[occm] Delete sgs on reconfiguration (kubernetes#2305)

* Use errors.IsNotFound()

SG management code used its own function to check if `err` is a 404. We
have a dedicated function for that, let's use it there too.

* Make sure SGs are deleted when CPO is reconfigured

If we reconfigure CPO to set `manage-security-groups=true`, it will
correctly reconcile LBs to make sure SGs are created and associated with
nodes.  This commit makes sure that SGs are properly deleted when CPO is
reconfigured in opposite direction, with `manage-security-groups=false`.

Author: dulek

pkg/openstack/loadbalancer.go

@@ -797,21 +797,6 @@ func disassociateSecurityGroupForLB(network *gophercloud.ServiceClient, sg strin
 	return nil
 }
 
-// isSecurityGroupNotFound return true while 'err' is object of gophercloud.ErrResourceNotFound
-func isSecurityGroupNotFound(err error) bool {
-	errType := reflect.TypeOf(err).String()
-	errTypeSlice := strings.Split(errType, ".")
-	errTypeValue := ""
-	if len(errTypeSlice) != 0 {
-		errTypeValue = errTypeSlice[len(errTypeSlice)-1]
-	}
-	if errTypeValue == "ErrResourceNotFound" {
-		return true
-	}
-
-	return false
-}
-
 // deleteListeners deletes listeners and its default pool.
 func (lbaas *LbaasV2) deleteListeners(lbID string, listenerList []listeners.Listener) error {
 	for _, listener := range listenerList {
@@ -2059,6 +2044,12 @@ func (lbaas *LbaasV2) ensureOctaviaLoadBalancer(ctx context.Context, clusterName
 		if err != nil {
 			return status, fmt.Errorf("failed when reconciling security groups for LB service %v/%v: %v", service.Namespace, service.Name, err)
 		}
+	} else {
+		// Attempt to delete the SG if `manage-security-groups` is disabled. When CPO is reconfigured to enable it we
+		// will reconcile the LB and create the SG. This is to make sure it works the same in the opposite direction.
+		if err := lbaas.EnsureSecurityGroupDeleted(clusterName, service); err != nil {
+			return status, err
+		}
 	}
 
 	return status, nil
@@ -2190,6 +2181,9 @@ func (lbaas *LbaasV2) updateOctaviaLoadBalancer(ctx context.Context, clusterName
 			return fmt.Errorf("failed to update Security Group for loadbalancer service %s: %v", serviceName, err)
 		}
 	}
+	// We don't try to lookup and delete the SG here when `manage-security-group=false` as `UpdateLoadBalancer()` is
+	// only called on changes to the list of the Nodes. Deletion of the SG on reconfiguration will be handled by
+	// EnsureLoadBalancer() that is the true LB reconcile function.
 
 	return nil
 }
@@ -2258,7 +2252,7 @@ func (lbaas *LbaasV2) ensureAndUpdateOctaviaSecurityGroup(clusterName string, ap
 	lbSecGroupID, err := secgroups.IDFromName(lbaas.network, lbSecGroupName)
 	if err != nil {
 		// If the security group of LB not exist, create it later
-		if isSecurityGroupNotFound(err) {
+		if cpoerrors.IsNotFound(err) {
 			lbSecGroupID = ""
 		} else {
 			return fmt.Errorf("error occurred finding security group: %s: %v", lbSecGroupName, err)
@@ -2558,11 +2552,10 @@ func (lbaas *LbaasV2) ensureLoadBalancerDeleted(ctx context.Context, clusterName
 		klog.InfoS("Updated load balancer tags", "lbID", loadbalancer.ID)
 	}
 
-	// Delete the Security Group
-	if lbaas.opts.ManageSecurityGroups {
-		if err := lbaas.EnsureSecurityGroupDeleted(clusterName, service); err != nil {
-			return err
-		}
+	// Delete the Security Group. We're doing that even if `manage-security-groups` is disabled to make sure we don't
+	// orphan created SGs even if CPO got reconfigured.
+	if err := lbaas.EnsureSecurityGroupDeleted(clusterName, service); err != nil {
+		return err
 	}
 
 	return nil
@@ -2574,7 +2567,7 @@ func (lbaas *LbaasV2) EnsureSecurityGroupDeleted(_ string, service *corev1.Servi
 	lbSecGroupName := getSecurityGroupName(service)
 	lbSecGroupID, err := secgroups.IDFromName(lbaas.network, lbSecGroupName)
 	if err != nil {
-		if isSecurityGroupNotFound(err) {
+		if cpoerrors.IsNotFound(err) {
 			// It is OK when the security group has been deleted by others.
 			return nil
 		}