Comment 15 for bug 1833160

Hey, Ryan! I've tested this script you created in my environment and I had the same problem you're facing. The stacktrace I got while running the script is:

... resp = opener.open(req)
Traceback (most recent call last):
  File "<stdin>", line 2, in <module>
  File "/usr/lib/python3.7/urllib/request.py", line 525, in open
    response = self._open(req, data)
  File "/usr/lib/python3.7/urllib/request.py", line 543, in _open
    '_open', req)
  File "/usr/lib/python3.7/urllib/request.py", line 503, in _call_chain
    result = func(*args)
  File "/usr/lib/python3.7/urllib/request.py", line 1360, in https_open
    context=self._context, check_hostname=self._check_hostname)
  File "/usr/lib/python3.7/urllib/request.py", line 1317, in do_open
    encode_chunked=req.has_header('Transfer-encoding'))
  File "/usr/lib/python3.7/http/client.py", line 1229, in request
    self._send_request(method, url, body, headers, encode_chunked)
  File "/usr/lib/python3.7/http/client.py", line 1275, in _send_request
    self.endheaders(body, encode_chunked=encode_chunked)
  File "/usr/lib/python3.7/http/client.py", line 1224, in endheaders
    self._send_output(message_body, encode_chunked=encode_chunked)
  File "/usr/lib/python3.7/http/client.py", line 1016, in _send_output
    self.send(msg)
  File "/usr/lib/python3.7/http/client.py", line 956, in send
    self.connect()
  File "/usr/lib/python3.7/http/client.py", line 1392, in connect
    server_hostname=server_hostname)
  File "/usr/local/lib/python3.7/dist-packages/eventlet/green/ssl.py", line 438, in wrap_socket
    return GreenSSLSocket(sock, *a, _context=self, **kw)
  File "/usr/local/lib/python3.7/dist-packages/eventlet/green/ssl.py", line 76, in __new__
    *args, **kw
TypeError: wrap_socket() got an unexpected keyword argument '_context'
>>> print(resp)

I've looked how the NetApp driver works it around since I'm using the same library versions you're using and the driver is not breaking. I didn't found things that are strongly different.
I've added a log to show as a dict the created request object. Here is my output:

{'_full_url': 'http://x.x.x.x:80/servlets/netapp.servlets.admin.XMLrequest_filer', 'fragment': None, 'type': 'http', 'host': 'x.x.x.x:80', 'selector': '/servlets/netapp.servlets.admin.XMLrequest_filer', 'headers': {'Content-type': 'text/xml', 'Charset': 'utf-8'}, 'unredirected_hdrs': {}, '_data': b'<netapp xmlns="http://www.netapp.com/filer/admin" version="1.140"><perf-object-counter-list-info><objectname>processor</objectname></perf-object-counter-list-info></netapp>', '_tunnel_host': None, 'origin_req_host': 'x.x.x.x', 'unverifiable': False}

You can see if there is something different.
Also, does the VNX driver mounts the request url with a port?
You can take a look in the way NetApp driver does it [1]. There are few different things I've realized while comparing the way each driver create the requests. I think you're very close to figure out a solution to this problem.
[1] https://github.com/openstack/manila/blob/master/manila/share/drivers/netapp/dataontap/client/api.py#L230