Add DSL parser

* DSL parser
 * Unit tests

Change-Id: I3e56ad7125233ecdafd41036d8b717fb95e2955c

mistral/dsl.py

@@ -0,0 +1,53 @@
+# Copyright (c) 2013 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 yaml
+from yaml import error
+
+
+class Parser(object):
+    """Mistral DSL parser.
+
+    Loads a workbook definition in YAML format as described in Mistral DSL
+    specification and provides various methods to access DSL entities like
+    tasks and actions in a form of dictionary.
+    """
+    def __init__(self, workbook_definition):
+        try:
+            self.doc = yaml.safe_load(workbook_definition)
+        except error.YAMLError as exc:
+            raise RuntimeError("Definition could not be parsed: %s\n"
+                               % exc.message)
+
+    def get_service(self):
+        return self.doc["Service"]
+
+    def get_events(self):
+        events_from_doc = self.doc["Workflow"]["events"]
+        events = []
+        for name in events_from_doc:
+            event_dict = {'name': name}
+            event_dict.update(events_from_doc[name])
+            events.append(event_dict)
+        return events
+
+    def get_tasks(self):
+        return self.doc["Workflow"]["tasks"]
+
+    def get_service_name(self):
+        return self.doc['Service']['name']
+
+    def get_event_task_name(self, event_name):
+        return self.doc["Workflow"]["events"][event_name]['tasks']

mistral/tests/resources/test_rest.yaml

@@ -0,0 +1,76 @@
+Service:
+   name: MyRest
+   type: REST_API
+   parameters:
+       baseUrl: http://some_host
+   actions:
+       create-vm:
+         parameters:
+             url: /service/action/execute
+             method: GET
+         task-parameters:
+            flavor_id:
+              optional: false
+            image_id:
+              optional: false
+       backup-vm:
+         parameters:
+             url: url_for_backup
+             method: GET
+         task-parameters:
+             server_id:
+               optional: false
+       attach-volume:
+         parameters:
+             url: url_for_attach
+             method: GET
+         task-parameters:
+             size:
+               optional: false
+             mnt_path:
+               optional: false
+       format-volume:
+         parameters:
+             url: url_for_format
+             method: GET
+         task-parameters:
+             volume_id:
+               optional: false
+             server_id:
+               optional: false
+
+
+Workflow:
+   tasks:
+     create-vms:
+         action: MyRest:create-vm
+         parameters:
+           image_id: 1234
+           flavor_id: 42
+
+     attach-volumes:
+         action: Nova:attach-volume
+         parameters:
+           size:
+             optional: false
+           mnt_path:
+             optional: false
+         dependsOn: [create-vms]
+     format-volumes:
+        action: Nova:format-volume
+        parameters:
+           server_id:
+             optional: false
+        dependsOn: [attach-volumes]
+     backup-vms:
+        action: Nova:backup-vm
+        parameters:
+           server_id:
+             optional: false
+        dependsOn: [create-vms]
+   events:
+     create-vms:
+        type: periodic
+        tasks: create-vms
+        parameters:
+            cron-pattern: "* * * * *"

mistral/tests/unit/test_parser.py

@@ -0,0 +1,54 @@
+# Copyright (c) 2013 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 pkg_resources as pkg
+import unittest2
+
+from mistral import dsl
+from mistral import version
+
+
+class DSLParserTest(unittest2.TestCase):
+    def setUp(self):
+        doc = open(pkg.resource_filename(
+            version.version_info.package,
+            "tests/resources/test_rest.yaml")).read()
+        self.dsl = dsl.Parser(doc)
+
+    def test_service(self):
+        service = self.dsl.get_service()
+        self.assertEqual(service["name"], "MyRest")
+        self.assertEqual(service["type"], "REST_API")
+        self.assertIn("baseUrl", service["parameters"])
+
+    def test_events(self):
+        events = self.dsl.get_events()
+        self.assertIn("create-vms", events[0]['name'])
+
+    def test_tasks(self):
+        tasks = self.dsl.get_tasks()
+        self.assertIn("create-vms", tasks)
+        self.assertIn("parameters", tasks["create-vms"])
+        self.assertEqual(tasks["backup-vms"]["action"],
+                         "Nova:backup-vm")
+
+    def test_broken_definition(self):
+        broken_yaml = """
+        Workflow:
+          [tasks:
+            create-vms/:
+
+        """
+        self.assertRaises(RuntimeError, dsl.Parser, broken_yaml)

mistral/version.py

@@ -15,5 +15,5 @@
 
 from pbr import version
 
-version_info = version.VersionInfo('Mistral')
+version_info = version.VersionInfo('mistral')
 version_string = version_info.version_string