deb-mistral/mistral/workflow/utils.py
Renat Akhmerov e2c89f777d Refactoring workflow handler
* Introduced new class Workflow that manages life-cycle of running
  workflows and is responsible for managing workflow persistent state
* Moved all workflow level logic to workflow handler and Workflow class
* Changed semantics if how workflows start errors are handled.
  Previously, in case of invalid user input Mistral engine would store
  information about error in "state_info" field of workflow execution
  and bubble up an exception to the user. This approach was incorrect
  for a number of reasons including broken semantics: if an exception
  was raised due to invalid input it's normal to expect that system
  state has not changed. After this refactoring, engine only raises
  an exception in case of bad user input. That way behavior is
  consistent with the idea of exceptional situations.
* Fixed unit tests in according to the previous point
* Fixed a number of logical issues in tests. For example, in
  test_default_engine.py we expected one type of errors (e.g. env not
  found) but effectively received another one (invalid input).

Partially implements: blueprint mistral-engine-error-handling

Change-Id: I09070411fd833df8284cb80db69b8401a40eb6fe
2016-06-07 18:38:38 +07:00

109 lines
3.1 KiB
Python

# Copyright 2014 - Mirantis, Inc.
# Copyright 2015 - StackStorm, 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.
from mistral.utils import serializers
from mistral.workflow import states
class Result(object):
"""Explicit data structure containing a result of task execution."""
def __init__(self, data=None, error=None):
self.data = data
self.error = error
def __repr__(self):
return 'Result [data=%s, error=%s]' % (
repr(self.data), repr(self.error))
def is_error(self):
return self.error is not None
def is_success(self):
return not self.is_error()
def __eq__(self, other):
return self.data == other.data and self.error == other.error
class ResultSerializer(serializers.Serializer):
def serialize(self, entity):
return {'data': entity.data, 'error': entity.error}
def deserialize(self, entity):
return Result(entity['data'], entity['error'])
def find_task_execution_not_state(wf_ex, task_spec, state):
task_execs = [
t for t in wf_ex.task_executions
if t.name == task_spec.get_name() and t.state != state
]
return task_execs[0] if len(task_execs) > 0 else None
def find_task_execution_with_state(wf_ex, task_spec, state):
task_execs = [
t for t in wf_ex.task_executions
if t.name == task_spec.get_name() and t.state == state
]
return task_execs[0] if len(task_execs) > 0 else None
def find_task_executions_by_name(wf_ex, task_name):
return [t for t in wf_ex.task_executions if t.name == task_name]
def find_task_executions_by_spec(wf_ex, task_spec):
return find_task_executions_by_name(wf_ex, task_spec.get_name())
def find_task_executions_by_specs(wf_ex, task_specs):
res = []
for t_s in task_specs:
res = res + find_task_executions_by_spec(wf_ex, t_s)
return res
def find_task_executions_with_state(wf_ex, state):
return [t for t in wf_ex.task_executions if t.state == state]
def find_running_task_executions(wf_ex):
return find_task_executions_with_state(wf_ex, states.RUNNING)
def find_completed_tasks(wf_ex):
return [
t for t in wf_ex.task_executions if states.is_completed(t.state)
]
def find_successful_task_executions(wf_ex):
return find_task_executions_with_state(wf_ex, states.SUCCESS)
def find_incomplete_task_executions(wf_ex):
return [t for t in wf_ex.task_executions
if not states.is_completed(t.state)]
def find_error_task_executions(wf_ex):
return find_task_executions_with_state(wf_ex, states.ERROR)