From: Josep Puigdemont <josep.puigdemont@enea.com>
Date: Wed, 4 May 2016 14:27:23 +0200
Subject: [PATCH] virtual_fuel: add XML tree as attribute of VirtualFuel

Now the VM XML definition tree is an attribute of the object, this way
it can be used by all methods without having to re-read the file from
the file.

Methods added:
update_vm_template_file: Flushes the contents of the in-memory XML
    representation of the VM to the backing file.

del_vm_nics: Deletes all interfaces from the VM

add_vm_nic: Adds a new NIC to the VM, it now takes the name of the
    bridge as a parameter.

Add a function to flush the contents of the in-memory XML representation
to the file update_vm_template_file

Signed-off-by: Josep Puigdemont <josep.puigdemont@enea.com>
---
 deploy/environments/virtual_fuel.py | 37 +++++++++++++++++++++++++------------
 1 file changed, 25 insertions(+), 12 deletions(-)

diff --git a/deploy/environments/virtual_fuel.py b/deploy/environments/virtual_fuel.py
index 92a234c..b68577e 100644
--- a/deploy/environments/virtual_fuel.py
+++ b/deploy/environments/virtual_fuel.py
@@ -13,6 +13,7 @@ from execution_environment import ExecutionEnvironment
 import tempfile
 import os
 import re
+import time
 
 from common import (
     exec_cmd,
@@ -50,28 +51,38 @@ class VirtualFuel(ExecutionEnvironment):
                                       self.dha.get_node_property(
                                           self.fuel_node_id, 'libvirtTemplate'))
         check_file_exists(self.vm_template)
+        with open(self.vm_template) as f:
+            self.vm_xml = etree.parse(f)
+
+        self.temp_vm_file = '%s/%s' % (self.temp_dir, self.vm_name)
+        self.update_vm_template_file()
 
     def __del__(self):
         delete(self.temp_dir)
 
-    def set_vm_nic(self, temp_vm_file):
-        with open(temp_vm_file) as f:
-            vm_xml = etree.parse(f)
-        interfaces = vm_xml.xpath('/domain/devices/interface')
+    def update_vm_template_file(self):
+        with open(self.temp_vm_file, "wc") as f:
+            self.vm_xml.write(f, pretty_print=True, xml_declaration=True)
+
+    def del_vm_nics(self):
+        interfaces = self.vm_xml.xpath('/domain/devices/interface')
         for interface in interfaces:
             interface.getparent().remove(interface)
+
+    def add_vm_nic(self, bridge):
         interface = etree.Element('interface')
         interface.set('type', 'bridge')
         source = etree.SubElement(interface, 'source')
-        source.set('bridge', self.pxe_bridge)
+        source.set('bridge', bridge)
         model = etree.SubElement(interface, 'model')
         model.set('type', 'virtio')
-        devices = vm_xml.xpath('/domain/devices')
+
+        devices = self.vm_xml.xpath('/domain/devices')
         if devices:
             device = devices[0]
             device.append(interface)
-        with open(temp_vm_file, 'w') as f:
-            vm_xml.write(f, pretty_print=True, xml_declaration=True)
+        else:
+            err('No devices!')
 
     def create_volume(self, pool, name, su, img_type='qcow2'):
         log('Creating image using Libvirt volumes in pool %s, name: %s' %
@@ -109,11 +120,13 @@ class VirtualFuel(ExecutionEnvironment):
         disk_size = disk_sizes['fuel']
         disk_path = self.create_image(disk_path, disk_size)
 
-        temp_vm_file = '%s/%s' % (self.temp_dir, self.vm_name)
-        exec_cmd('cp %s %s' % (self.vm_template, temp_vm_file))
-        self.set_vm_nic(temp_vm_file)
+        self.del_vm_nics()
+        self.add_vm_nic(self.pxe_bridge)
+        self.update_vm_template_file()
+
         vm_definition_overwrite = self.dha.get_vm_definition('fuel')
-        self.define_vm(self.vm_name, temp_vm_file, disk_path,
+
+        self.define_vm(self.vm_name, self.temp_vm_file, disk_path,
                        vm_definition_overwrite)
 
     def setup_environment(self):