Ensure there is only one instance of LibvirtDriver

The HostState() class in libvirt creates a second instance of
the LibvirtDriver() class, which cause duplicate initialization
of various things. This is pointless, since it was a method on
the original LibvirtDriver() which created the HostState()
instance, and thus it could easily pass in the original object.

Blueprint: compute-driver-events
Change-Id: I0734bfcc1b014406ffe64ef7abb14a533998dea2
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

2 files changed, 4 insertions, 14 deletions

diff --git a/nova/tests/test_libvirt.py b/nova/tests/test_libvirt.py
index c93bb0168..d2cd5a757 100644
--- a/nova/tests/test_libvirt.py
+++ b/nova/tests/test_libvirt.py
@@ -3393,13 +3393,7 @@ class HostStateTestCase(test.TestCase):
             return HostStateTestCase.instance_caps
 
     def test_update_status(self):
-        virtapi = fake.FakeVirtAPI()
-        self.mox.StubOutWithMock(libvirt_driver, 'LibvirtDriver')
-        libvirt_driver.LibvirtDriver(virtapi, True).AndReturn(
-            self.FakeConnection())
-
-        self.mox.ReplayAll()
-        hs = libvirt_driver.HostState(virtapi, True)
+        hs = libvirt_driver.HostState(self.FakeConnection())
         stats = hs._stats
         self.assertEquals(stats["vcpus"], 1)
         self.assertEquals(stats["vcpus_used"], 0)
diff --git a/nova/virt/libvirt/driver.py b/nova/virt/libvirt/driver.py
index 4e2fb9d39..8ce03f13a 100755
--- a/nova/virt/libvirt/driver.py
+++ b/nova/virt/libvirt/driver.py
@@ -319,7 +319,7 @@ class LibvirtDriver(driver.ComputeDriver):
     @property
     def host_state(self):
         if not self._host_state:
-            self._host_state = HostState(self.virtapi, self.read_only)
+            self._host_state = HostState(self)
         return self._host_state
 
     def has_min_version(self, lv_ver=None, hv_ver=None, hv_type=None):
@@ -3306,12 +3306,10 @@ class LibvirtDriver(driver.ComputeDriver):
 
 class HostState(object):
     """Manages information about the compute node through libvirt."""
-    def __init__(self, virtapi, read_only):
+    def __init__(self, connection):
         super(HostState, self).__init__()
-        self.read_only = read_only
         self._stats = {}
-        self.connection = None
-        self.virtapi = virtapi
+        self.connection = connection
         self.update_status()
 
     def get_host_stats(self, refresh=False):
@@ -3325,8 +3323,6 @@ class HostState(object):
     def update_status(self):
         """Retrieve status info from libvirt."""
         LOG.debug(_("Updating host stats"))
-        if self.connection is None:
-            self.connection = LibvirtDriver(self.virtapi, self.read_only)
         data = {}
         data["vcpus"] = self.connection.get_vcpu_total()
         data["vcpus_used"] = self.connection.get_vcpu_used()