Support launch instance on external provider network

Allow launching an instance and attaching it directly to the
external provider network.  This is useful in its own right and
is also a requirement in order to successfully test some
configurations.

(cherry picked from commit 3ec6470)

zaza/openstack/charm_tests/test_utils.py

@@ -751,7 +751,8 @@ def resource_cleanup(self):
             pass
 
     def launch_guest(self, guest_name, userdata=None, use_boot_volume=False,
-                     instance_key=None, flavor_name=None):
+                     instance_key=None, flavor_name=None,
+                     attach_to_external_network=False):
         """Launch one guest to use in tests.
 
         Note that it is up to the caller to have set the RESOURCE_PREFIX class
@@ -768,6 +769,9 @@ def launch_guest(self, guest_name, userdata=None, use_boot_volume=False,
         :type use_boot_volume: boolean
         :param instance_key: Key to collect associated config data with.
         :type instance_key: Optional[str]
+        :param attach_to_external_network: Attach instance directly to external
+                                           network.
+        :type attach_to_external_network: bool
         :returns: Nova instance objects
         :rtype: Server
         """
@@ -796,7 +800,8 @@ def launch_guest(self, guest_name, userdata=None, use_boot_volume=False,
                     vm_name=instance_name,
                     use_boot_volume=use_boot_volume,
                     userdata=userdata,
-                    flavor_name=flavor_name)
+                    flavor_name=flavor_name,
+                    attach_to_external_network=attach_to_external_network)
 
     def launch_guests(self, userdata=None, attach_to_external_network=False,
                       flavor_name=None):
@@ -807,6 +812,9 @@ def launch_guests(self, userdata=None, attach_to_external_network=False,
 
         :param userdata: Userdata to attach to instance
         :type userdata: Optional[str]
+        :param attach_to_external_network: Attach instance directly to external
+                                           network.
+        :type attach_to_external_network: bool
         :returns: List of launched Nova instance objects
         :rtype: List[Server]
         """

zaza/openstack/configure/guest.py

@@ -53,7 +53,7 @@
 def launch_instance(instance_key, use_boot_volume=False, vm_name=None,
                     private_network_name=None, image_name=None,
                     flavor_name=None, external_network_name=None, meta=None,
-                    userdata=None):
+                    userdata=None, attach_to_external_network=False):
     """Launch an instance.
 
     :param instance_key: Key to collect associated config data with.
@@ -76,6 +76,9 @@ def launch_instance(instance_key, use_boot_volume=False, vm_name=None,
     :type meta: dict
     :param userdata: Configuration to use upon launch, used by cloud-init.
     :type userdata: str
+    :param attach_to_external_network: Attach instance directly to external
+                                       network.
+    :type attach_to_external_network: bool
     :returns: the created instance
     :rtype: novaclient.Server
     """
@@ -94,12 +97,18 @@ def launch_instance(instance_key, use_boot_volume=False, vm_name=None,
     flavor = nova_client.flavors.find(name=flavor_name)
 
     private_network_name = private_network_name or "private"
-    net = neutron_client.find_resource("network", private_network_name)
-    nics = [{'net-id': net.get('id')}]
 
     meta = meta or {}
     external_network_name = external_network_name or "ext_net"
 
+    if attach_to_external_network:
+        instance_network_name = external_network_name
+    else:
+        instance_network_name = private_network_name
+
+    net = neutron_client.find_resource("network", instance_network_name)
+    nics = [{'net-id': net.get('id')}]
+
     if use_boot_volume:
         bdmv2 = [{
             'boot_index': '0',
@@ -143,12 +152,19 @@ def launch_instance(instance_key, use_boot_volume=False, vm_name=None,
     port = openstack_utils.get_ports_from_device_id(
         neutron_client,
         instance.id)[0]
-    logging.info('Assigning floating ip.')
-    ip = openstack_utils.create_floating_ip(
-        neutron_client,
-        external_network_name,
-        port=port)['floating_ip_address']
-    logging.info('Assigned floating IP {} to {}'.format(ip, vm_name))
+    if attach_to_external_network:
+        logging.info('attach_to_external_network={}, not assigning floating IP'
+                     .format(attach_to_external_network))
+        ip = port['fixed_ips'][0]['ip_address']
+        logging.info('Using fixed IP {} on network {} for {}'
+                     .format(ip, instance_network_name, vm_name))
+    else:
+        logging.info('Assigning floating ip.')
+        ip = openstack_utils.create_floating_ip(
+            neutron_client,
+            external_network_name,
+            port=port)['floating_ip_address']
+        logging.info('Assigned floating IP {} to {}'.format(ip, vm_name))
     try:
         for attempt in Retrying(
                 stop=stop_after_attempt(8),