Change force_format strategy to catch mismatches

When we moved the qemu-img command in fetch_to_raw() to force the
format to what we expect, we lost the ability to identify and react
to situations where qemu-img detected a file as a format that is not
supported by us (i.e. identfied and safety-checked by
format_inspector). In the case of some of the other VMDK variants
that we don't support, we need to be sure to catch any case where
qemu-img thinks it's something other than raw when we think it is,
which will be the case for those formats we don't support.

Note this also moves us from explicitly using the format_inspector
that we're told by glance is appropriate, to using our own detection.
We assert that we agree with glance and as above, qemu agrees with
us. This helps us avoid cases where the uploader lies about the
image format, causing us to not run the appropriate safety check.
AMI formats are a liability here since we have a very hard time
asserting what they are and what they will be detected as later in
the pipeline, so there is still special-casing for those.

Closes-Bug: #2071734
Change-Id: I4b792c5bc959a904854c21565682ed3a687baa1a
(cherry picked from commit 8b4c522)
(cherry picked from commit 8ef5ec9)
(cherry picked from commit 45d9489)
(cherry picked from commit fbe4290)

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

@@ -405,12 +405,12 @@ def test_fetch_initrd_image(self, mock_images):
             _context, image_id, target, trusted_certs)
 
     @mock.patch.object(images, 'IMAGE_API')
-    @mock.patch.object(format_inspector, 'get_inspector')
+    @mock.patch.object(format_inspector, 'detect_file_format')
     @mock.patch.object(compute_utils, 'disk_ops_semaphore')
     @mock.patch('nova.privsep.utils.supports_direct_io', return_value=True)
     @mock.patch('nova.privsep.qemu.unprivileged_convert_image')
     def test_fetch_raw_image(self, mock_convert_image, mock_direct_io,
-                             mock_disk_op_sema, mock_gi, mock_glance):
+                             mock_disk_op_sema, mock_detect, mock_glance):
 
         def fake_rename(old, new):
             self.executes.append(('mv', old, new))
@@ -450,7 +450,7 @@ class FakeImgInfo(object):
         self.stub_out('oslo_utils.fileutils.delete_if_exists',
                       fake_rm_on_error)
 
-        mock_inspector = mock_gi.return_value.from_file.return_value
+        mock_inspector = mock_detect.return_value
 
         # Since the remove param of fileutils.remove_path_on_error()
         # is initialized at load time, we must provide a wrapper
@@ -464,6 +464,7 @@ class FakeImgInfo(object):
 
         # Make sure qcow2 gets converted to raw
         mock_inspector.safety_check.return_value = True
+        mock_inspector.__str__.return_value = 'qcow2'
         mock_glance.get.return_value = {'disk_format': 'qcow2'}
         target = 't.qcow2'
         self.executes = []
@@ -477,12 +478,13 @@ class FakeImgInfo(object):
             CONF.instances_path, False)
         mock_convert_image.reset_mock()
         mock_inspector.safety_check.assert_called_once_with()
-        mock_gi.assert_called_once_with('qcow2')
+        mock_detect.assert_called_once_with('t.qcow2.part')
 
         # Make sure raw does not get converted
-        mock_gi.reset_mock()
+        mock_detect.reset_mock()
         mock_inspector.safety_check.reset_mock()
         mock_inspector.safety_check.return_value = True
+        mock_inspector.__str__.return_value = 'raw'
         mock_glance.get.return_value = {'disk_format': 'raw'}
         target = 't.raw'
         self.executes = []
@@ -491,12 +493,13 @@ class FakeImgInfo(object):
         self.assertEqual(self.executes, expected_commands)
         mock_convert_image.assert_not_called()
         mock_inspector.safety_check.assert_called_once_with()
-        mock_gi.assert_called_once_with('raw')
+        mock_detect.assert_called_once_with('t.raw.part')
 
         # Make sure safety check failure prevents us from proceeding
-        mock_gi.reset_mock()
+        mock_detect.reset_mock()
         mock_inspector.safety_check.reset_mock()
         mock_inspector.safety_check.return_value = False
+        mock_inspector.__str__.return_value = 'qcow2'
         mock_glance.get.return_value = {'disk_format': 'qcow2'}
         target = 'backing.qcow2'
         self.executes = []
@@ -506,10 +509,10 @@ class FakeImgInfo(object):
         self.assertEqual(self.executes, expected_commands)
         mock_convert_image.assert_not_called()
         mock_inspector.safety_check.assert_called_once_with()
-        mock_gi.assert_called_once_with('qcow2')
+        mock_detect.assert_called_once_with('backing.qcow2.part')
 
         # Make sure a format mismatch prevents us from proceeding
-        mock_gi.reset_mock()
+        mock_detect.reset_mock()
         mock_inspector.safety_check.reset_mock()
         mock_inspector.safety_check.side_effect = (
             format_inspector.ImageFormatError)
@@ -522,7 +525,7 @@ class FakeImgInfo(object):
         self.assertEqual(self.executes, expected_commands)
         mock_convert_image.assert_not_called()
         mock_inspector.safety_check.assert_called_once_with()
-        mock_gi.assert_called_once_with('qcow2')
+        mock_detect.assert_called_once_with('backing.qcow2.part')
 
         del self.executes
 

nova/tests/unit/virt/test_images.py

@@ -21,7 +21,6 @@
 
 from nova.compute import utils as compute_utils
 from nova import exception
-from nova.image import format_inspector
 from nova import test
 from nova.virt import images
 
@@ -101,15 +100,16 @@ def test_qemu_img_info_with_disk_not_found(self, exists, mocked_execute):
         mocked_execute.assert_called_once()
 
     @mock.patch.object(images, 'IMAGE_API')
-    @mock.patch('nova.image.format_inspector.get_inspector')
+    @mock.patch('nova.image.format_inspector.detect_file_format')
     @mock.patch.object(images, 'convert_image',
                        side_effect=exception.ImageUnacceptable)
     @mock.patch.object(images, 'qemu_img_info')
     @mock.patch.object(images, 'fetch')
     def test_fetch_to_raw_errors(self, convert_image, qemu_img_info, fetch,
-                                 get_inspector, glance):
-        inspector = get_inspector.return_value.from_file.return_value
+                                 mock_detect, glance):
+        inspector = mock_detect.return_value
         inspector.safety_check.return_value = True
+        inspector.__str__.return_value = 'qcow2'
         glance.get.return_value = {'disk_format': 'qcow2'}
         qemu_img_info.backing_file = None
         qemu_img_info.file_format = 'qcow2'
@@ -120,16 +120,17 @@ def test_fetch_to_raw_errors(self, convert_image, qemu_img_info, fetch,
                                None, 'href123', '/no/path')
 
     @mock.patch.object(images, 'IMAGE_API')
-    @mock.patch('nova.image.format_inspector.get_inspector')
+    @mock.patch('nova.image.format_inspector.detect_file_format')
     @mock.patch.object(images, 'convert_image',
                        side_effect=exception.ImageUnacceptable)
     @mock.patch.object(images, 'qemu_img_info')
     @mock.patch.object(images, 'fetch')
     def test_fetch_to_raw_data_file(self, convert_image, qemu_img_info_fn,
-                                    fetch, mock_gi, mock_glance):
+                                    fetch, mock_detect, mock_glance):
         mock_glance.get.return_value = {'disk_format': 'qcow2'}
-        inspector = mock_gi.return_value.from_file.return_value
+        inspector = mock_detect.return_value
         inspector.safety_check.return_value = True
+        inspector.__str__.return_value = 'qcow2'
         # NOTE(danms): the above test needs the following line as well, as it
         # is broken without it.
         qemu_img_info = qemu_img_info_fn.return_value
@@ -142,16 +143,17 @@ def test_fetch_to_raw_data_file(self, convert_image, qemu_img_info_fn,
                                images.fetch_to_raw,
                                None, 'href123', '/no/path')
 
-    @mock.patch('nova.image.format_inspector.get_inspector')
+    @mock.patch('nova.image.format_inspector.detect_file_format')
     @mock.patch.object(images, 'IMAGE_API')
     @mock.patch('os.rename')
     @mock.patch.object(images, 'qemu_img_info')
     @mock.patch.object(images, 'fetch')
     def test_fetch_to_raw_from_raw(self, fetch, qemu_img_info_fn, mock_rename,
-                                   mock_glance, mock_gi):
+                                   mock_glance, mock_detect):
         # Make sure we support a case where we fetch an already-raw image and
         # qemu-img returns None for "format_specific".
         mock_glance.get.return_value = {'disk_format': 'raw'}
+        mock_detect.return_value.__str__.return_value = 'raw'
         qemu_img_info = qemu_img_info_fn.return_value
         qemu_img_info.file_format = 'raw'
         qemu_img_info.backing_file = None
@@ -215,14 +217,15 @@ def test_convert_image_vmdk_allowed_list_checking(self):
                                                  format='json'))
 
     @mock.patch.object(images, 'IMAGE_API')
-    @mock.patch('nova.image.format_inspector.get_inspector')
+    @mock.patch('nova.image.format_inspector.detect_file_format')
     @mock.patch.object(images, 'fetch')
     @mock.patch('nova.privsep.qemu.unprivileged_qemu_img_info')
-    def test_fetch_checks_vmdk_rules(self, mock_info, mock_fetch, mock_gi,
+    def test_fetch_checks_vmdk_rules(self, mock_info, mock_fetch, mock_detect,
                                      mock_glance):
         mock_glance.get.return_value = {'disk_format': 'vmdk'}
-        inspector = mock_gi.return_value.from_file.return_value
+        inspector = mock_detect.return_value
         inspector.safety_check.return_value = True
+        inspector.__str__.return_value = 'vmdk'
         info = {'format': 'vmdk',
                 'format-specific': {
                     'type': 'vmdk',
@@ -238,13 +241,17 @@ def test_fetch_checks_vmdk_rules(self, mock_info, mock_fetch, mock_gi,
     @mock.patch('os.rename')
     @mock.patch.object(images, 'IMAGE_API')
     @mock.patch('nova.image.format_inspector.get_inspector')
+    @mock.patch('nova.image.format_inspector.detect_file_format')
     @mock.patch.object(images, 'fetch')
     @mock.patch('nova.privsep.qemu.unprivileged_qemu_img_info')
-    def test_fetch_iso_is_raw(self, mock_info, mock_fetch, mock_gi,
-                              mock_glance, mock_rename):
+    def test_fetch_iso_is_raw(
+        self, mock_info, mock_fetch, mock_detect_file_format, mock_gi,
+        mock_glance, mock_rename):
         mock_glance.get.return_value = {'disk_format': 'iso'}
         inspector = mock_gi.return_value.from_file.return_value
         inspector.safety_check.return_value = True
+        inspector.__str__.return_value = 'iso'
+        mock_detect_file_format.return_value = inspector
         # qemu-img does not have a parser for iso so it is treated as raw
         info = {
             "virtual-size": 356352,
@@ -258,27 +265,27 @@ def test_fetch_iso_is_raw(self, mock_info, mock_fetch, mock_gi,
             images.fetch_to_raw(None, 'foo', 'anypath')
         # Make sure we called info with -f raw for an iso, since qemu-img does
         # not support iso
-        mock_info.assert_called_once_with('anypath.part', format='raw')
+        mock_info.assert_called_once_with('anypath.part', format=None)
         # Make sure that since we considered this to be a raw file, we did the
         # just-rename-don't-convert path
         mock_rename.assert_called_once_with('anypath.part', 'anypath')
 
     @mock.patch.object(images, 'IMAGE_API')
-    @mock.patch('nova.image.format_inspector.get_inspector')
+    @mock.patch('nova.image.format_inspector.detect_file_format')
     @mock.patch.object(images, 'qemu_img_info')
     @mock.patch.object(images, 'fetch')
-    def test_fetch_to_raw_inspector(self, fetch, qemu_img_info, mock_gi,
+    def test_fetch_to_raw_inspector(self, fetch, qemu_img_info, mock_detect,
                                     mock_glance):
         # Image claims to be qcow2, is qcow2, but fails safety check, so we
         # abort before qemu-img-info
         mock_glance.get.return_value = {'disk_format': 'qcow2'}
-        inspector = mock_gi.return_value.from_file.return_value
+        inspector = mock_detect.return_value
         inspector.safety_check.return_value = False
+        inspector.__str__.return_value = 'qcow2'
         self.assertRaises(exception.ImageUnacceptable,
                           images.fetch_to_raw, None, 'href123', '/no.path')
         qemu_img_info.assert_not_called()
-        mock_gi.assert_called_once_with('qcow2')
-        mock_gi.return_value.from_file.assert_called_once_with('/no.path.part')
+        mock_detect.assert_called_once_with('/no.path.part')
         inspector.safety_check.assert_called_once_with()
         mock_glance.get.assert_called_once_with(None, 'href123')
 
@@ -292,18 +299,17 @@ def test_fetch_to_raw_inspector(self, fetch, qemu_img_info, mock_gi,
         # Image claims to be qcow2 in glance, but the image is something else,
         # so we abort before qemu-img-info
         qemu_img_info.reset_mock()
-        mock_gi.reset_mock()
+        mock_detect.reset_mock()
         inspector.safety_check.reset_mock()
-        mock_gi.return_value.from_file.side_effect = (
-            format_inspector.ImageFormatError)
+        mock_detect.return_value.__str__.return_value = 'vmdk'
         self.assertRaises(exception.ImageUnacceptable,
                           images.fetch_to_raw, None, 'href123', '/no.path')
-        mock_gi.assert_called_once_with('qcow2')
-        inspector.safety_check.assert_not_called()
+        mock_detect.assert_called_once_with('/no.path.part')
+        inspector.safety_check.assert_called_once_with()
         qemu_img_info.assert_not_called()
 
     @mock.patch.object(images, 'IMAGE_API')
-    @mock.patch('nova.image.format_inspector.get_inspector')
+    @mock.patch('nova.image.format_inspector.detect_file_format')
     @mock.patch.object(images, 'qemu_img_info')
     @mock.patch.object(images, 'fetch')
     def test_fetch_to_raw_inspector_disabled(self, fetch, qemu_img_info,
@@ -316,36 +322,41 @@ def test_fetch_to_raw_inspector_disabled(self, fetch, qemu_img_info,
         # If deep inspection is disabled, we should never call the inspector
         mock_gi.assert_not_called()
         # ... and we let qemu-img detect the format itself.
-        qemu_img_info.assert_called_once_with('/no.path.part',
-                                              format=None)
+        qemu_img_info.assert_called_once_with('/no.path.part')
         mock_glance.get.assert_not_called()
 
     @mock.patch.object(images, 'IMAGE_API')
     @mock.patch.object(images, 'qemu_img_info')
-    def test_fetch_inspect_ami(self, imginfo, glance):
+    @mock.patch('nova.image.format_inspector.detect_file_format')
+    def test_fetch_inspect_ami(self, detect, imginfo, glance):
         glance.get.return_value = {'disk_format': 'ami'}
+        detect.return_value.__str__.return_value = 'raw'
         self.assertRaises(exception.ImageUnacceptable,
                           images.fetch_to_raw, None, 'href123', '/no.path')
         # Make sure 'ami was translated into 'raw' before we call qemu-img
-        imginfo.assert_called_once_with('/no.path.part', format='raw')
+        imginfo.assert_called_once_with('/no.path.part')
 
     @mock.patch.object(images, 'IMAGE_API')
     @mock.patch.object(images, 'qemu_img_info')
-    def test_fetch_inspect_aki(self, imginfo, glance):
+    @mock.patch('nova.image.format_inspector.detect_file_format')
+    def test_fetch_inspect_aki(self, detect, imginfo, glance):
         glance.get.return_value = {'disk_format': 'aki'}
+        detect.return_value.__str__.return_value = 'raw'
         self.assertRaises(exception.ImageUnacceptable,
                           images.fetch_to_raw, None, 'href123', '/no.path')
         # Make sure 'aki was translated into 'raw' before we call qemu-img
-        imginfo.assert_called_once_with('/no.path.part', format='raw')
+        imginfo.assert_called_once_with('/no.path.part')
 
     @mock.patch.object(images, 'IMAGE_API')
     @mock.patch.object(images, 'qemu_img_info')
-    def test_fetch_inspect_ari(self, imginfo, glance):
+    @mock.patch('nova.image.format_inspector.detect_file_format')
+    def test_fetch_inspect_ari(self, detect, imginfo, glance):
         glance.get.return_value = {'disk_format': 'ari'}
+        detect.return_value.__str__.return_value = 'raw'
         self.assertRaises(exception.ImageUnacceptable,
                           images.fetch_to_raw, None, 'href123', '/no.path')
         # Make sure 'aki was translated into 'raw' before we call qemu-img
-        imginfo.assert_called_once_with('/no.path.part', format='raw')
+        imginfo.assert_called_once_with('/no.path.part')
 
     @mock.patch.object(images, 'IMAGE_API')
     @mock.patch.object(images, 'qemu_img_info')
@@ -358,13 +369,16 @@ def test_fetch_inspect_unknown_format(self, imginfo, glance):
 
     @mock.patch.object(images, 'IMAGE_API')
     @mock.patch.object(images, 'qemu_img_info')
-    @mock.patch('nova.image.format_inspector.get_inspector')
-    def test_fetch_inspect_disagrees_qemu(self, mock_gi, imginfo, glance):
+    @mock.patch('nova.image.format_inspector.detect_file_format')
+    def test_fetch_inspect_disagrees_qemu(self, mock_detect, imginfo, glance):
         glance.get.return_value = {'disk_format': 'qcow2'}
+        mock_detect.return_value.__str__.return_value = 'qcow2'
         # Glance and inspector think it is a qcow2 file, but qemu-img does not
-        # agree. It was forced to interpret as a qcow2, but returned no
-        # format information as a result.
+        # agree.
         imginfo.return_value.data_file = None
-        self.assertRaises(exception.ImageUnacceptable,
-                          images.fetch_to_raw, None, 'href123', '/no.path')
-        imginfo.assert_called_once_with('/no.path.part', format='qcow2')
+        imginfo.return_value.file_format = 'vmdk'
+        ex = self.assertRaises(exception.ImageUnacceptable,
+                               images.fetch_to_raw,
+                               None, 'href123', '/no.path')
+        self.assertIn('content does not match disk_format', str(ex))
+        imginfo.assert_called_once_with('/no.path.part')