Move blkid calls to privsep.

The same pattern as before.

Change-Id: If9aaca8dd9c9a82378807bbc5d2c157e719dab4d
blueprint: hurrah-for-privsep

etc/nova/rootwrap.d/compute.filters

@@ -6,9 +6,6 @@
 # nova/virt/xenapi/vm_utils.py: tune2fs, -j, partition_path
 tune2fs: CommandFilter, tune2fs, root
 
-# nova/virt/disk/vfs/localfs.py: 'blkid', '-o', 'value', '-s', 'TYPE', device
-blkid: CommandFilter, blkid, root
-
 # nova/virt/libvirt/utils.py: 'blockdev', '--getsize64', path
 # nova/virt/disk/mount/nbd.py: 'blockdev', '--flushbufs', device
 blockdev: RegExpFilter, blockdev, root, blockdev, (--getsize64|--flushbufs), /dev/.*

nova/privsep/fs.py

@@ -117,3 +117,9 @@ def create_device_maps(device):
 @nova.privsep.sys_admin_pctxt.entrypoint
 def remove_device_maps(device):
     return processutils.execute('kpartx', '-d', device)
+
+
+@nova.privsep.sys_admin_pctxt.entrypoint
+def get_filesystem_type(device):
+    return processutils.execute('blkid', '-o', 'value', '-s', 'TYPE', device,
+                                check_exit_code=[0, 2])

nova/tests/unit/virt/disk/vfs/test_localfs.py

@@ -167,8 +167,9 @@ class VirtDiskVFSLocalFSTest(test.NoDBTestCase):
                                  uid=getpwnam.return_value.pw_uid,
                                  gid=getgrnam.return_value.gr_gid)
 
-    @mock.patch.object(nova.utils, 'execute')
-    def test_get_format_fs(self, execute):
+    @mock.patch('nova.privsep.fs.get_filesystem_type',
+                return_value=('ext3\n', ''))
+    def test_get_format_fs(self, mock_type):
         vfs = vfsimpl.VFSLocalFS(self.rawfile)
         vfs.setup = mock.MagicMock()
         vfs.teardown = mock.MagicMock()
@@ -187,17 +188,12 @@ class VirtDiskVFSLocalFSTest(test.NoDBTestCase):
 
         vfs.setup.side_effect = fake_setup
         vfs.teardown.side_effect = fake_teardown
-        execute.return_value = ('ext3\n', '')
 
         vfs.setup()
         self.assertEqual('ext3', vfs.get_image_fs())
         vfs.teardown()
         vfs.mount.get_dev.assert_called_once_with()
-        execute.assert_called_once_with('blkid', '-o',
-                                        'value', '-s',
-                                        'TYPE', '/dev/xyz',
-                                        run_as_root=True,
-                                        check_exit_code=[0, 2])
+        mock_type.assert_called_once_with('/dev/xyz')
 
     @mock.patch.object(tempfile, 'mkdtemp')
     @mock.patch.object(nbd, 'NbdMount')

nova/virt/disk/vfs/localfs.py

@@ -23,8 +23,8 @@ from oslo_utils import excutils
 
 from nova import exception
 from nova.i18n import _
+import nova.privsep.fs
 import nova.privsep.path
-from nova import utils
 from nova.virt.disk.mount import api as mount_api
 from nova.virt.disk.vfs import api as vfs
 
@@ -142,10 +142,6 @@ class VFSLocalFS(vfs.VFS):
 
     def get_image_fs(self):
         if self.mount.device or self.mount.get_dev():
-            out, err = utils.execute('blkid', '-o',
-                                     'value', '-s',
-                                     'TYPE', self.mount.device,
-                                     run_as_root=True,
-                                     check_exit_code=[0, 2])
+            out, err = nova.privsep.fs.get_filesystem_type(self.mount.device)
             return out.strip()
         return ""

releasenotes/notes/privsep-queens-rootwrap-adds-907aa1bc8e3eb2ca.yaml

@@ -10,6 +10,7 @@ upgrade:
     internal functionality using privsep.
   - |
     The following commands are no longer required to be listed in your rootwrap
-    configuration: cat; chown; cryptsetup; dd; kpartx; losetup; lvcreate;
-    lvremove; lvs; mkdir; mount; nova-idmapshift; ploop; prl_disk_tool;
-    qemu-nbd; readlink; shred; tee; touch; umount; vgs; and xend.
+    configuration: blkid; cat; chown; cryptsetup; dd; kpartx; losetup;
+    lvcreate; lvremove; lvs; mkdir; mount; nova-idmapshift; ploop;
+    prl_disk_tool; qemu-nbd; readlink; shred; tee; touch; umount; vgs;
+    and xend.