Support hardware loopback for ixiatg

.github/linters/.golangci.yml

@@ -27,7 +27,6 @@ linters:
   enable:
     - gosec
     - unconvert
-    - goconst
     - goimports
     - gofmt
     - gocritic

topo/node/keysight/keysight.go

@@ -322,6 +322,12 @@ func (n *Node) FixInterfaces() {
 	}
 }
 
+func (n *Node) BackToBackLoop() bool {
+	// IxiaTG supports back to back loops due to the node implementation creating
+	// a pod per port.
+	return true
+}
+
 func defaults(pb *tpb.Node) *tpb.Node {
 	if pb.Services == nil {
 		pb.Services = map[uint32]*tpb.Service{

topo/node/node.go

@@ -58,6 +58,9 @@ type Implementation interface {
 	// Services provides a custom implementation for querying all services created for
 	// for a node. Requires context, Kubernetes client interface and namespace.
 	Services(context.Context) ([]*corev1.Service, error)
+	// BackToBackLoop returns a bool if the node supports links directly between
+	// two ports on the same node.
+	BackToBackLoop() bool
 }
 
 // Certer provides an interface for working with certs on nodes.
@@ -745,3 +748,9 @@ func (n *Impl) GetCLIConn(platform string, opts []scrapliutil.Option) (*scraplin
 		return d, nil
 	}
 }
+
+// BackToBackLoop returns a bool indicating if the node supports a single link
+// connecting two ports on the same node. By default this is false.
+func (n *Impl) BackToBackLoop() bool {
+	return false
+}

topo/topo.go

@@ -427,9 +427,6 @@ func (m *Manager) load() error {
 	uid := 0
 	for _, l := range m.topo.Links {
 		log.Infof("Adding Link: %s:%s %s:%s", l.ANode, l.AInt, l.ZNode, l.ZInt)
-		if l.ANode == l.ZNode {
-			return fmt.Errorf("invalid link: hardware loopback %s:%s %s:%s not supported", l.ANode, l.AInt, l.ZNode, l.ZInt)
-		}
 		aNode, ok := nMap[l.ANode]
 		if !ok {
 			return fmt.Errorf("invalid topology: missing node %q", l.ANode)
@@ -474,6 +471,14 @@ func (m *Manager) load() error {
 		}
 		m.nodes[k] = nn
 	}
+	for _, l := range m.topo.Links {
+		aNode := m.nodes[l.ANode]
+		zNode := m.nodes[l.ZNode]
+		loop := aNode.BackToBackLoop() && zNode.BackToBackLoop()
+		if !loop && l.ANode == l.ZNode {
+			return fmt.Errorf("invalid link: back to back loop %s:%s %s:%s not supported", l.ANode, l.AInt, l.ZNode, l.ZInt)
+		}
+	}
 	return nil
 }
 

topo/topo_test.go

@@ -93,6 +93,18 @@ func NewConfigurable(impl *node.Impl) (node.Node, error) {
 	return &configurable{Impl: impl}, nil
 }
 
+type loopbackable struct {
+	*node.Impl
+}
+
+func (l *loopbackable) BackToBackLoop() bool {
+	return true
+}
+
+func NewLoopbackable(impl *node.Impl) (node.Node, error) {
+	return &loopbackable{Impl: impl}, nil
+}
+
 type notConfigurable struct {
 	*node.Impl
 }
@@ -141,6 +153,7 @@ func (nc *notCertable) GetProto() *tpb.Node {
 
 func TestNew(t *testing.T) {
 	node.Vendor(tpb.Vendor(1001), NewConfigurable)
+	node.Vendor(tpb.Vendor(1006), NewLoopbackable)
 	tf, err := tfake.NewSimpleClientset()
 	if err != nil {
 		t.Fatalf("cannot create fake topology clientset: %v", err)
@@ -369,6 +382,30 @@ func TestNew(t *testing.T) {
 			},
 		},
 		wantErr: "invalid link",
+	}, {
+		desc: "loopback supported",
+		topo: &tpb.Topology{
+			Nodes: []*tpb.Node{
+				{
+					Name:   "r1",
+					Vendor: tpb.Vendor(1006),
+					Services: map[uint32]*tpb.Service{
+						1000: {
+							Name: "ssh",
+						},
+					},
+				},
+			},
+			Links: []*tpb.Link{
+				{
+					ANode: "r1",
+					AInt:  "eth1",
+					ZNode: "r1",
+					ZInt:  "eth2",
+				},
+			},
+		},
+		wantNodes: []string{"r1"},
 	}}
 	for _, tt := range tests {
 		t.Run(tt.desc, func(t *testing.T) {