VMAX Target iSCSI IP Address

VMAX Target iSCSI IP Address

In VMAX iSCSI driver, the iscsi_ip_address was hardcoded
in cinder.conf. This may have issues with multi-portgroup
environment. If a customer has multiple portgroups
containing different ports with different iSCSI IP addresses,
then ‘iscsiadm‘ command cannot use more than the one hardcoded
IP address in its sendtargets operation.

This patch addresses this by examining the ports in the
portgroup of the masking view used in the attach operation.
Each port has a corresponding iSCSI IP address. A portgroup
with only one port will have one IP address; a portgroup with
multiple ports will have multiple IP addresses. Even if there
is more than one IP address, the first in the list is likely to
result in a successful iscsiadm -sendtargets.

Closes-Bug: #1501678
Change-Id: I52ab6b278a114d55aec5e66b38ff76fd1bfb1b49