Merge "Adding Read-Only volume attaching support to Nova"

nova/exception.py

@@ -277,6 +277,10 @@ class InvalidVolume(Invalid):
     msg_fmt = _("Invalid volume") + ": %(reason)s"
 
 
+class InvalidVolumeAccessMode(Invalid):
+    msg_fmt = _("Invalid volume access mode") + ": %(access_mode)s"
+
+
 class InvalidMetadata(Invalid):
     msg_fmt = _("Invalid metadata") + ": %(reason)s"
 

nova/tests/virt/libvirt/test_libvirt_config.py

@@ -1487,6 +1487,31 @@ class LibvirtConfigNodeDevicePciCapTest(LibvirtConfigBaseTest):
         self.assertEqual(obj.fun_capability[1].device_addrs,
                          [("0000", '0x0a', '0x1', "0x1"), ])
 
+        def test_config_read_only_disk(self):
+            obj = config.LibvirtConfigGuestDisk()
+            obj.source_type = "disk"
+            obj.source_device = "disk"
+            obj.driver_name = "kvm"
+            obj.target_dev = "/dev/hdc"
+            obj.target_bus = "virtio"
+            obj.readonly = True
+
+            xml = obj.to_xml()
+            self.assertXmlEqual(xml, """
+                <disk type="disk" device="disk">
+                    <driver name="kvm"/>
+                    <target bus="virtio" dev="/dev/hdc"/>
+                    <readonly/>
+                </disk>""")
+
+            obj.readonly = False
+            xml = obj.to_xml()
+            self.assertXmlEqual(xml, """
+                <disk type="disk" device="disk">
+                    <driver name="kvm"/>
+                    <target bus="virtio" dev="/dev/hdc"/>
+                </disk>""")
+
 
 class LibvirtConfigNodeDevicePciSubFunctionCap(LibvirtConfigBaseTest):
 

nova/tests/virt/libvirt/test_libvirt_volume.py

@@ -194,6 +194,36 @@ class LibvirtVolumeTestCase(test.NoDBTestCase):
         self.assertEqual('200', tree.find('./iotune/read_iops_sec').text)
         self.assertEqual('200', tree.find('./iotune/write_iops_sec').text)
 
+    def test_libvirt_volume_driver_readonly(self):
+        libvirt_driver = volume.LibvirtVolumeDriver(self.fake_conn)
+        connection_info = {
+            'driver_volume_type': 'fake',
+            'data': {
+                "device_path": "/foo",
+                'access_mode': 'bar',
+                },
+            }
+        disk_info = {
+            "bus": "virtio",
+            "dev": "vde",
+            "type": "disk",
+            }
+        self.assertRaises(exception.InvalidVolumeAccessMode,
+                          libvirt_driver.connect_volume,
+                          connection_info, self.disk_info)
+
+        connection_info['data']['access_mode'] = 'rw'
+        conf = libvirt_driver.connect_volume(connection_info, disk_info)
+        tree = conf.format_dom()
+        readonly = tree.find('./readonly')
+        self.assertEqual(readonly, None)
+
+        connection_info['data']['access_mode'] = 'ro'
+        conf = libvirt_driver.connect_volume(connection_info, disk_info)
+        tree = conf.format_dom()
+        readonly = tree.find('./readonly')
+        self.assertNotEqual(readonly, None)
+
     def iscsi_connection(self, volume, location, iqn):
         return {
                 'driver_volume_type': 'iscsi',

nova/virt/libvirt/config.py

@@ -479,6 +479,7 @@ class LibvirtConfigGuestDisk(LibvirtConfigGuestDevice):
         self.disk_total_iops_sec = None
         self.logical_block_size = None
         self.physical_block_size = None
+        self.readonly = False
 
     def format_dom(self):
         dev = super(LibvirtConfigGuestDisk, self).format_dom()
@@ -573,6 +574,9 @@ class LibvirtConfigGuestDisk(LibvirtConfigGuestDevice):
 
             dev.append(blockio)
 
+        if self.readonly:
+            dev.append(etree.Element("readonly"))
+
         return dev
 
     def parse_dom(self, xmldoc):

nova/virt/libvirt/volume.py

@@ -131,6 +131,18 @@ class LibvirtBaseVolumeDriver(object):
                 LOG.warn(_('Unknown content in connection_info/'
                            'qos_specs: %s') % specs)
 
+        # Extract access_mode control parameters
+        if 'access_mode' in data and data['access_mode']:
+            access_mode = data['access_mode']
+            if access_mode in ('ro', 'rw'):
+                conf.readonly = access_mode == 'ro'
+            else:
+                msg = (_('Unknown content in connection_info/access_mode: %s')
+                       % access_mode)
+                LOG.error(msg)
+                raise exception.InvalidVolumeAccessMode(
+                                                    access_mode=access_mode)
+
         return conf
 
     def disconnect_volume(self, connection_info, disk_dev):