Fixes bug 723235

The XML templates have been converted into properties, thus we can
compare the mtime of the XML templates (libvirt and cpuinfo) each
time they are needed, checking if they have been modified and
reloading them. Added a function to read cached files.

Change-Id: I6cf0229c6435300e73f9d9a6b10b0bf9bf144a55

1 files changed, 16 insertions, 2 deletions

diff --git a/nova/virt/libvirt/connection.py b/nova/virt/libvirt/connection.py
index 5dee8f0c7..bbd45ee13 100644
--- a/nova/virt/libvirt/connection.py
+++ b/nova/virt/libvirt/connection.py
@@ -185,8 +185,6 @@ class LibvirtConnection(driver.ComputeDriver):
     def __init__(self, read_only):
         super(LibvirtConnection, self).__init__()
 
-        self.libvirt_xml = open(FLAGS.libvirt_xml_template).read()
-        self.cpuinfo_xml = open(FLAGS.cpuinfo_xml_template).read()
         self._host_state = None
         self._wrapped_conn = None
         self.read_only = read_only
@@ -220,6 +218,22 @@ class LibvirtConnection(driver.ComputeDriver):
         # NOTE(nsokolov): moved instance restarting to ComputeManager
         pass
 
+    @property
+    def libvirt_xml(self):
+        if not hasattr(self, '_libvirt_xml_cache_info'):
+            self._libvirt_xml_cache_info = {}
+
+        return utils.read_cached_file(FLAGS.libvirt_xml_template,
+                self._libvirt_xml_cache_info)
+
+    @property
+    def cpuinfo_xml(self):
+        if not hasattr(self, '_cpuinfo_xml_cache_info'):
+            self._cpuinfo_xml_cache_info = {}
+
+        return utils.read_cached_file(FLAGS.cpuinfo_xml_template,
+                self._cpuinfo_xml_cache_info)
+
     def _get_connection(self):
         if not self._wrapped_conn or not self._test_connection():
             LOG.debug(_('Connecting to libvirt: %s'), self.uri)