# Buggy code
def __init__(self, parent, policy_json=None):
    super(ExecutablePolicyRule, self).__init__(parent, policy_json)

    # Configure the trigger instance
    try:
        self.gate_cls = Gate.get_gate_by_name(self.gate_name)
    except KeyError:
        # Gate not found
        self.error_exc = GateNotFoundError(
            gate=self.gate_name,
            valid_gates=Gate.registered_gate_names(),
            rule_id=self.rule_id,
        )
        self.configured_trigger = None
        raise self.error_exc

    try:
        selected_trigger_cls = self.gate_cls.get_trigger_named(
            self.trigger_name.lower()
        )
    except KeyError:
        self.error_exc = TriggerNotFoundError(
            valid_triggers=self.gate_cls.trigger_names(),
            trigger=self.trigger_name,
            gate=self.gate_name,
            rule_id=self.rule_id,
        )
        self.configured_trigger = None
        raise self.error_exc

    try:
        try:
            self.configured_trigger = selected_trigger_cls(
                parent_gate_cls=self.gate_cls,
                rule_id=self.rule_id,
                **self.trigger_params,
            )
        except [
            TriggerNotFoundError,
            InvalidParameterError,
            ParameterValueInvalidError,
        ] as e:
            # Error finding or initializing the trigger
            log.exception("Policy rule execution exception: {}".format(e))
            self.error_exc = e
            self.configured_trigger = None

            if hasattr(e, "gate") and e.gate is None:
                e.gate = self.gate_name
            if hasattr(e, "trigger") and e.trigger is None:
                e.trigger = self.trigger_name
            if hasattr(e, "rule_id") and e.rule_id is None:
                e.rule_id = self.rule_id
            raise e
    except PolicyError:
        raise  # To filter out already-handled errors
    except Exception as e:
        raise ValidationError.caused_by(e)


# Traceback (ValueError)
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-] Traceback (most recent call last):
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-]   File "/usr/local/lib/python3.6/dist-packages/anchore_engine/services/policy_engine/engine/policy/gate.py", line 234, in execute
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-]     self.evaluate(image_obj, context)
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-]   File "/usr/local/lib/python3.6/dist-packages/anchore_engine/services/policy_engine/engine/policy/gates/image_metadata.py", line 59, in evaluate
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-]     rval = type(img_val)(rval)
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-] ValueError: invalid literal for int() with base 10: '4gb'
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-]
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-] During handling of the above exception, another exception occurred:
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-]
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-] Traceback (most recent call last):
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-]   File "/usr/local/lib/python3.6/dist-packages/anchore_engine/services/policy_engine/engine/policy/bundles.py", line 453, in execute
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-]     self.configured_trigger.execute(image_obj, exec_context)
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-]   File "/usr/local/lib/python3.6/dist-packages/anchore_engine/services/policy_engine/engine/policy/gate.py", line 237, in execute
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-]     raise TriggerEvaluationError(trigger=self, message='Error executing gate {} trigger {} with params: {}. Msg: {}'.format(self.gate_cls.__gate_name__, self.__trigger_name__, self.eval_params, e.message))
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-] AttributeError: 'ValueError' object has no attribute 'message'
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-]
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-] During handling of the above exception, another exception occurred:
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-]
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-] Traceback (most recent call last):
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-]   File "/usr/local/lib/python3.6/dist-packages/anchore_engine/services/policy_engine/api/controllers/synchronous_operations.py", line 481, in check_user_image_inline
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-]     eval_result = executable_bundle.execute(img_obj, tag, ExecutionContext(db_session=db, configuration={}))
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-]   File "/usr/local/lib/python3.6/dist-packages/anchore_engine/services/policy_engine/engine/policy/bundles.py", line 1260, in execute
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-]     bundle_exec = self._process_mapping_result(bundle_exec, image_object, tag, context)
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-]   File "/usr/local/lib/python3.6/dist-packages/anchore_engine/services/policy_engine/engine/policy/bundles.py", line 1207, in _process_mapping_result
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-]     errors, policy_decision = evaluated_policy.execute(image_obj=image_object, context=context)
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-]   File "/usr/local/lib/python3.6/dist-packages/anchore_engine/services/policy_engine/engine/policy/bundles.py", line 596, in execute
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-]     errs, matches = rule.execute(image_obj=image_obj, exec_context=exec_context)
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-]   File "/usr/local/lib/python3.6/dist-packages/anchore_engine/services/policy_engine/engine/policy/bundles.py", line 458, in execute
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-]     raise TriggerEvaluationError(trigger=self.configured_trigger, message='Could not evaluate trigger due to error in evaluation execution')
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-] anchore_engine.services.policy_engine.engine.policy.exceptions.TriggerEvaluationError: TriggerEvaluationError: severity:error message:Trigger evaluation failed for gate metadata and trigger attribute, with parameters: ([]) due to: Could not evaluate trigger due to error in evaluation execution
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-]
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-] During handling of the above exception, another exception occurred:
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-]
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-] Traceback (most recent call last):
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-]   File "/usr/local/lib/python3.6/dist-packages/anchore_engine/apis/authorization.py", line 339, in inner_wrapper
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-]     return f(*args, **kwargs)
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-]   File "/usr/local/lib/python3.6/dist-packages/anchore_engine/services/policy_engine/api/controllers/synchronous_operations.py", line 484, in check_user_image_inline
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-]     abort(Response(response='Cannot execute given policy against the image due to errors executing the policy bundle: {}'.format(e.message), status=500))
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-]   File "/usr/local/lib/python3.6/dist-packages/werkzeug/exceptions.py", line 707, in abort
engine-policy-engine_1  | [service:policy-engine] 2019-01-11 05:49:12+0000 [-]     return _aborter(status, *args, **kwargs)

# Fixed code
def __init__(self, parent, policy_json=None):
    super(ExecutablePolicyRule, self).__init__(parent, policy_json)

    # Configure the trigger instance
    try:
        self.gate_cls = Gate.get_gate_by_name(self.gate_name)
    except KeyError:
        # Gate not found
        self.error_exc = GateNotFoundError(
            gate=self.gate_name,
            valid_gates=Gate.registered_gate_names(),
            rule_id=self.rule_id,
        )
        self.configured_trigger = None
        raise self.error_exc

    try:
        selected_trigger_cls = self.gate_cls.get_trigger_named(
            self.trigger_name.lower()
        )
    except KeyError:
        self.error_exc = TriggerNotFoundError(
            valid_triggers=self.gate_cls.trigger_names(),
            trigger=self.trigger_name,
            gate=self.gate_name,
            rule_id=self.rule_id,
        )
        self.configured_trigger = None
        raise self.error_exc

    try:
        try:
            self.configured_trigger = selected_trigger_cls(
                parent_gate_cls=self.gate_cls,
                rule_id=self.rule_id,
                **self.trigger_params,
            )
        except (
            TriggerNotFoundError,
            InvalidParameterError,
            ParameterValueInvalidError,
        ) as e:
            # Error finding or initializing the trigger
            self.error_exc = e
            self.configured_trigger = None

            if hasattr(e, "gate") and e.gate is None:
                e.gate = self.gate_name
            if hasattr(e, "trigger") and e.trigger is None:
                e.trigger = self.trigger_name
            if hasattr(e, "rule_id") and e.rule_id is None:
                e.rule_id = self.rule_id
            raise e
    except PolicyError:
        raise  # To filter out already-handled errors
    except Exception as e:
        raise ValidationError.caused_by(e)