add a fallback to an ipv4 address if the the range can't find one

builder/vsphere/common/step_http_ip_discover.go

@@ -43,6 +43,7 @@ func getHostIP(s string, network *net.IPNet) (string, error) {
 		return "", err
 	}
 
+	// look for an IP that is contained in the ip_wait_address range
 	for _, a := range addrs {
 		ipnet, ok := a.(*net.IPNet)
 		if ok && !ipnet.IP.IsLoopback() {
@@ -51,5 +52,15 @@ func getHostIP(s string, network *net.IPNet) (string, error) {
 			}
 		}
 	}
+
+	// fallback to an ipv4 address if an IP is not found in the range
+	for _, a := range addrs {
+		ipnet, ok := a.(*net.IPNet)
+		if ok && !ipnet.IP.IsLoopback() {
+			if ipnet.IP.To4() != nil {
+				return ipnet.IP.String(), nil
+			}
+		}
+	}
 	return "", fmt.Errorf("IP not found")
 }