Don't import libvirt_utils in disk api.

Updates the virt/disk/api so that we no longer import libvirt_utils.

This fixes issues when using Nova compute with compute drivers other
than libvirt. (xenapi, etc.)

Fixes LP Bug #1029501.

Change-Id: I46ece309480ce0a0941a96371a51d77712c41eb6

nova/tests/fake_libvirt_utils.py

@@ -35,10 +35,6 @@ def create_cow_image(backing_file, path):
     pass
 
 
-def get_disk_size(path):
-    return disk_sizes.get(path, 1024 * 1024 * 20)
-
-
 def get_disk_backing_file(path):
     return disk_backing_files.get(path, None)
 

nova/tests/test_imagebackend.py

@@ -238,7 +238,7 @@ class LvmTestCase(_ImageTestCase):
         fn = self.mox.CreateMockAnything()
         self.mox.StubOutWithMock(self.disk, 'resize2fs')
         self.mox.StubOutWithMock(self.libvirt_utils, 'create_lvm_image')
-        self.mox.StubOutWithMock(self.libvirt_utils, 'get_disk_size')
+        self.mox.StubOutWithMock(self.disk, 'get_disk_size')
         self.mox.StubOutWithMock(self.utils, 'execute')
         return fn
 
@@ -249,7 +249,7 @@ class LvmTestCase(_ImageTestCase):
                                             self.LV,
                                             self.TEMPLATE_SIZE,
                                             sparse=sparse)
-        self.libvirt_utils.get_disk_size(self.TEMPLATE_PATH
+        self.disk.get_disk_size(self.TEMPLATE_PATH
                                          ).AndReturn(self.TEMPLATE_SIZE)
         cmd = ('dd', 'if=%s' % self.TEMPLATE_PATH,
                'of=%s' % self.PATH, 'bs=4M')
@@ -279,7 +279,7 @@ class LvmTestCase(_ImageTestCase):
         fn(target=self.TEMPLATE_PATH)
         self.libvirt_utils.create_lvm_image(self.VG, self.LV,
                                             self.SIZE, sparse=sparse)
-        self.libvirt_utils.get_disk_size(self.TEMPLATE_PATH
+        self.disk.get_disk_size(self.TEMPLATE_PATH
                                          ).AndReturn(self.TEMPLATE_SIZE)
         cmd = ('dd', 'if=%s' % self.TEMPLATE_PATH,
                'of=%s' % self.PATH, 'bs=4M')
@@ -321,7 +321,7 @@ class LvmTestCase(_ImageTestCase):
                                             self.SIZE,
                                             sparse=False
                                             ).AndRaise(RuntimeError())
-        self.libvirt_utils.get_disk_size(self.TEMPLATE_PATH
+        self.disk.get_disk_size(self.TEMPLATE_PATH
                                          ).AndReturn(self.TEMPLATE_SIZE)
         self.mox.StubOutWithMock(self.libvirt_utils, 'remove_logical_volumes')
         self.libvirt_utils.remove_logical_volumes(self.PATH)

nova/tests/test_libvirt.py

@@ -46,6 +46,7 @@ from nova.tests import fake_libvirt_utils
 from nova.tests import fake_network
 import nova.tests.image.fake
 from nova import utils
+from nova.virt.disk import api as disk
 from nova.virt import driver
 from nova.virt import firewall as base_firewall
 from nova.virt import images
@@ -1803,13 +1804,6 @@ class LibvirtConnTestCase(test.TestCase):
                     "<target dev='vdb' bus='virtio'/></disk>"
                     "</devices></domain>")
 
-        ret = ("image: /test/disk\n"
-               "file format: raw\n"
-               "virtual size: 20G (21474836480 bytes)\n"
-               "disk size: 3.1G\n"
-               "cluster_size: 2097152\n"
-               "backing file: /test/dummy (actual path: /backing/file)\n")
-
         # Preparing mocks
         vdmock = self.mox.CreateMock(libvirt.virDomain)
         self.mox.StubOutWithMock(vdmock, "XMLDesc")
@@ -1829,6 +1823,17 @@ class LibvirtConnTestCase(test.TestCase):
         os.path.getsize('/test/disk').AndReturn((10737418240))
         os.path.getsize('/test/disk.local').AndReturn((21474836480))
 
+        ret = ("image: /test/disk\n"
+               "file format: raw\n"
+               "virtual size: 20G (21474836480 bytes)\n"
+               "disk size: 3.1G\n"
+               "cluster_size: 2097152\n"
+               "backing file: /test/dummy (actual path: /backing/file)\n")
+
+        self.mox.StubOutWithMock(utils, "execute")
+        utils.execute('env', 'LC_ALL=C', 'LANG=C', 'qemu-img', 'info',
+                      '/test/disk.local').AndReturn((ret, ''))
+
         self.mox.ReplayAll()
         conn = libvirt_driver.LibvirtDriver(False)
         info = conn.get_instance_disk_info(instance_ref.name)
@@ -3207,7 +3212,7 @@ disk size: 4.4M''', ''))
 
         # Start test
         self.mox.ReplayAll()
-        self.assertEquals(libvirt_utils.get_disk_size('/some/path'), 4592640)
+        self.assertEquals(disk.get_disk_size('/some/path'), 4592640)
 
     def test_copy_image(self):
         dst_fd, dst_path = tempfile.mkstemp()

nova/virt/disk/api.py

@@ -39,7 +39,7 @@ from nova import utils
 from nova.virt.disk import guestfs
 from nova.virt.disk import loop
 from nova.virt.disk import nbd
-from nova.virt.libvirt import utils as libvirt_utils
+from nova.virt import images
 
 
 LOG = logging.getLogger(__name__)
@@ -103,9 +103,21 @@ def resize2fs(image, check_exit_code=False):
     utils.execute('resize2fs', image, check_exit_code=check_exit_code)
 
 
+def get_disk_size(path):
+    """Get the (virtual) size of a disk image
+
+    :param path: Path to the disk image
+    :returns: Size (in bytes) of the given disk image as it would be seen
+              by a virtual machine.
+    """
+    size = images.qemu_img_info(path)['virtual size']
+    size = size.split('(')[1].split()[0]
+    return int(size)
+
+
 def extend(image, size):
     """Increase image to size"""
-    virt_size = libvirt_utils.get_disk_size(image)
+    virt_size = get_disk_size(image)
     if virt_size >= size:
         return
     utils.execute('qemu-img', 'resize', image, size)
@@ -117,7 +129,7 @@ def can_resize_fs(image, size, use_cow=False):
     """Check whether we can resize contained file system."""
 
     # Check that we're increasing the size
-    virt_size = libvirt_utils.get_disk_size(image)
+    virt_size = get_disk_size(image)
     if virt_size >= size:
         return False
 

nova/virt/libvirt/driver.py

@@ -2667,7 +2667,7 @@ class LibvirtDriver(driver.ComputeDriver):
             disk_type = driver_nodes[cnt].get('type')
             if disk_type == "qcow2":
                 backing_file = libvirt_utils.get_disk_backing_file(path)
-                virt_size = libvirt_utils.get_disk_size(path)
+                virt_size = disk.get_disk_size(path)
             else:
                 backing_file = ""
                 virt_size = 0

nova/virt/libvirt/imagebackend.py

@@ -191,7 +191,7 @@ class Lvm(Image):
     def create_image(self, prepare_template, base, size, *args, **kwargs):
         @utils.synchronized(base)
         def create_lvm_image(base, size):
-            base_size = libvirt_utils.get_disk_size(base)
+            base_size = disk.get_disk_size(base)
             resize = size > base_size
             size = size if resize else base_size
             libvirt_utils.create_lvm_image(self.vg, self.lv,