-echo "Download image ubuntu-16.04-server-cloudimg-amd64-disk1.img ..."
-wget -q -nc http://artifacts.opnfv.org/sdnvpn/ubuntu-16.04-server-cloudimg-amd64-disk1.img -P ${DOVETAIL_CONFIG}
+ubuntu_image=${image_path}/ubuntu-16.04-server-cloudimg-amd64-disk1.img
+if [[ ! -f ${ubuntu_image} ]]; then
+ echo "Download image ubuntu-16.04-server-cloudimg-amd64-disk1.img ..."
+ wget -q -nc http://artifacts.opnfv.org/sdnvpn/ubuntu-16.04-server-cloudimg-amd64-disk1.img -P ${image_path}
+fi
+sudo cp ${ubuntu_image} ${DOVETAIL_CONFIG}