glusterfs: Implement methods to update share stats

Implement get_share_stats, and _update_share_stats methods.

Change-Id: Id6e9aa130c40561c7fe24e86019751c67580c9e1

manila/share/drivers/glusterfs.py

@@ -90,6 +90,8 @@ class GlusterfsShareDriver(driver.ExecuteMixin, driver.ShareDriver):
         self._helpers = None
         self.gluster_address = None
         self.configuration.append_config_values(GlusterfsManilaShare_opts)
+        self.backend_name = self.configuration.safe_get(
+            'share_backend_name') or 'GlusterFS'
 
     def do_setup(self, context):
         """Native mount the Gluster volume."""
@@ -228,6 +230,45 @@ class GlusterfsShareDriver(driver.ExecuteMixin, driver.ShareDriver):
                                                local_vol_path)
         return os.path.join(local_vol_path, share['name'])
 
+    def get_share_stats(self, refresh=False):
+        """Get share stats.
+
+        If 'refresh' is True, run update the stats first.
+        """
+        if refresh:
+            self._update_share_stats()
+
+        return self._stats
+
+    def _update_share_stats(self):
+        """Retrieve stats info from the GlusterFS volume."""
+
+        # sanity check for gluster ctl mount
+        smpb = os.stat(self.configuration.glusterfs_mount_point_base)
+        smp = os.stat(self._get_mount_point_for_gluster_vol())
+        if smpb.st_dev == smp.st_dev:
+            raise exception.GlusterfsException(
+                     _("GlusterFS control mount is not available")
+                  )
+        smpv = os.statvfs(self._get_mount_point_for_gluster_vol())
+
+        LOG.debug("Updating share stats")
+
+        data = {}
+
+        data["share_backend_name"] = self.backend_name
+        data["vendor_name"] = 'Red Hat'
+        data["driver_version"] = '1.0'
+        data["storage_protocol"] = 'NFS'
+
+        data['reserved_percentage'] = \
+            self.configuration.reserved_share_percentage
+        data['QoS_support'] = False
+
+        data['total_capacity_gb'] = (smpv.f_blocks * smpv.f_frsize) >> 30
+        data['free_capacity_gb'] = (smpv.f_bavail * smpv.f_frsize) >> 30
+        self._stats = data
+
     def create_share(self, ctx, share):
         """Create a directory that'd serve as a share in a Gluster volume."""
         local_share_path = self._get_local_share_path(share)

manila/tests/test_share_glusterfs.py

@@ -117,6 +117,7 @@ class GlusterfsShareDriverTestCase(test.TestCase):
         self._context = context.get_admin_context()
 
         CONF.set_default('glusterfs_mount_point_base', '/mnt/nfs')
+        CONF.set_default('reserved_share_percentage', 50)
 
         self.fake_conf = config.Configuration(None)
         self._db = Mock()
@@ -350,6 +351,49 @@ class GlusterfsShareDriverTestCase(test.TestCase):
                               self._driver._get_local_share_path,
                               self.share)
 
+    def test_get_share_stats_refresh_false(self):
+        self._driver._stats = Mock()
+        ret = self._driver.get_share_stats()
+        self.assertEqual(ret, self._driver._stats)
+
+    def test_get_share_stats_refresh_true(self):
+        def foo():
+            self._driver._stats = {'key': 'value'}
+        self._driver._update_share_stats = Mock(side_effect=foo)
+        ret = self._driver.get_share_stats(refresh=True)
+        self.assertEqual(ret, {'key': 'value'})
+
+    def test_update_share_stats(self):
+        test_data = {
+            'share_backend_name': 'GlusterFS',
+            'vendor_name': 'Red Hat',
+            'driver_version': '1.0',
+            'storage_protocol': 'NFS',
+            'reserved_percentage': 50,
+            'QoS_support': False,
+            'total_capacity_gb': 2,
+            'free_capacity_gb': 2,
+        }
+        test_statvfs = Mock(f_frsize=4096, f_blocks=524288, f_bavail=524288)
+        self._driver._get_mount_point_for_gluster_vol = \
+            Mock(return_value='/mnt/nfs/testvol')
+        some_no = 42
+        not_some_no = some_no + 1
+        os_stat = lambda path: Mock(st_dev=some_no) if path == '/mnt/nfs' \
+                    else Mock(st_dev=not_some_no)
+        with patch.object(os, 'statvfs', return_value=test_statvfs):
+            with patch.object(os, 'stat', os_stat):
+                ret = self._driver._update_share_stats()
+                self.assertEqual(self._driver._stats, test_data)
+
+    def test_update_share_stats_gluster_mnt_unavailable(self):
+        self._driver._get_mount_point_for_gluster_vol = \
+            Mock(return_value='/mnt/nfs/testvol')
+        some_no = 42
+        with patch.object(os, 'stat', return_value=Mock(st_dev=some_no)):
+            self.assertRaises(exception.GlusterfsException,
+                              self._driver._update_share_stats)
+
     def test_create_share(self):
         self._driver._get_local_share_path =\
             Mock(return_value='/mnt/nfs/testvol/fakename')