Huawei: disable certificate verification

Globally disable verification by monkeypatching the ssl
module in version of Python that enable certificate verification
by default for stdlib http clients.

Change-Id: If672933e581f06ffcd4c8d64921d061f42de23dc
Closes-Bug: #1672288

cinder/volume/drivers/huawei/rest_client.py

@@ -17,6 +17,7 @@ import json
 import re
 import six
 import socket
+import ssl
 import time
 
 from oslo_log import log as logging
@@ -72,6 +73,14 @@ class RestClient(object):
         opener = urllib.request.build_opener(handler)
         urllib.request.install_opener(opener)
         res_json = None
+        try:
+            create_unverified_https_context = ssl._create_unverified_context
+        except AttributeError:
+            # Legacy Python that doesn't verify HTTPS certificates by default
+            pass
+        else:
+            # Handle target environment that doesn't support HTTPS verification
+            ssl._create_default_https_context = create_unverified_https_context
 
         try:
             socket.setdefaulttimeout(calltimeout)

releasenotes/notes/globally-disble-verification-6354b916c0c47918.yaml

@@ -0,0 +1,3 @@
+---
+fixes:
+   SSL certificate validation is now disabled for the Huawei driver.