st2kv inside the rules criteria is not working

Hi ,

I am trying to retreive datastore value inside the criteria of the rules as like below.

Yaml:

name: ticket-to-stackstorm-rule
pack: avmarmusecase
enabled: true
trigger:
  type: "default.workflowinitiate"
criteria:
  trigger.category:
    pattern: "{{st2kv.system.db}}"
    type: "equals"
  trigger.item:
    pattern: "Policy_Update"
    type: "equals"

Error Log:

Traceback (most recent call last):
  File "/opt/stackstorm/st2/local/lib/python2.7/site-packages/st2reactor/rules/filter.py", line 118, in _check_criterion
    criteria_context=payload_lookup.context
  File "/opt/stackstorm/st2/local/lib/python2.7/site-packages/st2reactor/rules/filter.py", line 189, in _render_criteria_pattern
    context=criteria_context
  File "/opt/stackstorm/st2/local/lib/python2.7/site-packages/st2common/util/templating.py", line 86, in render_template_with_system_context
    rendered = render_template(value=value, context=context)
  File "/opt/stackstorm/st2/local/lib/python2.7/site-packages/st2common/util/templating.py", line 53, in render_template
    rendered = template.render(context)
  File "/opt/stackstorm/st2/local/lib/python2.7/site-packages/jinja2/environment.py", line 1008, in render
    return self.environment.handle_exception(exc_info, True)
  File "/opt/stackstorm/st2/local/lib/python2.7/site-packages/jinja2/environment.py", line 780, in handle_exception
    reraise(exc_type, exc_value, tb)
  File "<template>", line 1, in top-level template code
  File "/opt/stackstorm/st2/local/lib/python2.7/site-packages/st2common/jinja/filters/complex_type.py", line 24, in to_complex
    result = json.dumps(value)
  File "/usr/lib/python2.7/json/__init__.py", line 243, in dumps
    return _default_encoder.encode(obj)
  File "/usr/lib/python2.7/json/encoder.py", line 207, in encode
    chunks = self.iterencode(o, _one_shot=True)
  File "/usr/lib/python2.7/json/encoder.py", line 270, in iterencode
    return _iterencode(o, 0)
  File "/usr/lib/python2.7/json/encoder.py", line 184, in default
    raise TypeError(repr(o) + " is not JSON serializable")

Please help on this issue.

Thanks
Arul

Start in st2reactor/rules/filter.py at _check_criterion and _render_criteria_pattern, then follow the call into st2common/util/templating.py and the complex_type filter shown in the traceback. Reproduce the supplied rule and datastore expression to determine why rendering fails. Done means the criteria can retrieve the datastore value without the JSON serialization error and the behavior is covered by an appropriate regression test.