Configurable fixed network name

The fixed network gets his name when you use the:
nova-manage network create "$PRIVATE_NETWORK_NAME" $FIXED_RANGE 1 $FIXED_NETWORK_SIZE $NETWORK_CREATE_ARGS
command.

It can be different in every deployment, so it must be configurable.

Change-Id: I5c724565561b1a230372b8fc1693cb81fea3117e
diff --git a/etc/tempest.conf.sample b/etc/tempest.conf.sample
index b64b047..7920ab5 100644
--- a/etc/tempest.conf.sample
+++ b/etc/tempest.conf.sample
@@ -79,6 +79,9 @@
 # Name of a user used to authenticated to an instance
 ssh_user = cirros
 
+# Visible fixed network name
+fixed_network_name = private
+
 # Network id used for SSH (public, private, etc)
 network_for_ssh = private
 
diff --git a/tempest/config.py b/tempest/config.py
index a90767e..700489e 100644
--- a/tempest/config.py
+++ b/tempest/config.py
@@ -156,6 +156,9 @@
                default=60,
                help="Timeout in seconds to wait for output from ssh "
                     "channel."),
+    cfg.StrOpt('fixed_network_name',
+               default='private',
+               help="Visible fixed network name "),
     cfg.StrOpt('network_for_ssh',
                default='public',
                help="Network used for SSH connections."),
diff --git a/tempest/tests/compute/servers/test_list_server_filters.py b/tempest/tests/compute/servers/test_list_server_filters.py
index 852288e..ca5e112 100644
--- a/tempest/tests/compute/servers/test_list_server_filters.py
+++ b/tempest/tests/compute/servers/test_list_server_filters.py
@@ -75,6 +75,8 @@
         cls.client.wait_for_server_status(cls.s3['id'], 'ACTIVE')
         resp, cls.s3 = cls.client.get_server(cls.s3['id'])
 
+        cls.fixed_network_name = cls.config.compute.fixed_network_name
+
     @classmethod
     def tearDownClass(cls):
         cls.client.delete_server(cls.s1['id'])
@@ -208,7 +210,7 @@
     def test_list_servers_filtered_by_ip(self):
         # Filter servers by ip
         # Here should be listed 1 server
-        ip = self.s1['addresses']['private'][0]['addr']
+        ip = self.s1['addresses'][self.fixed_network_name][0]['addr']
         params = {'ip': ip}
         resp, body = self.client.list_servers(params)
         servers = body['servers']
@@ -222,7 +224,7 @@
         # Filter servers by regex ip
         # List all servers filtered by part of ip address.
         # Here should be listed all servers
-        ip = self.s1['addresses']['private'][0]['addr'][0:-3]
+        ip = self.s1['addresses'][self.fixed_network_name][0]['addr'][0:-3]
         params = {'ip': ip}
         resp, body = self.client.list_servers(params)
         servers = body['servers']