cinder Nexenta ISCSI Driver fails with "cinder.volume.manager SSLError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:579)"

Issue

• cinder Nexenta ISCSI Driver fails to initialise with below errors

2017-12-12 17:43:48.818 3218 INFO cinder.volume.manager [req-2026f77a-b8b0-4d9c-891e-67d04037343a - - - - -] Starting volume driver NexentaISCSIDriver (1.0.0)
2017-12-12 17:43:48.954 3218 ERROR cinder.volume.manager [req-2026f77a-b8b0-4d9c-891e-67d04037343a - - - - -] Failed to initialize driver.
2017-12-12 17:43:48.954 3218 ERROR cinder.volume.manager Traceback (most recent call last):
2017-12-12 17:43:48.954 3218 ERROR cinder.volume.manager   File "/usr/lib/python2.7/site-packages/cinder/volume/manager.py", line 414, in init_host
2017-12-12 17:43:48.954 3218 ERROR cinder.volume.manager     self.driver.do_setup(ctxt)
2017-12-12 17:43:48.954 3218 ERROR cinder.volume.manager   File "/usr/lib/python2.7/site-packages/cinder/volume/drivers/nexenta/ns5/iscsi.py", line 99, in do_setup
2017-12-12 17:43:48.954 3218 ERROR cinder.volume.manager     self.nef.post(url, data)
2017-12-12 17:43:48.954 3218 ERROR cinder.volume.manager   File "/usr/lib/python2.7/site-packages/cinder/volume/drivers/nexenta/ns5/jsonrpc.py", line 72, in __call__
2017-12-12 17:43:48.954 3218 ERROR cinder.volume.manager     resp = getattr(requests, self.method)(url, data=data, headers=headers)
2017-12-12 17:43:48.954 3218 ERROR cinder.volume.manager   File "/usr/lib/python2.7/site-packages/requests/api.py", line 111, in post
2017-12-12 17:43:48.954 3218 ERROR cinder.volume.manager     return request('post', url, data=data, json=json, **kwargs)
2017-12-12 17:43:48.954 3218 ERROR cinder.volume.manager   File "/usr/lib/python2.7/site-packages/requests/api.py", line 57, in request
2017-12-12 17:43:48.954 3218 ERROR cinder.volume.manager     return session.request(method=method, url=url, **kwargs)
2017-12-12 17:43:48.954 3218 ERROR cinder.volume.manager   File "/usr/lib/python2.7/site-packages/requests/sessions.py", line 475, in request
2017-12-12 17:43:48.954 3218 ERROR cinder.volume.manager     resp = self.send(prep, **send_kwargs)
2017-12-12 17:43:48.954 3218 ERROR cinder.volume.manager   File "/usr/lib/python2.7/site-packages/requests/sessions.py", line 585, in send
2017-12-12 17:43:48.954 3218 ERROR cinder.volume.manager     r = adapter.send(request, **kwargs)
2017-12-12 17:43:48.954 3218 ERROR cinder.volume.manager   File "/usr/lib/python2.7/site-packages/requests/adapters.py", line 477, in send
2017-12-12 17:43:48.954 3218 ERROR cinder.volume.manager     raise SSLError(e, request=request)
2017-12-12 17:43:48.954 3218 ERROR cinder.volume.manager SSLError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:579)