Add util for disk type retrieval

blueprint snapshots-for-everyone

Add libvirt.utils.get_disk_type that retrieves format
for given file. Format can be raw, qcow2, or lvm.

Change-Id: I33898983cfa15db6b2654648ce32f72b6dd920cb

nova/tests/fake_libvirt_utils.py

@@ -21,6 +21,7 @@ import StringIO
 files = {}
 disk_sizes = {}
 disk_backing_files = {}
+disk_type = "qcow2"
 
 
 def get_iscsi_initiator():
@@ -39,6 +40,10 @@ def get_disk_backing_file(path):
     return disk_backing_files.get(path, None)
 
 
+def get_disk_type(path):
+    return disk_type
+
+
 def copy_image(src, dest):
     pass
 

nova/tests/test_libvirt.py

@@ -1162,6 +1162,7 @@ class LibvirtConnTestCase(test.TestCase):
         libvirt_driver.LibvirtDriver._conn.lookupByName = self.fake_lookup
         self.mox.StubOutWithMock(libvirt_driver.utils, 'execute')
         libvirt_driver.utils.execute = self.fake_execute
+        self.stubs.Set(libvirt_driver.libvirt_utils, 'disk_type', 'raw')
 
         self.mox.ReplayAll()