Bug 1659415

Description of problem:

Tried to deploy from the GUI: 3 controllers + 1 compute + 1 database role, with no network isolation or any additional features.

The deployment hanged in the end so I ran "openstack overcloud status --plan overcloud" but it hanged too. So I ran the workflow manually:

curl -g -i -X POST https://192.168.24.2:13989/v2/executions -H "User-Agent: openstacksdk/0.17.2 keystoneauth1/3.10.0 python-requests/2.19.1 CPython/2.7.5" -H "X-Auth-Token: $TOKEN" -H "content-type: application/json" -d '{"input": "{\"plan\": \"overcloud\"}", "workflow_name": "tripleo.deployment.v1.get_deployment_status", "description": ""}'

Then I checked the execution status: openstack workflow execution show 18fca**** and saw this traceback:

Traceback (most recent call last):                                                                                               
  File "/usr/lib/python2.7/site-packages/mistral/engine/task_handler.py", line 110, in _on_action_complete         
    task.on_action_complete(action_ex)                                                                                           
  File "/usr/lib/python2.7/site-packages/osprofiler/profiler.py", line 159, in wrapper                             
    result = f(*args, **kwargs)                                                                                                  
  File "/usr/lib/python2.7/site-packages/mistral/engine/tasks.py", line 381, in on_action_complete
    self.complete(state, state_info)                                                                                             
  File "/usr/lib/python2.7/site-packages/osprofiler/profiler.py", line 159, in wrapper       
    result = f(*args, **kwargs)                                                                                                  
  File "/usr/lib/python2.7/site-packages/mistral/engine/tasks.py", line 246, in complete     
    cmds = wf_ctrl.continue_workflow(task_ex=self.task_ex)                                                                       
  File "/usr/lib/python2.7/site-packages/osprofiler/profiler.py", line 159, in wrapper       
    result = f(*args, **kwargs)                                                                                                  
  File "/usr/lib/python2.7/site-packages/mistral/workflow/base.py", line 134, in continue_workflow
    return self._find_next_commands(task_ex)                                                                                     
  File "/usr/lib/python2.7/site-packages/mistral/workflow/direct_workflow.py", line 93, in _find_next_commands
    cmds.extend(self._find_next_commands_for_task(t_ex))                                                                         
  File "/usr/lib/python2.7/site-packages/mistral/workflow/direct_workflow.py", line 120, in _find_next_commands_for_task
    for t_n, params, event_name in self._find_next_tasks(task_ex, ctx=ctx):
  File "/usr/lib/python2.7/site-packages/mistral/workflow/direct_workflow.py", line 284, in _find_next_tasks
    'on-complete'
  File "/usr/lib/python2.7/site-packages/mistral/workflow/direct_workflow.py", line 265, in process_clause
    task_tuples = self._find_next_tasks_for_clause(clause, ctx_view)
  File "/usr/lib/python2.7/site-packages/mistral/workflow/direct_workflow.py", line 308, in _find_next_tasks_for_clause
    if not condition or expr.evaluate(condition, ctx)
  File "/usr/lib/python2.7/site-packages/mistral/expressions/__init__.py", line 71, in evaluate
    return evaluator.evaluate(expression, context)
  File "/usr/lib/python2.7/site-packages/mistral/expressions/yaql_expression.py", line 159, in evaluate
    cls).evaluate(trim_expr, data_context)
  File "/usr/lib/python2.7/site-packages/mistral/expressions/yaql_expression.py", line 113, in evaluate
    ", data=%s]" % (expression, str(e), data_context)
YaqlEvaluationException: Can not evaluate YAQL expression [expression=$.status_update = null and $.deployment_status != null, error=u'status_update', data={}] 


Version-Release number of selected component (if applicable):
openstack-tripleo-common-9.4.1-0.20181012010884.el7ost.noarch
openstack-mistral-executor:2018-12-11.1
openstack-mistral-engine:2018-12-11.1
openstack-mistral-api:2018-12-11.1 


How reproducible:
100%


Steps to Reproduce:
1. Start a deployment: 3 controllers + 1 compute + 1 database role, with no network isolation or any additional features.
2. Run "openstack overcloud status --plan overcloud". It should hang.
3. Run the workflow manually: openstack workflow execution create tripleo.deployment.v1.get_deployment_status '{"plan": "overcloud"}'
4. Check if the execution finished: openstack workflow execution show <<ID>>


Actual results:
YaqlEvaluationException: Can not evaluate YAQL expression [expression=$.status_update = null and $.deployment_status != null, error=u'status_update', data={}]


Expected results:
The workflow should return the deployment status