Add rbd tests

drivers/storage/rbd/executor/rbd_executor.go

@@ -94,11 +94,13 @@ func (d *driver) InstanceID(
 	ctx types.Context,
 	opts types.Store) (*types.InstanceID, error) {
 
-	return GetInstanceID()
+	return GetInstanceID(nil, nil)
 }
 
 // GetInstanceID returns the instance ID object
-func GetInstanceID() (*types.InstanceID, error) {
+func GetInstanceID(
+	monIPs []net.IP,
+	localIntfs []net.Addr) (*types.InstanceID, error) {
 	/* Ceph doesn't have only one unique identifier per client, it can have
 	   several. With the way the RBD driver is used, we will see multiple
 	   identifiers used, and therefore returning any of those identifiers
@@ -110,17 +112,22 @@ func GetInstanceID() (*types.InstanceID, error) {
 	   segment so we grab the IP from the default route.
 	*/
 
-	monIPs, err := getCephMonIPs()
-	if err != nil {
-		return nil, err
+	var err error
+	if nil == monIPs {
+		monIPs, err = getCephMonIPs()
+		if err != nil {
+			return nil, err
+		}
 	}
 	if len(monIPs) == 0 {
 		return nil, goof.New("No Ceph Monitors found")
 	}
 
-	localIntfs, err := net.InterfaceAddrs()
-	if err != nil {
-		return nil, err
+	if nil == localIntfs {
+		localIntfs, err = net.InterfaceAddrs()
+		if err != nil {
+			return nil, err
+		}
 	}
 
 	iid := &types.InstanceID{Driver: rbd.Name}
@@ -135,7 +142,7 @@ func GetInstanceID() (*types.InstanceID, error) {
 		}
 	}
 
-	// No luck finding L2 match, use default gateway
+	// No luck finding L2 match, check for default/static route to monitor
 	localIP, err := getSrcIP(monIPs[0].String())
 	if err != nil {
 		return nil, err