Merge "Adding support for AoE block storage SANs."

4 files changed, 103 insertions, 1 deletions

diff --git a/etc/nova/rootwrap.d/compute.filters b/etc/nova/rootwrap.d/compute.filters
index 9562a23aa..6396315b9 100644
--- a/etc/nova/rootwrap.d/compute.filters
+++ b/etc/nova/rootwrap.d/compute.filters
@@ -88,6 +88,11 @@ dd: CommandFilter, /bin/dd, root
 # nova/virt/xenapi/volume_utils.py: 'iscsiadm', '-m', ...
 iscsiadm: CommandFilter, iscsiadm, root
 
+# nova/virt/libvirt/volume.py: 'aoe-revalidate', aoedev
+# nova/virt/libvirt/volume.py: 'aoe-discover'
+aoe-revalidate: CommandFilter, /usr/sbin/aoe-revalidate, root
+aoe-discover: CommandFilter, /usr/sbin/aoe-discover, root
+
 # nova/virt/xenapi/vm_utils.py: parted, --script, ...
 # nova/virt/xenapi/vm_utils.py: 'parted', '--script', dev_path, ..*.
 parted: CommandFilter, parted, root
diff --git a/nova/tests/test_libvirt_volume.py b/nova/tests/test_libvirt_volume.py
index b9f95735f..c0fa53506 100644
--- a/nova/tests/test_libvirt_volume.py
+++ b/nova/tests/test_libvirt_volume.py
@@ -364,3 +364,31 @@ class LibvirtVolumeTestCase(test.TestCase):
             ('stat', export_mnt_base),
             ('mount', '-t', 'nfs', export_string, export_mnt_base)]
         self.assertEqual(self.executes, expected_commands)
+
+    def aoe_connection(self, shelf, lun):
+        return {
+                'driver_volume_type': 'aoe',
+                'data': {
+                    'target_shelf': shelf,
+                    'target_lun': lun,
+                }
+        }
+
+    def test_libvirt_aoe_driver(self):
+        # NOTE(jbr_) exists is to make driver assume connecting worked
+        self.stubs.Set(os.path, 'exists', lambda x: True)
+        libvirt_driver = volume.LibvirtAOEVolumeDriver(self.fake_conn)
+        shelf = '100'
+        lun = '1'
+        connection_info = self.aoe_connection(shelf, lun)
+        disk_info = {
+            "bus": "virtio",
+            "dev": "vde",
+            "type": "disk",
+            }
+        conf = libvirt_driver.connect_volume(connection_info, disk_info)
+        tree = conf.format_dom()
+        aoedevpath = '/dev/etherd/e%s.%s' % (shelf, lun)
+        self.assertEqual(tree.get('type'), 'block')
+        self.assertEqual(tree.find('./source').get('dev'), aoedevpath)
+        libvirt_driver.disconnect_volume(connection_info, "vde")
diff --git a/nova/virt/libvirt/driver.py b/nova/virt/libvirt/driver.py
index 7e34aef3d..b65789b10 100755
--- a/nova/virt/libvirt/driver.py
+++ b/nova/virt/libvirt/driver.py
@@ -151,7 +151,8 @@ libvirt_opts = [
                   'fake=nova.virt.libvirt.volume.LibvirtFakeVolumeDriver',
                   'rbd=nova.virt.libvirt.volume.LibvirtNetVolumeDriver',
                   'sheepdog=nova.virt.libvirt.volume.LibvirtNetVolumeDriver',
-                  'nfs=nova.virt.libvirt.volume.LibvirtNFSVolumeDriver'
+                  'nfs=nova.virt.libvirt.volume.LibvirtNFSVolumeDriver',
+                  'aoe=nova.virt.libvirt.volume.LibvirtAOEVolumeDriver'
                   ],
                 help='Libvirt handlers for remote volumes.'),
     cfg.StrOpt('libvirt_disk_prefix',
diff --git a/nova/virt/libvirt/volume.py b/nova/virt/libvirt/volume.py
index 724a859b8..9ec8f6bcb 100644
--- a/nova/virt/libvirt/volume.py
+++ b/nova/virt/libvirt/volume.py
@@ -50,6 +50,9 @@ volume_opts = [
                default=None,
                help='Mount options passed to the nfs client. See section '
                     'of the nfs man page for details'),
+    cfg.StrOpt('num_aoe_discover_tries',
+               default=3,
+               help='number of times to rediscover AoE target to find volume')
     ]
 
 CONF = cfg.CONF
@@ -322,3 +325,68 @@ class LibvirtNFSVolumeDriver(LibvirtBaseVolumeDriver):
             return utils.execute('stat', path, run_as_root=True)
         except exception.ProcessExecutionError:
             return False
+
+
+class LibvirtAOEVolumeDriver(LibvirtBaseVolumeDriver):
+    """Driver to attach AoE volumes to libvirt."""
+    def __init__(self, connection):
+        super(LibvirtAOEVolumeDriver,
+              self).__init__(connection, is_block_dev=True)
+
+    def _aoe_discover(self):
+        """Call aoe-discover (aoe-tools) AoE Discover."""
+        (out, err) = utils.execute('aoe-discover',
+                                   run_as_root=True, check_exit_code=0)
+        return (out, err)
+
+    def _aoe_revalidate(self, aoedev):
+        """Revalidate the LUN Geometry (When an AoE ID is reused)."""
+        (out, err) = utils.execute('aoe-revalidate', aoedev,
+                                   run_as_root=True, check_exit_code=0)
+        return (out, err)
+
+    def connect_volume(self, connection_info, mount_device):
+        shelf = connection_info['data']['target_shelf']
+        lun = connection_info['data']['target_lun']
+        aoedev = 'e%s.%s' % (shelf, lun)
+        aoedevpath = '/dev/etherd/%s' % (aoedev)
+
+        if os.path.exists(aoedevpath):
+            # NOTE(jbr_): If aoedevpath already exists, revalidate the LUN.
+            self._aoe_revalidate(aoedev)
+        else:
+            # NOTE(jbr_): If aoedevpath does not exist, do a discover.
+            self._aoe_discover()
+
+        #NOTE(jbr_): Device path is not always present immediately
+        def _wait_for_device_discovery(aoedevpath, mount_device):
+            tries = self.tries
+            if os.path.exists(aoedevpath):
+                raise utils.LoopingCallDone()
+
+            if self.tries >= CONF.num_aoe_discover_tries:
+                raise exception.NovaException(_("AoE device not found at %s") %
+                                                (aoedevpath))
+            LOG.warn(_("AoE volume not yet found at: %(aoedevpath)s. "
+                       "Try number: %(tries)s") %
+                     locals())
+
+            self._aoe_discover()
+            self.tries = self.tries + 1
+
+        self.tries = 0
+        timer = utils.FixedIntervalLoopingCall(_wait_for_device_discovery,
+                                               aoedevpath, mount_device)
+        timer.start(interval=2).wait()
+
+        tries = self.tries
+        if tries != 0:
+            LOG.debug(_("Found AoE device %(aoedevpath)s "
+                        "(after %(tries)s rediscover)") %
+                      locals())
+
+        conf = super(LibvirtAOEVolumeDriver,
+                     self).connect_volume(connection_info, mount_device)
+        conf.source_type = "block"
+        conf.source_path = aoedevpath
+        return conf