Fix deleting empty monitors

pkg/cloudprovider/providers/openstack/openstack_loadbalancer.go

@@ -763,10 +763,14 @@ func (lbaas *LbaasV2) EnsureLoadBalancer(clusterName string, apiService *v1.Serv
 			}
 			waitLoadbalancerActiveProvisioningStatus(lbaas.network, loadbalancer.ID)
 			monitorID = monitor.ID
+		} else if lbaas.opts.CreateMonitor == false {
+			glog.V(4).Infof("Do not create monitor for pool %s when create-monitor is false", pool.ID)
 		}
 
+		if monitorID != "" {
 			glog.V(4).Infof("Monitor for pool %s: %s", pool.ID, monitorID)
 		}
+	}
 
 	// All remaining listeners are obsolete, delete
 	for _, listener := range oldListeners {
@@ -1106,8 +1110,11 @@ func (lbaas *LbaasV2) EnsureLoadBalancerDeleted(clusterName string, service *v1.
 			return fmt.Errorf("Error getting pool for listener %s: %v", listener.ID, err)
 		}
 		poolIDs = append(poolIDs, pool.ID)
+		// If create-monitor of cloud-config is false, pool has not monitor.
+		if pool.MonitorID != "" {
 			monitorIDs = append(monitorIDs, pool.MonitorID)
 		}
+	}
 
 	// get all members associated with each poolIDs
 	var memberIDs []string