Merge "Add support for LXC volumes."

nova/tests/test_libvirt.py

@@ -195,6 +195,27 @@ class LibvirtVolumeTestCase(test.TestCase):
         libvirt_driver.disconnect_volume(connection_info, mount_device)
         connection_info = vol_driver.terminate_connection(vol, self.connr)
 
+    def test_libvirt_lxc_volume(self):
+        self.stubs.Set(os.path, 'exists', lambda x: True)
+        vol_driver = volume_driver.ISCSIDriver()
+        libvirt_driver = volume.LibvirtISCSIVolumeDriver(self.fake_conn)
+        location = '10.0.2.15:3260'
+        name = 'volume-00000001'
+        iqn = 'iqn.2010-10.org.openstack:%s' % name
+        vol = {'id': 1,
+               'name': name,
+               'provider_auth': None,
+               'provider_location': '%s,fake %s' % (location, iqn)}
+        connection_info = vol_driver.initialize_connection(vol, self.connr)
+        mount_device = "vde"
+        xml = libvirt_driver.connect_volume(connection_info, mount_device)
+        tree = xml_to_tree(xml)
+        dev_str = '/dev/disk/by-path/ip-%s-iscsi-%s-lun-0' % (location, iqn)
+        self.assertEqual(tree.get('type'), 'block')
+        self.assertEqual(tree.find('./source').get('dev'), dev_str)
+        libvirt_driver.disconnect_volume(connection_info, mount_device)
+        connection_info = vol_driver.terminate_connection(vol, self.connr)
+
 
 class CacheConcurrencyTestCase(test.TestCase):
     def setUp(self):

nova/virt/disk/api.py

@@ -106,6 +106,26 @@ def extend(image, size):
     utils.execute('resize2fs', image, check_exit_code=False)
 
 
+def bind(src, target, instance_name):
+    """Bind device to a filesytem"""
+    if src:
+        utils.execute('touch', target, run_as_root=True)
+        utils.execute('mount', '-o', 'bind', src, target,
+                run_as_root=True)
+        s = os.stat(src)
+        cgroup_info = "c %s:%s rwm" % (os.major(s.st_rdev),
+                                       os.minor(s.st_rdev))
+        cgroups_path = \
+            "/sys/fs/cgroup/devices/sysdefault/libvirt/lxc/%s/devices.allow" \
+            % instance_name
+        utils.execute('echo', '>', cgroup_info, cgroups_path, run_as_root=True)
+
+
+def unbind(target):
+    if target:
+        utils.execute('umount', target, run_as_root=True)
+
+
 class _DiskImage(object):
     """Provide operations on a disk image file."""
 

nova/virt/libvirt/connection.py

@@ -453,7 +453,11 @@ class LibvirtConnection(driver.ComputeDriver):
         xml = self.volume_driver_method('connect_volume',
                                         connection_info,
                                         mount_device)
-        virt_dom.attachDevice(xml)
+
+        if FLAGS.libvirt_type == 'lxc':
+            self._attach_lxc_volume(xml, virt_dom, instance_name)
+        else:
+            virt_dom.attachDevice(xml)
 
     @staticmethod
     def _get_disk_xml(xml, device):
@@ -480,12 +484,64 @@ class LibvirtConnection(driver.ComputeDriver):
             xml = self._get_disk_xml(virt_dom.XMLDesc(0), mount_device)
             if not xml:
                 raise exception.DiskNotFound(location=mount_device)
-            virt_dom.detachDevice(xml)
+            if FLAGS.libvirt_type == 'lxc':
+                self._detach_lxc_volume(xml, vort_dom, instance_name)
+            else:
+                virt_dom.detachDevice(xml)
         finally:
             self.volume_driver_method('disconnect_volume',
                                       connection_info,
                                       mount_device)
 
+    @exception.wrap_exception()
+    def _attach_lxc_volume(self, xml, virt_dom, instance_name):
+        LOG.info(_('attaching LXC block device'))
+
+        lxc_container_root = self.get_lxc_container_root(virt_dom)
+        lxc_host_volume = self.get_lxc_host_device(xml)
+        lxc_container_device = self.get_lxc_container_target(xml)
+        lxc_container_target = "%s/%s" % (lxc_container_root,
+                                          lxc_container_device)
+
+        if lxc_container_target:
+            disk.bind(lxc_host_volume, lxc_container_target, instance_name)
+
+    @exception.wrap_exception()
+    def _detach_lxc_volume(self, xml, virt_dom, instance_name):
+        LOG.info(_('detaching LXC block device'))
+
+        lxc_container_root = self.get_lxc_container_root(virt_dom)
+        lxc_host_volume = self.get_lxc_host_device(xml)
+        lxc_container_device = self.get_lxc_container_target(xml)
+        lxc_container_target = "%s/%s" % (lxc_container_root,
+                                          lxc_container_device)
+
+        if lxc_container_target:
+            disk.unbind(lxc_container_target)
+
+    @staticmethod
+    def get_lxc_container_root(virt_dom):
+        xml = virt_dom.XMLDesc(0)
+        doc = ElementTree.fromstring(xml)
+        filesystem_block = doc.findall('./devices/filesystem')
+        for cnt, filesystem_nodes in enumerate(filesystem_block):
+            return filesystem_nodes[cnt].get('dir')
+
+    @staticmethod
+    def get_lxc_host_device(xml):
+        dom = minidom.parseString(xml)
+
+        for device in dom.getElementsByTagName('source'):
+            return device.getAttribute('dev')
+
+    @staticmethod
+    def get_lxc_container_target(xml):
+        dom = minidom.parseString(xml)
+
+        for device in dom.getElementsByTagName('target'):
+            filesystem = device.getAttribute('dev')
+            return 'dev/%s' % filesystem
+
     @exception.wrap_exception()
     def snapshot(self, context, instance, image_href):
         """Create snapshot from a running VM instance.