Bug #898290: iSCSI volume backend treats FLAGS.host as a hostname

Change ISCSIDriver to set volume.provider_location during create_export.
This records the location of the LUN, so that nova-compute does not need
to run the iSCSI discovery code itself.

As part of this, include the IP address of the target (--iscsi_ip_address) in
the provider_location.  This means that we don't use volume's host identifier
(which could be an opaque ID) when trying to connect to the iSCSI target --
we use the admin-specified IP address instead.

The string-join to set provider_location is shared with ZadaraBEDriver,
which was doing something similar.  I've brought that into a helper function.

The docstring for the --host flag has been clarified.

Change-Id: I8402da86345e786a46a4d222ad4d8a4449d2bd3f

2 files changed, 15 insertions, 5 deletions

diff --git a/nova/flags.py b/nova/flags.py
index c47c77ab1..e0f1ceded 100644
--- a/nova/flags.py
+++ b/nova/flags.py
@@ -440,7 +440,8 @@ DEFINE_string('image_service', 'nova.image.glance.GlanceImageService',
               'The service to use for retrieving and searching for images.')
 
 DEFINE_string('host', socket.gethostname(),
-              'name of this node')
+              'Name of this node.  This can be an opaque identifier.  It is '
+              'not necessarily a hostname, FQDN, or IP address.')
 
 DEFINE_string('node_availability_zone', 'nova',
               'availability zone of this node')
diff --git a/nova/volume/driver.py b/nova/volume/driver.py
index 893691669..86161d068 100644
--- a/nova/volume/driver.py
+++ b/nova/volume/driver.py
@@ -47,6 +47,8 @@ flags.DEFINE_string('iscsi_target_prefix', 'iqn.2010-10.org.openstack:',
                     'prefix for iscsi volumes')
 flags.DEFINE_string('iscsi_ip_address', '$my_ip',
                     'use this ip for iscsi')
+flags.DEFINE_integer('iscsi_port', 3260,
+                     'The port that the iSCSI daemon is listening on')
 flags.DEFINE_string('rbd_pool', 'rbd',
                     'the rbd pool in which volumes are stored')
 
@@ -279,6 +281,11 @@ class ISCSIDriver(VolumeDriver):
         self.tgtadm.new_target(iscsi_name, iscsi_target)
         self.tgtadm.new_logicalunit(iscsi_target, 0, volume_path)
 
+        model_update = {}
+        model_update['provider_location'] = _iscsi_location(
+            FLAGS.iscsi_ip_address, iscsi_target, iscsi_name)
+        return model_update
+
     def remove_export(self, context, volume):
         """Removes an export for a logical volume."""
         try:
@@ -923,12 +930,10 @@ class ZadaraBEDriver(ISCSIDriver):
 
         sn_ip = response_node.findtext("SnIp")
         sn_iqn = response_node.findtext("IqnName")
-        iscsi_portal = sn_ip + ":3260," + ("%s" % iscsi_target)
 
         model_update = {}
-        model_update['provider_location'] = ("%s %s" %
-                                             (iscsi_portal,
-                                              sn_iqn))
+        model_update['provider_location'] = _iscsi_location(
+            sn_ip, iscsi_target, sn_iqn)
         return model_update
 
     def _get_qosgroup_summary(self):
@@ -977,3 +982,7 @@ class ZadaraBEDriver(ISCSIDriver):
 
         drive_info = self._get_qosgroup_summary()
         return {'drive_qos_info': drive_info}
+
+
+def _iscsi_location(ip, target, iqn):
+    return "%s:%s,%s %s" % (ip, FLAGS.iscsi_port, target, iqn)