deb-mistral/mistral/utils/expression_utils.py
Renat Akhmerov 422def65a8 Change task() function to return 'null' if task doesn't exist
* Before this change function task(task_name) available in Mistral
  expressions would fail with an error if such task doesn't exist.
  It makes impossible to have expressions like <% task(t1) != null %>
  which is very convenient in cases when we need to gather meta
  info about how a workflow was running and what tasks have already
  started and what have not. So now it simply returns 'null'.

Change-Id: Ifd1ea9b5ee946c7072044d1402296710676845db
Closes-Bug: #1631035
2016-10-07 15:28:45 +07:00

158 lines
4.3 KiB
Python

# Copyright 2015 - Mirantis, Inc.
# Copyright 2016 - Brocade Communications Systems, 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 functools import partial
from oslo_serialization import jsonutils
from stevedore import extension
import yaql
from mistral.db.v2 import api as db_api
from mistral import utils
ROOT_YAQL_CONTEXT = None
def get_yaql_context(data_context):
global ROOT_YAQL_CONTEXT
if not ROOT_YAQL_CONTEXT:
ROOT_YAQL_CONTEXT = yaql.create_context()
_register_yaql_functions(ROOT_YAQL_CONTEXT)
new_ctx = ROOT_YAQL_CONTEXT.create_child_context()
new_ctx['$'] = data_context
if isinstance(data_context, dict):
new_ctx['__env'] = data_context.get('__env')
new_ctx['__execution'] = data_context.get('__execution')
new_ctx['__task_execution'] = data_context.get('__task_execution')
return new_ctx
def get_jinja_context(data_context):
new_ctx = {
'_': data_context
}
_register_jinja_functions(new_ctx)
if isinstance(data_context, dict):
new_ctx['__env'] = data_context.get('__env')
new_ctx['__execution'] = data_context.get('__execution')
new_ctx['__task_execution'] = data_context.get('__task_execution')
return new_ctx
def get_custom_functions():
"""Get custom functions
Retreives the list of custom evaluation functions
"""
functions = dict()
mgr = extension.ExtensionManager(
namespace='mistral.expression.functions',
invoke_on_load=False
)
for name in mgr.names():
functions[name] = mgr[name].plugin
return functions
def _register_yaql_functions(yaql_ctx):
functions = get_custom_functions()
for name in functions:
yaql_ctx.register_function(functions[name], name=name)
def _register_jinja_functions(jinja_ctx):
functions = get_custom_functions()
for name in functions:
jinja_ctx[name] = partial(functions[name], jinja_ctx['_'])
# Additional YAQL functions needed by Mistral.
# If a function name ends with underscore then it doesn't need to pass
# the name of the function when context registers it.
def env_(context):
return context['__env']
def execution_(context):
wf_ex = db_api.get_workflow_execution(context['__execution']['id'])
return {
'id': wf_ex.id,
'name': wf_ex.name,
'spec': wf_ex.spec,
'input': wf_ex.input,
'params': wf_ex.params
}
def json_pp_(context, data=None):
return jsonutils.dumps(
data or context,
indent=4
).replace("\\n", "\n").replace(" \n", "\n")
def task_(context, task_name):
# Importing data_flow in order to break cycle dependency between modules.
from mistral.workflow import data_flow
# This section may not exist in a context if it's calculated not in
# task scope.
cur_task = context['__task_execution']
if cur_task and cur_task['name'] == task_name:
task_ex = db_api.get_task_execution(cur_task['id'])
else:
task_execs = db_api.get_task_executions(
workflow_execution_id=context['__execution']['id'],
name=task_name
)
# TODO(rakhmerov): Account for multiple executions (i.e. in case of
# cycles).
task_ex = task_execs[-1] if len(task_execs) > 0 else None
if not task_ex:
return None
# We don't use to_dict() db model method because not all fields
# make sense for user.
return {
'id': task_ex.id,
'name': task_ex.name,
'spec': task_ex.spec,
'state': task_ex.state,
'state_info': task_ex.state_info,
'result': data_flow.get_task_execution_result(task_ex),
'published': task_ex.published
}
def uuid_(context=None):
return utils.generate_unicode_uuid()