Unity: Attach Unity volume via IPv6.

The IPv6's ISCIS portal format is [IPv6Address]:Port.
The Unity returned IPv6 are not enclosed with brackets.
So Unity's cinder-driver has to add brackets for IPv6's ISCSI portal.

DocImpact
Change-Id: Ib54fe948d0f5d7cad6c28468503f8535573ef3fc
Implements: blueprint unity-cinder-ipv6

cinder/tests/unit/volume/drivers/dell_emc/unity/test_utils.py

@@ -168,6 +168,10 @@ class UnityUtilsTest(unittest.TestCase):
 
     def test_convert_ip_to_portal(self):
         self.assertEqual('1.2.3.4:3260', utils.convert_ip_to_portal('1.2.3.4'))
+        self.assertEqual('[fd27:2e95:e174::100]:3260',
+                         utils.convert_ip_to_portal('fd27:2e95:e174::100'))
+        self.assertEqual('[fd27:2e95:e174::100]:3260',
+                         utils.convert_ip_to_portal('[fd27:2e95:e174::100]'))
 
     def test_convert_to_itor_tgt_map(self):
         zone_mapping = {

cinder/volume/drivers/dell_emc/unity/driver.py

@@ -51,9 +51,10 @@ class UnityDriver(driver.ManageableVD,
     Version history:
         1.0.0 - Initial version
         2.0.0 - Add thin clone support
+        3.0.0 - Add IPv6 support
     """
 
-    VERSION = '02.00.00'
+    VERSION = '03.00.00'
     VENDOR = 'Dell EMC'
     # ThirdPartySystems wiki page
     CI_WIKI_NAME = "EMC_UNITY_CI"

cinder/volume/drivers/dell_emc/unity/utils.py

@@ -136,6 +136,9 @@ def extract_fc_uids(connector):
 
 
 def convert_ip_to_portal(ip):
+    is_ipv6_without_brackets = ':' in ip and ip[-1] != ']'
+    if is_ipv6_without_brackets:
+        return '[%s]:3260' % ip
     return '%s:3260' % ip
 
 

doc/source/configuration/block-storage/drivers/dell-emc-unity-driver.rst

@@ -275,6 +275,32 @@ not efficient since a cloned volume will be created during backup.
 An effective approach to backups is to create a snapshot for the volume and
 connect this snapshot to the Block Storage host for volume backup.
 
+IPv6 support
+~~~~~~~~~~~~
+
+This driver can support IPv6-based control path and data path.
+
+For control path, please follow below steps:
+
+- Enable Unity's Unipshere IPv6 address.
+- Configure the IPv6 network to make sure that cinder node can access Unishpere
+  via IPv6 address.
+- Change Cinder config file ``/etc/cinder/cinder.conf``. Make the ``san_ip``
+  as Unisphere IPv6 address. For example, ``san_ip = [fd99:f17b:37d0::100]``.
+- Restart the Cinder service to make new configuration take effect.
+
+**Note**: The IPv6 support on control path depends on the fix of cpython
+`bug 32185 <https://bugs.python.org/issue32185>`__. Please make sure your
+Python's version includes this bug's fix.
+
+For data path, please follow below steps:
+
+- On Unity, Create iSCSI interface with IPv6 address.
+- Configure the IPv6 network to make sure that you can ``ping``
+  the Unity's iSCSI IPv6 address from the Cinder node.
+- If you create a volume using Cinder and attach it to a VM,
+  the connection between this VM and volume will be IPv6-based iSCSI.
+
 Troubleshooting
 ~~~~~~~~~~~~~~~