ovsdb: Add support for retrieving single record

At present the SimpleOVSDB allows you to find records. The `find` command does however not allow you to match on a records UUID. Add API for retrieval of a specific record by subscripting the SimpleOVSDB Table class.
juju · Sep 12, 2022 · 5195b15 · 5195b15
1 parent 6e302ba
commit 5195b15
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Showing 2 changed files with 92 additions and 41 deletions.
diff --git a/charmhelpers/contrib/network/ovs/ovsdb.py b/charmhelpers/contrib/network/ovs/ovsdb.py
@@ -213,20 +213,14 @@ def _deserialize_ovsdb(self, data):
             f = ovs_type_cb_map.get(data[0], str)
             return f(data[1])
 
-        def _find_tbl(self, condition=None):
-            """Run and parse output of OVSDB `find` command.
+        def _cmd_deserialize_data_generator(self, cmd):
+            """Run command and provide generator with deserialized data.
 
-            :param condition: An optional RFC 7047 5.1 match condition
-            :type condition: Optional[str]
-            :returns: Dictionary with data
-            :rtype: Dict[str, any]
+            :param cmd: Command and arguments to run.
+            :type cmd: Iterable[str]
+            :returns: Deserialzed data.
+            :rtype: Generator[Dict[str,any], None, None]
             """
-            cmd = [self._tool]
-            if self._args:
-                cmd.extend(self._args)
-            cmd.extend(['-f', 'json', 'find', self._table])
-            if condition:
-                cmd.append(condition)
             output = utils._run(*cmd)
             data = json.loads(output)
             for row in data['data']:
@@ -238,9 +232,49 @@ def _find_tbl(self, condition=None):
                         values.append(col)
                 yield dict(zip(data['headings'], values))
 
+        def _get_command(self):
+            """Get base command.
+
+            :rtype: List[str]
+            """
+            cmd = [self._tool]
+            if self._args:
+                cmd.extend(self._args)
+            cmd += ['-f', 'json']
+            return cmd
+
+        def _find_tbl(self, condition=None):
+            """Run and parse output of OVSDB `find` command.
+
+            :param condition: An optional RFC 7047 5.1 match condition
+            :type condition: Optional[str]
+            :returns: Dictionary with data
+            :rtype: Generator[Dict[str, any], None, None]
+            """
+            cmd = self._get_command()
+            cmd.extend(['find', self._table])
+            if condition:
+                cmd.append(condition)
+            return self._cmd_deserialize_data_generator(cmd)
+
+        def _list_tbl_record(self, record):
+            """Run and parse output of OVSDB `list` command for record.
+
+            :param record: The UUID of the record to list data for.
+            :type record: uuid.UUID
+            :returns: Dictionary with data
+            :rtype: Dict[str, any]
+            """
+            cmd = self._get_command()
+            cmd.extend(['list', self._table, str(record)])
+            return next(self._cmd_deserialize_data_generator(cmd))
+
         def __iter__(self):
             return self._find_tbl()
 
+        def __getitem__(self, key):
+            return self._list_tbl_record(key)
+
         def clear(self, rec, col):
             utils._run(self._tool, 'clear', self._table, rec, col)
 

diff --git a/tests/contrib/network/ovs/test_ovsdb.py b/tests/contrib/network/ovs/test_ovsdb.py
@@ -33,6 +33,37 @@
     """)
 
 
+VSCTL_BRIDGE_TBL_DESERIALIZED = {
+    '_uuid': uuid.UUID('1e21ba48-61ff-4b32-b35e-cb80411da351'),
+    'auto_attach': [],
+    'controller': [],
+    'datapath_id': '0000a0369fdd3890',
+    'datapath_type': '',
+    'datapath_version': '<unknown>',
+    'external_ids': {
+        'charm-ovn-chassis': 'managed',
+        'other': 'value',
+    },
+    'fail_mode': [],
+    'flood_vlans': [],
+    'flow_tables': {},
+    'ipfix': [],
+    'mcast_snooping_enable': False,
+    'mirrors': [],
+    'name': 'br-test',
+    'netflow': [],
+    'other_config': {},
+    'ports': [uuid.UUID('617f9359-77e2-41be-8af6-4c44e7a6bcc3'),
+              uuid.UUID('da840476-8809-4107-8733-591f4696f056')],
+    'protocols': ['OpenFlow10', 'OpenFlow13', 'OpenFlow14'],
+    'rstp_enable': False,
+    'rstp_status': {},
+    'sflow': [],
+    'status': {},
+    'stp_enable': False,
+}
+
+
 class TestSimpleOVSDB(test_utils.BaseTestCase):
 
     def patch_target(self, attr, return_value=None):
@@ -55,37 +86,9 @@ def test__find_tbl(self):
         self.patch_object(ovsdb.utils, '_run')
         self._run.return_value = VSCTL_BRIDGE_TBL
         self.maxDiff = None
-        expect = {
-            '_uuid': uuid.UUID('1e21ba48-61ff-4b32-b35e-cb80411da351'),
-            'auto_attach': [],
-            'controller': [],
-            'datapath_id': '0000a0369fdd3890',
-            'datapath_type': '',
-            'datapath_version': '<unknown>',
-            'external_ids': {
-                'charm-ovn-chassis': 'managed',
-                'other': 'value',
-            },
-            'fail_mode': [],
-            'flood_vlans': [],
-            'flow_tables': {},
-            'ipfix': [],
-            'mcast_snooping_enable': False,
-            'mirrors': [],
-            'name': 'br-test',
-            'netflow': [],
-            'other_config': {},
-            'ports': [uuid.UUID('617f9359-77e2-41be-8af6-4c44e7a6bcc3'),
-                      uuid.UUID('da840476-8809-4107-8733-591f4696f056')],
-            'protocols': ['OpenFlow10', 'OpenFlow13', 'OpenFlow14'],
-            'rstp_enable': False,
-            'rstp_status': {},
-            'sflow': [],
-            'status': {},
-            'stp_enable': False}
         # this in effect also tests the __iter__ front end method
         for el in self.target.bridge:
-            self.assertDictEqual(el, expect)
+            self.assertDictEqual(el, VSCTL_BRIDGE_TBL_DESERIALIZED)
             break
         self._run.assert_called_once_with(
             'ovs-vsctl', '-f', 'json', 'find', 'bridge')
@@ -104,6 +107,20 @@ def test__find_tbl(self):
             'ovs-vsctl', 'extra', 'args',
             '-f', 'json', 'find', 'bridge', 'name=br-test')
 
+    def test__list_tbl_record(self):
+        self.target = ovsdb.SimpleOVSDB('ovs-vsctl')
+        self.patch_object(ovsdb.utils, '_run')
+        self._run.return_value = VSCTL_BRIDGE_TBL
+        self.maxDiff = None
+        # this in effect also tests the __getitem__ front end method
+        self.assertEqual(
+            VSCTL_BRIDGE_TBL_DESERIALIZED,
+            self.target.bridge[
+                uuid.UUID('1e21ba48-61ff-4b32-b35e-cb80411da351')])
+        self._run.assert_called_once_with(
+            'ovs-vsctl', '-f', 'json', 'list', 'bridge',
+            '1e21ba48-61ff-4b32-b35e-cb80411da351')
+
     def test_clear(self):
         self.target = ovsdb.SimpleOVSDB('ovs-vsctl')
         self.patch_object(ovsdb.utils, '_run')