1- Need to know the API version ( http://172.30.54.71:8774/v2/ )
2- Openstack API listen on port 8774 ( http://<IP@>:8774 )
https://docs.openstack.org/juno/config-reference/content/list-of-compute-config-options.html
Default option: osapi_compute_listen_port = 8774
root@vse2100-11:~# more /etc/nova/nova.conf | grep port
rabbit_port=5672
report_interval=10
novncproxy_port=5999
auth_port=35357
