Lightbits LightOS driver

This commit introduces the LightOS driver for nova. LightOS is a
software-defined disaggregated clustered storage solution running on
commodity servers with commodity SSDs. It it developed by Lightbits
Labs (https://www.lightbitslabs.com) and is actively developed and
maintained. LightOS is proprietary but the openstack drivers are
licensed under Apache v2.0.

The Cinder driver for LightOS currently supports the following
functionality:

Create volume
Delete volume
Attach volume
Detach volume
Create image from volume
create volume from image
Live migration
Volume replication
Thin provisioning
Multi-attach
Extend volume
Create snapshot
Delete snapshot
Create volume from snapshot
Create volume from volume (clone)

This driver has been developed and has been in use for a couple of
years by Lightbits and our clients. We have tested it extensively
internally with multiple openstack versions, including Queens, Rocky,
Stein, and Train. We have also tested it with master (19.1 xena) and we
are working to extend testing to cover additional openstack releases.

We are glad to join the openstack community and hope to get your
feedback and comments on this driver, and if it is acceptable, to see
it merged into the tree.

Note: the patch depends on os-brick 5.2.0. That version also increased
the lower constraints of several dependencies, thus needs nova to
increase those as well in requirements.txt, lower-constraints.txt and
setup.cfg.

Depends-On: I2e86fa84049053b7c75421d33ad1a1af459ef4e0
Signed-off-by: Yuval Brave  yuval@lightbitslabs.com
Change-Id: Ic314b26695d9681d31a18adcec0794c2ff41fe71

1 files changed, 63 insertions, 0 deletions

diff --git a/nova/virt/libvirt/volume/lightos.py b/nova/virt/libvirt/volume/lightos.py
new file mode 100644
index 0000000000..d6d393994e
--- /dev/null
+++ b/nova/virt/libvirt/volume/lightos.py
@@ -0,0 +1,63 @@
+# Copyright (C) 2016-2020 Lightbits Labs Ltd.
+# Copyright (C) 2020 Intel Corporation
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import nova.conf
+from nova import utils
+from nova.virt.libvirt.volume import volume as libvirt_volume
+from os_brick import initiator
+from os_brick.initiator import connector
+from oslo_log import log as logging
+
+
+LOG = logging.getLogger(__name__)
+CONF = nova.conf.CONF
+
+
+class LibvirtLightOSVolumeDriver(libvirt_volume.LibvirtVolumeDriver):
+    """Driver to attach NVMe volumes to libvirt."""
+    VERSION = '2.3.12'
+
+    def __init__(self, connection):
+        super(LibvirtLightOSVolumeDriver, self).__init__(connection)
+        self.connector = connector.InitiatorConnector.factory(
+            initiator.LIGHTOS,
+            root_helper=utils.get_root_helper(),
+            device_scan_attempts=CONF.libvirt.num_nvme_discover_tries)
+
+    def connect_volume(self, connection_info, instance):
+        device_info = self.connector.connect_volume(connection_info['data'])
+        LOG.debug("Connecting NVMe volume with device_info %s", device_info)
+        connection_info['data']['device_path'] = device_info['path']
+
+    def disconnect_volume(self, connection_info, instance):
+        """Detach the volume from the instance."""
+        LOG.debug("Disconnecting NVMe disk. instance:%s, volume_id:%s",
+                  connection_info.get("instance", ""),
+                  connection_info.get("volume_id", ""))
+        self.connector.disconnect_volume(connection_info['data'], None)
+        super(LibvirtLightOSVolumeDriver, self).disconnect_volume(
+            connection_info, instance)
+
+    def extend_volume(self, connection_info, instance, requested_size=None):
+        """Extend the volume."""
+        LOG.debug("calling os-brick to extend LightOS Volume."
+                  "instance:%s, volume_id:%s",
+                  connection_info.get("instance", ""),
+                  connection_info.get("volume_id", ""))
+        new_size = self.connector.extend_volume(connection_info['data'])
+        LOG.debug("Extend LightOS Volume %s; new_size=%s",
+                  connection_info['data']['device_path'], new_size)
+        return new_size