Add 'uuid' YAQL function

Change-Id: I34098a72a098c460f6352344b7797edde1e604a6

mistral/tests/unit/engine/test_yaql_functions.py

@@ -132,3 +132,34 @@ class YAQLFunctionsEngineTest(engine_test_base.EngineTestCase):
 
         self.assertEqual(states.ERROR, wf_ex.state)
         self.assertIn('non_existing_task', wf_ex.state_info)
+
+    def test_uuid_function(self):
+        wf_text = """---
+            version: '2.0'
+
+            wf:
+              tasks:
+                task1:
+                  action: std.echo output=<% uuid() %>
+                  publish:
+                    result: <% task(task1).result %>
+            """
+
+        wf_service.create_workflows(wf_text)
+
+        wf_ex = self.engine.start_workflow('wf', {})
+
+        self.await_workflow_success(wf_ex.id)
+
+        with db_api.transaction():
+            wf_ex = db_api.get_workflow_execution(wf_ex.id)
+
+            task_execs = wf_ex.task_executions
+
+        task_ex = task_execs[0]
+
+        result = task_ex.published['result']
+
+        self.assertIsNotNone(result)
+        self.assertEqual(36, len(result))
+        self.assertEqual(4, result.count('-'))

mistral/utils/yaql_utils.py

@@ -16,6 +16,7 @@
 import yaql
 
 from mistral.db.v2 import api as db_api
+from mistral import utils
 from mistral.workflow import utils as wf_utils
 from oslo_serialization import jsonutils
 from stevedore import extension
@@ -107,3 +108,7 @@ def task_(context, task_name):
         'result': data_flow.get_task_execution_result(task_ex),
         'published': task_ex.published
     }
+
+
+def uuid_(context):
+    return utils.generate_unicode_uuid()

setup.cfg

@@ -74,3 +74,4 @@ mistral.yaql_functions =
     task = mistral.utils.yaql_utils:task_
     execution = mistral.utils.yaql_utils:execution_
     env = mistral.utils.yaql_utils:env_
+    uuid = mistral.utils.yaql_utils:uuid_