Raise exception when no IPs found

When generating the inventory, an exception is now raised if no IP
addresses are found for a given role from the specified network.
Previously, an unhandled IndexError was thrown with no indication as to
the actual problem.

This situtation can occur when using pre-provisioned nodes and a
malformed DeployedServerPortMap value such that no IP addresses are
assigned.

Change-Id: I2615bf4d5fcedbcf85d11e4aedbe22061348ded2

tripleo_common/inventory.py

@@ -222,6 +222,9 @@ class TripleoInventory(object):
                 shortnames = [n.split(".%s." % self.host_network)[0].lower()
                               for n in names]
                 ips = role_net_ip_map[role][self.host_network]
+                if not ips:
+                    raise Exception("No IPs found for %s role on %s network"
+                                    % (role, self.host_network))
                 hosts = {}
                 for idx, name in enumerate(shortnames):
                     hosts[name] = {}

tripleo_common/tests/test_inventory.py

@@ -158,6 +158,12 @@ class TestInventory(base.TestCase):
         self.assertTrue(self.hclient.called_once_with('overcloud',
                                                       'KeystoneURL'))
 
+    def test_no_ips(self):
+        for output in self.outputs_data['outputs']:
+            if output['output_key'] == 'RoleNetIpMap':
+                output['output_value'] = dict(Controller=dict(ctlplane=[]))
+        self.assertRaises(Exception, self.inventory.list)
+
     def test_outputs_invalid_key_raises_keyerror(self):
         self.assertRaises(KeyError, lambda: self.outputs['Invalid'])