Adding OsloRPC server and client

* Using new RPC interface OsloRPCServer and
   OsloRPCClient are created.

TODO (next commits):
 - integrate new RPC interface in Mistral
 - make RPC implementation configurable
 - unit tests

Partially implements blueprint mistral-alternative-rpc

Co-Authored-By: Dawid Deja <dawid.deja@intel.com>
Change-Id: I6c9770a5b84509529abc14dff2b4a9f6e3411951

mistral/api/controllers/v2/action_execution.py

@@ -25,7 +25,7 @@ from mistral.api.controllers import resource
 from mistral.api.controllers.v2 import types
 from mistral import context
 from mistral.db.v2 import api as db_api
-from mistral.engine import rpc
+from mistral.engine.rpc import rpc
 from mistral import exceptions as exc
 from mistral.utils import rest_utils
 from mistral.workflow import states

mistral/api/controllers/v2/execution.py

@@ -25,7 +25,7 @@ from mistral.api.controllers.v2 import task
 from mistral.api.controllers.v2 import types
 from mistral import context
 from mistral.db.v2 import api as db_api
-from mistral.engine import rpc
+from mistral.engine.rpc import rpc
 from mistral import exceptions as exc
 from mistral.services import workflows as wf_service
 from mistral.utils import rest_utils

mistral/api/controllers/v2/task.py

@@ -27,7 +27,7 @@ from mistral.api.controllers.v2 import action_execution
 from mistral.api.controllers.v2 import types
 from mistral import context
 from mistral.db.v2 import api as db_api
-from mistral.engine import rpc
+from mistral.engine.rpc import rpc
 from mistral import exceptions as exc
 from mistral.utils import rest_utils
 from mistral.workbook import parser as spec_parser

mistral/cmd/launch.py

@@ -17,6 +17,7 @@ import sys
 
 import eventlet
 
+
 eventlet.monkey_patch(
     os=True,
     select=True,
@@ -54,7 +55,7 @@ from mistral import context as ctx
 from mistral.db.v2 import api as db_api
 from mistral.engine import default_engine as def_eng
 from mistral.engine import default_executor as def_executor
-from mistral.engine import rpc
+from mistral.engine.rpc import rpc
 from mistral.services import expiration_policy
 from mistral.services import scheduler
 from mistral.utils import profiler

mistral/engine/actions.py

@@ -20,7 +20,7 @@ from osprofiler import profiler
 import six
 
 from mistral.db.v2 import api as db_api
-from mistral.engine import rpc
+from mistral.engine.rpc import rpc
 from mistral.engine import utils as e_utils
 from mistral.engine import workflow_handler as wf_handler
 from mistral import exceptions as exc

mistral/engine/rpc/kombu/examples/client.py

@@ -12,7 +12,7 @@
 #    See the License for the specific language governing permissions and
 #    limitations under the License.
 
-from mistral.engine.rpc_direct.kombu import kombu_client
+from mistral.engine.rpc.kombu import kombu_client
 
 
 # Example of using Kombu based RPC client.

mistral/engine/rpc/kombu/examples/server.py

@@ -12,7 +12,7 @@
 #    See the License for the specific language governing permissions and
 #    limitations under the License.
 
-from mistral.engine.rpc_direct.kombu import kombu_server
+from mistral.engine.rpc.kombu import kombu_server
 
 
 # Simple example of endpoint of RPC server, which just

mistral/engine/rpc/kombu/kombu_client.py

@@ -18,8 +18,8 @@ import time
 import kombu
 from oslo_log import log as logging
 
-from mistral.engine.rpc_direct import base as rpc_base
-from mistral.engine.rpc_direct.kombu import base as kombu_base
+from mistral.engine.rpc import base as rpc_base
+from mistral.engine.rpc.kombu import base as kombu_base
 from mistral import exceptions as exc
 from mistral import utils
 

mistral/engine/rpc/kombu/kombu_server.py

@@ -19,8 +19,8 @@ import kombu
 from oslo_log import log as logging
 
 from mistral import context as auth_context
-from mistral.engine.rpc_direct import base as rpc_base
-from mistral.engine.rpc_direct.kombu import base as kombu_base
+from mistral.engine.rpc import base as rpc_base
+from mistral.engine.rpc.kombu import base as kombu_base
 from mistral import exceptions as exc
 
 

mistral/engine/rpc/oslo/oslo_client.py

@@ -0,0 +1,48 @@
+# Copyright 2015 - Mirantis, Inc.
+#
+# 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 oslo_messaging as messaging
+
+from mistral import context as auth_ctx
+from mistral.engine.rpc import base as rpc_base
+from mistral.engine.rpc import rpc
+
+
+class OsloRPCClient(rpc_base.RPCClient):
+    def __init__(self, conf):
+        super(OsloRPCClient, self).__init__(conf)
+        self.topic = conf.get('topic', '')
+
+        serializer = auth_ctx.RpcContextSerializer(
+            auth_ctx.JsonPayloadSerializer())
+
+        self._client = messaging.RPCClient(
+            rpc.get_transport(),
+            messaging.Target(topic=self.topic),
+            serializer=serializer
+        )
+
+    def sync_call(self, ctx, method, target=None, **kwargs):
+        return self._client.prepare(topic=self.topic, server=target).call(
+            ctx,
+            method,
+            **kwargs
+        )
+
+    def async_call(self, ctx, method, target=None, **kwargs):
+        return self._client.prepare(topic=self.topic, server=target).cast(
+            ctx,
+            method,
+            **kwargs
+        )

mistral/engine/rpc/oslo/oslo_server.py

@@ -0,0 +1,56 @@
+# Copyright 2015 - Mirantis, Inc.
+#
+# 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.
+
+from oslo_log import log as logging
+import oslo_messaging as messaging
+
+from mistral import context as ctx
+from mistral.engine.rpc import base as rpc_base
+from mistral.engine.rpc import rpc
+
+
+LOG = logging.getLogger(__name__)
+
+
+class OsloRPCServer(rpc_base.RPCServer):
+    def __init__(self, conf):
+        super(OsloRPCServer, self).__init__(conf)
+
+        self.topic = conf.get('topic', '')
+        self.server_id = conf.get('server_id', '')
+        self.queue = self.topic
+        self.routing_key = self.topic
+        self.channel = None
+        self.connection = None
+        self.endpoints = []
+
+    def register_endpoint(self, endpoint):
+        self.endpoints.append(endpoint)
+
+    def run(self):
+        target = messaging.Target(
+            topic=self.topic,
+            server=self.server_id
+        )
+
+        server = messaging.get_rpc_server(
+            rpc.get_transport(),
+            target,
+            self.endpoints,
+            executor='eventlet',
+            serializer=ctx.RpcContextSerializer(ctx.JsonPayloadSerializer())
+        )
+
+        server.start()
+        server.wait()

mistral/engine/workflows.py

@@ -23,7 +23,7 @@ import six
 from mistral.db.v2 import api as db_api
 from mistral.db.v2.sqlalchemy import models as db_models
 from mistral.engine import dispatcher
-from mistral.engine import rpc
+from mistral.engine.rpc import rpc
 from mistral.engine import utils as eng_utils
 from mistral import exceptions as exc
 from mistral.services import scheduler

mistral/services/periodic.py

@@ -21,7 +21,7 @@ from oslo_service import threadgroup
 
 from mistral import context as auth_ctx
 from mistral.db.v2 import api as db_api_v2
-from mistral.engine import rpc
+from mistral.engine.rpc import rpc
 from mistral import exceptions as exc
 from mistral.services import security
 from mistral.services import triggers

mistral/tests/unit/api/v2/test_action_executions.py

@@ -23,7 +23,7 @@ from oslo_config import cfg
 
 from mistral.db.v2 import api as db_api
 from mistral.db.v2.sqlalchemy import models
-from mistral.engine import rpc
+from mistral.engine.rpc import rpc
 from mistral import exceptions as exc
 from mistral.tests.unit.api import base
 from mistral.workflow import states

mistral/tests/unit/api/v2/test_executions.py

@@ -17,6 +17,7 @@
 import copy
 import datetime
 import json
+
 import mock
 import uuid
 from webtest import app as webtest_app
@@ -24,12 +25,13 @@ from webtest import app as webtest_app
 from mistral.db.v2 import api as db_api
 from mistral.db.v2.sqlalchemy import api as sql_db_api
 from mistral.db.v2.sqlalchemy import models
-from mistral.engine import rpc
+from mistral.engine.rpc import rpc
 from mistral import exceptions as exc
 from mistral.tests.unit.api import base
 from mistral import utils
 from mistral.workflow import states
 
+
 WF_EX = models.WorkflowExecution(
     id='123e4567-e89b-12d3-a456-426655440000',
     workflow_name='some',

mistral/tests/unit/api/v2/test_tasks.py

@@ -20,7 +20,7 @@ import mock
 
 from mistral.db.v2 import api as db_api
 from mistral.db.v2.sqlalchemy import models
-from mistral.engine import rpc
+from mistral.engine.rpc import rpc
 from mistral import exceptions as exc
 from mistral.tests.unit.api import base
 from mistral.workflow import data_flow

mistral/tests/unit/engine/base.py

@@ -22,11 +22,12 @@ from mistral import context as ctx
 from mistral.db.v2 import api as db_api
 from mistral.engine import default_engine as def_eng
 from mistral.engine import default_executor as def_exec
-from mistral.engine import rpc
+from mistral.engine.rpc import rpc
 from mistral.services import scheduler
 from mistral.tests.unit import base
 from mistral.workflow import states
 
+
 LOG = logging.getLogger(__name__)
 
 # Default delay and timeout in seconds for await_xxx() functions.

mistral/tests/unit/engine/test_environment.py

@@ -17,7 +17,7 @@ from oslo_config import cfg
 
 from mistral.db.v2 import api as db_api
 from mistral.engine import default_executor
-from mistral.engine import rpc
+from mistral.engine.rpc import rpc
 from mistral.services import workbooks as wb_service
 from mistral.tests.unit.engine import base
 

mistral/tests/unit/services/test_trigger_service.py

@@ -17,7 +17,7 @@ import eventlet
 import mock
 from oslo_config import cfg
 
-from mistral.engine import rpc
+from mistral.engine.rpc import rpc
 from mistral import exceptions as exc
 from mistral.services import periodic
 from mistral.services import security