Merge "Prevent libvirt driver starting on non Linux platform"

nova/tests/unit/virt/libvirt/test_driver.py

@@ -28,6 +28,7 @@ import random
 import re
 import shutil
 import signal
+import sys
 import testtools
 import threading
 import time
@@ -1053,6 +1054,12 @@ class LibvirtConnTestCase(test.NoDBTestCase,
         drvr = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), False)
         self.assertTrue(drvr.capabilities['supports_image_type_ploop'])
 
+    def test_driver_raises_on_non_linux_platform(self):
+        with utils.temporary_mutation(sys, platform='darwin'):
+            self.assertRaises(
+                exception.InternalError, libvirt_driver.LibvirtDriver,
+                fake.FakeVirtAPI(), False)
+
     def create_fake_libvirt_mock(self, **kwargs):
         """Defining mocks for LibvirtDriver(libvirt is not used)."""
 

nova/virt/libvirt/driver.py

@@ -39,6 +39,7 @@ import os
 import pwd
 import random
 import shutil
+import sys
 import tempfile
 import time
 import typing as ty
@@ -330,6 +331,10 @@ class LibvirtDriver(driver.ComputeDriver):
         }
         super(LibvirtDriver, self).__init__(virtapi)
 
+        if not sys.platform.startswith('linux'):
+            raise exception.InternalError(
+                _('The libvirt driver only works on Linux'))
+
         global libvirt
         if libvirt is None:
             libvirt = importutils.import_module('libvirt')

nova/virt/libvirt/imagecache.py

@@ -359,8 +359,6 @@ class ImageCacheManager(imagecache.ImageCacheManager):
         try:
             # If the cache is on a different device than the instance dir then
             # it does not consume the same disk resource as instances.
-            # NOTE(gibi): this does not work on Windows properly as st_dev is
-            # always 0
             if (os.stat(CONF.instances_path).st_dev !=
                     os.stat(self.cache_dir).st_dev):
                 return 0