Same probably goes for applyNodeSecurityGroupIDForLB and applying the SG to a port.