JavaScript action: part 1

* Added new action - std.javascript
 * Use V8 JS engine for now
 * Allow to use any JS engine in future

TODO (next commit):
 * Add guide on how install PyV8
 * Work with data context in JS action

Partially implements blueprint mistral-javascript-action

Change-Id: I5bd940e75f5224d813c9cd865f9411e90bec09c1

mistral/actions/std_actions.py

@@ -23,6 +23,7 @@ import smtplib
 from mistral.actions import base
 from mistral import exceptions as exc
 from mistral.openstack.common import log as logging
+from mistral.utils import javascript
 from mistral.utils import ssh_utils
 
 
@@ -326,3 +327,20 @@ class SSHAction(base.Action):
     def test(self):
         # TODO(rakhmerov): Implement.
         return None
+
+
+class JavaScriptAction(base.Action):
+    """Evaluates given JavaScript.
+
+    """
+    def __init__(self, script):
+        self.script = script
+
+    def run(self):
+        try:
+            return javascript.evaluate(self.script)
+        except Exception as e:
+            raise exc.ActionException("JavaScriptAction failed: %s" % str(e))
+
+    def test(self):
+        return self.script

mistral/tests/unit/actions/test_action_factory.py

@@ -93,6 +93,7 @@ class ActionFactoryTest(base.DbTestCase):
         self._assert_single_item(action_list, name="std.http")
         self._assert_single_item(action_list, name="std.mistral_http")
         self._assert_single_item(action_list, name="std.ssh")
+        self._assert_single_item(action_list, name="std.javascript")
 
         self._assert_single_item(action_list, name="nova.servers_get")
         self._assert_single_item(action_list, name="nova.volumes_delete")
@@ -110,6 +111,8 @@ class ActionFactoryTest(base.DbTestCase):
                          a_m.get_action_class("std.mistral_http"))
         self.assertEqual(std.SendEmailAction,
                          a_m.get_action_class("std.email"))
+        self.assertEqual(std.JavaScriptAction,
+                         a_m.get_action_class("std.javascript"))
 
     def test_resolve_adhoc_action_name(self):
         wb = spec_parser.get_workbook_spec_from_yaml(

mistral/tests/unit/actions/test_javascript_action.py

@@ -0,0 +1,28 @@
+# 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 mock
+
+from mistral.actions import std_actions as std
+from mistral.tests import base
+from mistral.utils import javascript
+
+
+class JavascriptActionTest(base.BaseTest):
+    @mock.patch.object(javascript, 'evaluate', mock.Mock(return_value="3"))
+    def test_js_action(self):
+        script = "1 + 2"
+        action = std.JavaScriptAction(script)
+
+        self.assertEqual("3", action.run())

mistral/utils/javascript.py

@@ -0,0 +1,47 @@
+# 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 abc
+
+from mistral import exceptions as exc
+from mistral.openstack.common import importutils
+
+
+_PYV8 = importutils.try_import('PyV8')
+
+
+class JSEvaluator(object):
+    @classmethod
+    @abc.abstractmethod
+    def evaluate(cls, script):
+        pass
+
+
+class V8Evaluator(JSEvaluator):
+    @classmethod
+    def evaluate(cls, script):
+        if not _PYV8:
+            raise exc.MistralException(
+                "PyV8 module is not available. Please install PyV8."
+            )
+
+        with _PYV8.JSContext() as ctx:
+            return ctx.eval(script)
+
+# TODO(nmakhotkin) Make it configurable.
+EVALUATOR = V8Evaluator
+
+
+def evaluate(script):
+    return EVALUATOR.evaluate(script)

setup.cfg

@@ -48,3 +48,4 @@ mistral.actions =
     std.mistral_http = mistral.actions.std_actions:MistralHTTPAction
     std.ssh = mistral.actions.std_actions:SSHAction
     std.email = mistral.actions.std_actions:SendEmailAction
+    std.javascript = mistral.actions.std_actions:JavaScriptAction