Re-arrange getSubInterface() per review comments:

Check for trunks attached to VM interfaces only
Collapse two loop (trunks and subports) into one loop

Signed-off-by: Jing Zhang <jing.c.zhang@nokia.com>

Author: Jing Zhang

pkg/openstack/instances.go

@@ -735,68 +735,67 @@ func getAddressesByName(compute *gophercloud.ServiceClient, name types.NodeName,
 	return nodeAddresses(&srv.Server, interfaces, networkingOpts)
 }
 
-// getSubInterfaces
-func getSubInterfaces(network *gophercloud.ServiceClient) ([]attachinterfaces.Interface, error) {
-	var interfaces []attachinterfaces.Interface
-
-	// Check if trunk ports are attached
-	listOpts := trunks.ListOpts{}
-	allPages, err := trunks.List(network, listOpts).AllPages()
-	if err != nil {
-		klog.Errorf("Failed to list trunks: %v", err)
-		return interfaces, err
-	}
-	allTrunks, err := trunks.ExtractTrunks(allPages)
-	if err != nil {
-		klog.Errorf("Failed to extract trunks: %v", err)
-		return interfaces, err
-	}
+// getSubInterfaces returns the sub-interfaces attached via trunks to the specified node interfaces
+func getSubInterfaces(interfaces []attachinterfaces.Interface, network *gophercloud.ServiceClient) ([]attachinterfaces.Interface, error) {
+	klog.V(5).Infof("Node has %d interfaces '%v'", len(interfaces), interfaces)
 
-	// Get subports attached to the trunk
-	var subports []trunks.Subport
-	for _, trunk := range allTrunks {
-		for _, iface := range interfaces {
-			if iface.PortID == trunk.PortID {
-				s, err := trunks.GetSubports(network, trunk.ID).Extract()
-				if err != nil {
-					klog.Errorf("Failed to get subports for trunk %s: %v", trunk.ID, err)
-					return interfaces, err
-				}
-				subports = append(subports, s...)
-			}
+	for _, iface := range interfaces {
+		// Check if trunk ports are attached
+		listOpts := trunks.ListOpts{
+			PortID: iface.PortID,
 		}
-	}
-	klog.V(5).Infof("subports %v", subports)
-
-	// Arrange subports as for directly attached ports
-	for _, sport := range subports {
-		p, err := ports.Get(network, sport.PortID).Extract()
+		allPages, err := trunks.List(network, listOpts).AllPages()
 		if err != nil {
-			klog.Errorf("Failed to get port info for subport %s: %v", sport.PortID, err)
+			klog.Errorf("Failed to list trunks: %v", err)
 			return interfaces, err
 		}
-		n, err := networks.Get(network, p.NetworkID).Extract()
+		allTrunks, err := trunks.ExtractTrunks(allPages)
 		if err != nil {
-			klog.Errorf("Failed to get network info for subport %s: %v", sport.PortID, err)
+			klog.Errorf("Failed to extract trunks: %v", err)
 			return interfaces, err
 		}
-		var iface = attachinterfaces.Interface{
-			PortState: "ACTIVE",
-			FixedIPs:  []attachinterfaces.FixedIP{},
-			PortID:    p.ID,
-			NetID:     n.Name,
-			MACAddr:   p.MACAddress,
-		}
-		for _, ip := range p.FixedIPs {
-			var ip2 = attachinterfaces.FixedIP{
-				SubnetID:  ip.SubnetID,
-				IPAddress: ip.IPAddress,
+		// Get subports attached to the trunks
+		for _, trunk := range allTrunks {
+			subports, err := trunks.GetSubports(network, trunk.ID).Extract()
+			if err != nil {
+				klog.Errorf("Failed to get subports for trunk %s: %v", trunk.ID, err)
+				return interfaces, err
+			}
+			if len(subports) == 0 {
+				continue
+			}
+			klog.V(5).Infof("Subports for trunk %s: %v", trunk.ID, subports)
+			// Arrange subports as for directly attached ports
+			for _, sport := range subports {
+				p, err := ports.Get(network, sport.PortID).Extract()
+				if err != nil {
+					klog.Errorf("Failed to get port info for subport %s: %v", sport.PortID, err)
+					return interfaces, err
+				}
+				n, err := networks.Get(network, p.NetworkID).Extract()
+				if err != nil {
+					klog.Errorf("Failed to get network info for subport %s: %v", sport.PortID, err)
+					return interfaces, err
+				}
+				var iface = attachinterfaces.Interface{
+					PortState: "ACTIVE",
+					FixedIPs:  []attachinterfaces.FixedIP{},
+					PortID:    p.ID,
+					NetID:     n.Name,
+					MACAddr:   p.MACAddress,
+				}
+				for _, ip := range p.FixedIPs {
+					var ip2 = attachinterfaces.FixedIP{
+						SubnetID:  ip.SubnetID,
+						IPAddress: ip.IPAddress,
+					}
+					iface.FixedIPs = append(iface.FixedIPs, ip2)
+				}
+				interfaces = append(interfaces, iface)
 			}
-			iface.FixedIPs = append(iface.FixedIPs, ip2)
 		}
-		interfaces = append(interfaces, iface)
 	}
-	klog.V(5).Infof("interfaces %v", interfaces)
+	klog.V(5).Infof("Node has %d interfaces including subports '%v'", len(interfaces), interfaces)
 	return interfaces, nil
 }
 
@@ -817,7 +816,7 @@ func getAttachedInterfacesByID(compute *gophercloud.ServiceClient, serviceID str
 	if mc.ObserveRequest(err) != nil {
 		return interfaces, err
 	}
-	subInterfaces, err := getSubInterfaces(network)
+	subInterfaces, err := getSubInterfaces(interfaces, network)
 	if err != nil {
 		return interfaces, err
 	}