lib/ovs/db_client: library for low-level ovsdb manipulation

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>

ryu/lib/ovs/db_client.py

@@ -0,0 +1,132 @@
+# Copyright (C) 2012 Nippon Telegraph and Telephone Corporation.
+# Copyright (C) 2012 Isaku Yamahata <yamahata at private email ne jp>
+#
+# 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 gflags
+import logging
+import os
+
+from ovs import (jsonrpc,
+                 stream)
+from ovs import util as ovs_util
+from ovs.db import schema
+
+FLAGS = gflags.FLAGS
+LOG = logging.getLogger(__name__)
+
+
+class DBClient(object):
+    def __init__(self, remote):
+        super(DBClient, self).__init__()
+        self.remote = remote
+
+    def run_command(self, args):
+        _COMMANDS = {
+            'list-dbs': self._list_dbs,
+            'get-schema': self._get_schema,
+            'get-schema-version': self._get_schema_version,
+            'list-tables': self._list_tables,
+            'list-columns': self._list_columns,
+            'transact': self._transact,
+            'monitor': self._monitor,
+            'dump': self._dump,
+        }
+
+        command = args[0]
+        args = args[1:]
+
+        error, stream_ = stream.Stream.open_block(
+            stream.Stream.open(self.remote))
+        if error:
+            RuntimeError('can not open socket to %s: %s' %
+                         (self.remote, os.strerror(error)))
+            raise
+        rpc = jsonrpc.Connection(stream_)
+
+        ret = _COMMANDS[command](rpc, *args)
+        LOG.info('ret %s', ret)
+        rpc.close()
+
+    def _check_txn(self, error, reply):
+        if error:
+            ovs_util.ovs_fatal(error, os.strerror(error))
+        elif reply.error:
+            ovs_util.ovs_fatal(reply.error, 'error %s' % reply.error)
+
+    def _fetch_dbs(self, rpc):
+        request = jsonrpc.Message.create_request('list_dbs', [])
+        error, reply = rpc.transact_block(request)
+        self._check_txn(error, reply)
+
+        dbs = set()
+        for name in reply.result:
+            dbs.add(name)
+
+        return dbs
+
+    def _fetch_schema_json(self, rpc, database):
+        request = jsonrpc.Message.create_request('get_schema', [database])
+        error, reply = rpc.transact_block(request)
+        self._check_txn(error, reply)
+        return reply.result
+
+    def _fetch_schema(self, rpc, database):
+        return schema.DbSchema.from_json(self._fetch_schema_json(rpc,
+                                                                 database))
+
+    # commands
+    def _list_dbs(self, rpc, *_args):
+        return self._fetch_dbs(rpc)
+
+    def _get_schema(self, rpc, *args):
+        database = args[0]
+        return self._fetch_schema(rpc, database).to_json()
+
+    def _get_schema_version(self, rpc, *_args):
+        database = _args[0]
+        schema_ = self._fetch_schema(rpc, database)
+        return schema_.version
+
+    def _list_tables(self, rpc, *args):
+        database = args[0]
+        schema_ = self._fetch_schema(rpc, database)
+        return [table.to_json() for table in schema_.tables.values()]
+
+    def _list_columns(self, rpc, *args):
+        database = args[0]
+        table_name = None
+        if len(args) > 1:
+            table_name = args[1]
+
+        schema_ = self._fetch_schema(rpc, database)
+        if table_name is None:
+            tables = [table for table in schema_.tables.values()]
+        else:
+            tables = [table for table in schema_.tables.values()
+                      if table.name == table_name]
+
+        columns = []
+        for table in tables:
+            columns.extend(table.columns.values())
+        return [column.to_json() for column in columns]
+
+    def _transact(self, rpc, *args):
+        raise NotImplementedError()
+
+    def _monitor(self, rpc, *args):
+        raise NotImplementedError()
+
+    def _dump(self, rpc, *args):
+        raise NotImplementedError()