Add storage pool support

LXD has grown support for multiple storage pools
defined by name and type (btrfs, zfs, lvm, etc)
and we would like to support this in nova-lxd

Closes-Bug: 1692962

Change-Id: I702d1600fdf70bfd1e2402e3455dd868e25214c0
(cherry picked from commit d883fa99eb)

nova/tests/unit/virt/lxd/test_driver.py

@@ -128,6 +128,7 @@ class LXDDriverTest(test.NoDBTestCase):
         self.patchers.append(CONF2_patcher)
         self.CONF2 = CONF2_patcher.start()
         self.CONF2.lxd.root_dir = '/lxd'
+        self.CONF2.lxd.pool = None
         self.CONF2.instances_path = '/i'
 
         # LXDDriver._after_reboot reads from the database and syncs container

nova/tests/unit/virt/lxd/test_flavor.py

@@ -41,6 +41,11 @@ class ToProfileTest(test.NoDBTestCase):
         self.CONF = CONF_patcher.start()
         self.CONF.instances_path = '/i'
 
+        CONF_patcher = mock.patch('nova.virt.lxd.flavor.CONF')
+        self.patchers.append(CONF_patcher)
+        self.CONF2 = CONF_patcher.start()
+        self.CONF2.lxd.pool = None
+
     def tearDown(self):
         super(ToProfileTest, self).tearDown()
         for patcher in self.patchers:
@@ -104,6 +109,35 @@ class ToProfileTest(test.NoDBTestCase):
         self.client.profiles.create.assert_called_once_with(
             instance.name, expected_config, expected_devices)
 
+    def test_storage_pools(self):
+        self.client.host_info['api_extensions'].append('storage')
+        self.CONF2.lxd.pool = 'test_pool'
+        ctx = context.get_admin_context()
+        instance = fake_instance.fake_instance_obj(
+            ctx, name='test', memory_mb=0)
+        network_info = []
+        block_info = []
+        expected_config = {
+            'environment.product_name': 'OpenStack Nova',
+            'limits.cpu': '1',
+            'limits.memory': '0MB',
+            'raw.lxc': (
+                'lxc.console.logfile=/var/log/lxd/{}/console.log\n'.format(
+                    instance.name))
+        }
+        expected_devices = {
+            'root': {
+                'path': '/',
+                'type': 'disk',
+                'pool': 'test_pool',
+                'size': '0GB'
+            },
+        }
+        flavor.to_profile(self.client, instance, network_info, block_info)
+
+        self.client.profiles.create.assert_called_once_with(
+            instance.name, expected_config, expected_devices)
+
     def test_to_profile_security(self):
         self.client.host_info['api_extensions'].append('id_map')
 

nova/virt/lxd/driver.py

@@ -72,6 +72,9 @@ lxd_opts = [
     cfg.StrOpt('root_dir',
                default='/var/lib/lxd/',
                help='Default LXD directory'),
+    cfg.StrOpt('pool',
+               default=None,
+               help='LXD Storage pool to use with LXD >= 2.9'),
     cfg.IntOpt('timeout',
                default=-1,
                help='Default LXD timeout'),

nova/virt/lxd/flavor.py

@@ -17,12 +17,14 @@ import os
 from nova import exception
 from nova import i18n
 from nova.virt import driver
+from oslo_config import cfg
 from oslo_utils import units
 
 from nova.virt.lxd import common
 from nova.virt.lxd import vif
 
 _ = i18n._
+CONF = cfg.CONF
 
 
 def _base_config(instance, _):
@@ -82,7 +84,7 @@ def _root(instance, client, *_):
     device = {'type': 'disk', 'path': '/'}
 
     environment = client.host_info['environment']
-    if environment['storage'] in ['btrfs', 'zfs']:
+    if environment['storage'] in ['btrfs', 'zfs'] or CONF.lxd.pool:
         device['size'] = '{}GB'.format(instance.root_gb)
 
     specs = instance.flavor.extra_specs
@@ -111,10 +113,17 @@ def _root(instance, client, *_):
     if specs.get('quota:disk_total_bytes_sec') and not minor_quota_defined:
         device['limits.max'] = '{}MB'.format(
             int(specs['quota:disk_total_bytes_sec']) / units.Mi)
+    if CONF.lxd.pool:
+        extensions = client.host_info.get('api_extensions', [])
+        if 'storage' in extensions:
+            device['pool'] = CONF.lxd.pool
+        else:
+            msg = _('Host does not have storage pool support')
+            raise exception.NovaException(msg)
     return {'root': device}
 
 
-def _ephemeral_storage(instance, _, __, block_info):
+def _ephemeral_storage(instance, client, __, block_info):
     instance_attributes = common.InstanceAttributes(instance)
     ephemeral_storage = driver.block_device_info_get_ephemerals(block_info)
     if ephemeral_storage:
@@ -123,11 +132,19 @@ def _ephemeral_storage(instance, _, __, block_info):
             ephemeral_src = os.path.join(
                 instance_attributes.storage_path,
                 ephemeral['virtual_name'])
-            devices[ephemeral['virtual_name']] = {
+            device = {
                 'path': '/mnt',
                 'source': ephemeral_src,
                 'type': 'disk',
             }
+            if CONF.lxd.pool:
+                extensions = client.host_info.get('api_extensions', [])
+                if 'storage' in extensions:
+                    device['pool'] = CONF.lxd.pool
+                else:
+                    msg = _('Host does not have storage pool support')
+                    raise exception.NovaException(msg)
+            devices[ephemeral['virtual_name']] = device
         return devices