Refactor Ubuntu image stack

So far users could name the Ubuntu interface in any way they wanted.

The ability to name Ubuntu interface allowed tobiko to run tests
successfully for each OSP version, but it required changing it every
time a different version is being run.

This issue was fixed by setting the Ubuntu interface name in the tobiko
code.

This patch removes the unnecessary remaining parts.

Change-Id: I0fcb4b9086bf8bbae5d98983971650a2244e52a1

infrared_plugin/plugin.spec

@@ -153,10 +153,6 @@ subparsers:
             type: Value
             help: user name to be used to connect to TripleO Overcloud hosts
             ansible_variable: overcloud_ssh_username
-          ubuntu-interface-name:
-            type: Value
-            help: primary interface name obtained from the ubuntu instances
-            ansible_variable: ubuntu_interface_name
 
       - title: Run stage
         options:

roles/tobiko-configure/defaults/main.yaml

@@ -13,8 +13,6 @@ test_default_conf:
   tripleo:
     undercloud_ssh_hostname: "{{ undercloud_ssh_hostname }}"
     overcloud_ssh_username: "{{ overcloud_ssh_username }}"
-  ubuntu:
-    interface_name:  "{{ ubuntu_interface_name }}"
 
 test_log_debug: ''
 
@@ -28,5 +26,3 @@ undercloud_hostname: '{{ groups.get("undercloud", []) | first | default("undercl
 undercloud_ssh_hostname: ''
 
 overcloud_ssh_username: ''
-
-ubuntu_interface_name: ''

tobiko/openstack/glance/config.py

@@ -62,8 +62,6 @@ def get_images_options():
                         help="Default " + name + " username"),
              cfg.StrOpt('password',
                         help="Default " + name + " password"),
-             cfg.StrOpt('interface_name',
-                        help="Default " + name + " image interface name"),
              cfg.FloatOpt('connection_timeout',
                           default=None,
                           help=("Default " + name +

tobiko/openstack/stacks/_ubuntu.py

@@ -132,14 +132,14 @@ class UbuntuImageFixture(UbuntuMinimalImageFixture,
 
     @staticmethod
     def _get_ethernet_device() -> str:
-        ethernet_device = CONF.tobiko.ubuntu.interface_name
-        if ethernet_device is None:
-            from tobiko import tripleo
-            if tripleo.has_overcloud(min_version='17.0'):
-                ethernet_device = 'enp3s0'
-            else:
-                ethernet_device = 'ens3'
-        return ethernet_device
+        """From OSP17 and above, Ubuntu stack should use a different interface name.
+        This method returns the interface name, depending on the OSP version.
+        """
+        from tobiko import tripleo
+        if tripleo.has_overcloud(min_version='17.0'):
+            return 'enp3s0'
+        else:
+            return 'ens3'
 
     def _get_customized_suffix(self) -> str:
         return f'{super()._get_customized_suffix()}-{self.ethernet_device}'