Check image exists before calling inject_data

os.stat removal is needed for network-based image backends

Partly revert Change-Id: I264540de736c2bcb92567826fe5ba672e1244ba2
Partly fixes bug #1257674

Change-Id: I83e95fec6f08bc36f0e2b299fb269ceaa3500243

8 files changed, 57 insertions, 34 deletions

diff --git a/nova/tests/fakeguestfs.py b/nova/tests/fakeguestfs.py
index 0d29cb34ca..c8424282d5 100644
--- a/nova/tests/fakeguestfs.py
+++ b/nova/tests/fakeguestfs.py
@@ -40,6 +40,9 @@ class GuestFS(object):
         self.closed = True
 
     def add_drive_opts(self, file, *args, **kwargs):
+        if file == "/some/fail/file":
+            raise RuntimeError("%s: No such file or directory", file)
+
         self.drives.append((file, kwargs['format']))
 
     def inspect_os(self):
diff --git a/nova/tests/virt/baremetal/test_pxe.py b/nova/tests/virt/baremetal/test_pxe.py
index 674a007efd..6787983014 100644
--- a/nova/tests/virt/baremetal/test_pxe.py
+++ b/nova/tests/virt/baremetal/test_pxe.py
@@ -414,6 +414,9 @@ class PXEPrivateMethodsTestCase(BareMetalPXETestCase):
         net = pxe.build_network_config(net_info)
         admin_password = 'fake password'
 
+        self.mox.StubOutWithMock(os.path, 'exists')
+        os.path.exists(mox.IgnoreArg()).AndReturn(True)
+
         self.mox.StubOutWithMock(disk_api, 'inject_data')
         disk_api.inject_data(
                 admin_password=admin_password,
diff --git a/nova/tests/virt/baremetal/test_tilera.py b/nova/tests/virt/baremetal/test_tilera.py
index 0c405452d0..8c1ff40947 100644
--- a/nova/tests/virt/baremetal/test_tilera.py
+++ b/nova/tests/virt/baremetal/test_tilera.py
@@ -19,6 +19,8 @@
 
 import os
 
+import mox
+
 from oslo.config import cfg
 
 from nova import exception
@@ -243,6 +245,9 @@ class TileraPrivateMethodsTestCase(BareMetalTileraTestCase):
         net = tilera.build_network_config(net_info)
         admin_password = 'fake password'
 
+        self.mox.StubOutWithMock(os.path, 'exists')
+        os.path.exists(mox.IgnoreArg()).AndReturn(True)
+
         self.mox.StubOutWithMock(disk_api, 'inject_data')
         disk_api.inject_data(
                 admin_password=admin_password,
diff --git a/nova/tests/virt/libvirt/test_libvirt.py b/nova/tests/virt/libvirt/test_libvirt.py
index 500863c138..faaddc21fe 100644
--- a/nova/tests/virt/libvirt/test_libvirt.py
+++ b/nova/tests/virt/libvirt/test_libvirt.py
@@ -8525,17 +8525,25 @@ class LibvirtDriverTestCase(test.TestCase):
                           called=True):
         conn = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI())
 
-        class i(object):
+        class ImageBackend(object):
             path = '/path'
 
+            def check_image_exists(self):
+                if self.path == '/fail/path':
+                    return False
+                return True
+
         def fake_inj_network(*args, **kwds):
             return args[0] or None
         inj_network.side_effect = fake_inj_network
 
+        image_backend = ImageBackend()
+        image_backend.path = disk_params[0]
+
         with mock.patch.object(
                 conn.image_backend,
                 'image',
-                return_value=i()):
+                return_value=image_backend):
             self.flags(inject_partition=0, group='libvirt')
 
             conn._inject_data(**driver_params)
@@ -8639,6 +8647,18 @@ class LibvirtDriverTestCase(test.TestCase):
         ]
         self._test_inject_data(driver_params, disk_params)
 
+    def test_inject_not_exist_image(self):
+        driver_params = self._test_inject_data_default_driver_params()
+        disk_params = [
+            '/fail/path',  # injection_path
+            'key-content',  # key
+            None,  # net
+            None,  # metadata
+            None,  # admin_pass
+            None,  # files
+        ]
+        self._test_inject_data(driver_params, disk_params, called=False)
+
 
 class LibvirtVolumeUsageTestCase(test.TestCase):
     """Test for LibvirtDriver.get_all_volume_usage."""
diff --git a/nova/tests/virt/test_virt_disk.py b/nova/tests/virt/test_virt_disk.py
index a0f4dcc364..fe886293fb 100644
--- a/nova/tests/virt/test_virt_disk.py
+++ b/nova/tests/virt/test_virt_disk.py
@@ -12,12 +12,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import fixtures
 import os
 import sys
 
-import posix
-
 from nova import exception
 from nova import test
 from nova.tests import fakeguestfs
@@ -34,19 +31,6 @@ class VirtDiskTest(test.NoDBTestCase):
 
     def test_inject_data(self):
 
-        orig_os_stat = os.stat
-
-        def fake_stat(arg):
-            if arg == '/some/file':  # fake success
-                return posix.stat_result((16877, 2, 2049L,
-                                          23, 0, 0,
-                                          4096, 1381787843,
-                                          1381635971, 1381635971))
-            else:
-                return orig_os_stat(arg)
-
-        self.useFixture(fixtures.MonkeyPatch('os.stat', fake_stat))
-
         self.assertTrue(diskapi.inject_data("/some/file", use_cow=True))
 
         self.assertTrue(diskapi.inject_data("/some/file",
@@ -64,7 +48,8 @@ class VirtDiskTest(test.NoDBTestCase):
         self.assertFalse(diskapi.inject_data("/some/file", admin_password="p"))
         os.name = os_name
 
-        self.assertFalse(diskapi.inject_data("/some/fail/file"))
+        self.assertFalse(diskapi.inject_data("/some/fail/file",
+                                             key="mysshkey"))
 
     def test_inject_data_key(self):
 
diff --git a/nova/virt/baremetal/utils.py b/nova/virt/baremetal/utils.py
index 59223a611c..c54d3c14dd 100644
--- a/nova/virt/baremetal/utils.py
+++ b/nova/virt/baremetal/utils.py
@@ -34,11 +34,15 @@ def cache_image(context, target, image_id, user_id, project_id, clean=False):
                                   user_id, project_id)
 
 
-def inject_into_image(image, key, net, metadata, admin_password,
-        files, partition, use_cow=False):
+def inject_into_image(image, key, net, metadata, admin_password, files,
+                      partition, use_cow=False):
     try:
-        disk_api.inject_data(image, key, net, metadata, admin_password,
-                files, partition, use_cow)
+        if os.path.exists(image):
+            disk_api.inject_data(image, key, net, metadata, admin_password,
+                                 files, partition, use_cow)
+        else:
+            LOG.warning(_('Image %s not found on disk storage. '
+                          'Continue without injecting data'), image)
     except Exception as e:
         LOG.warn(_("Failed to inject data into image %(image)s. "
                    "Error: %(e)s"), {'image': image, 'e': e})
diff --git a/nova/virt/disk/api.py b/nova/virt/disk/api.py
index e603ce4843..b78d359caf 100644
--- a/nova/virt/disk/api.py
+++ b/nova/virt/disk/api.py
@@ -347,8 +347,6 @@ def inject_data(image, key=None, net=None, metadata=None, admin_password=None,
     if use_cow:
         fmt = "qcow2"
     try:
-        # Note(mrda): Test if the image exists first to short circuit errors
-        os.stat(image)
         fs = vfs.VFS.instance_for_image(image, fmt, partition)
         fs.setup()
     except Exception as e:
@@ -363,8 +361,8 @@ def inject_data(image, key=None, net=None, metadata=None, admin_password=None,
         return False
 
     try:
-        return inject_data_into_fs(fs, key, net, metadata,
-                                   admin_password, files, mandatory)
+        return inject_data_into_fs(fs, key, net, metadata, admin_password,
+                                   files, mandatory)
     finally:
         fs.teardown()
 
diff --git a/nova/virt/libvirt/driver.py b/nova/virt/libvirt/driver.py
index e6837e2050..940d5da767 100644
--- a/nova/virt/libvirt/driver.py
+++ b/nova/virt/libvirt/driver.py
@@ -2518,18 +2518,23 @@ class LibvirtDriver(driver.ComputeDriver):
 
         image_type = CONF.libvirt.images_type
         if any((key, net, metadata, admin_pass, files)):
-            injection_path = self.image_backend.image(
+            injection_image = self.image_backend.image(
                 instance,
                 'disk' + suffix,
-                image_type).path
+                image_type)
             img_id = instance['image_ref']
 
             try:
-                disk.inject_data(injection_path,
-                                 key, net, metadata, admin_pass, files,
-                                 partition=target_partition,
-                                 use_cow=CONF.use_cow_images,
-                                 mandatory=('files',))
+                if injection_image.check_image_exists():
+                    disk.inject_data(injection_image.path,
+                                     key, net, metadata, admin_pass, files,
+                                     partition=target_partition,
+                                     use_cow=CONF.use_cow_images,
+                                     mandatory=('files',))
+                else:
+                    LOG.warning(_('Image %s not found on disk storage. '
+                                  'Continue without injecting data'),
+                                injection_image.path, instance=instance)
             except Exception as e:
                 with excutils.save_and_reraise_exception():
                     LOG.error(_('Error injecting data into image '