544 lines
16 KiB
Python
544 lines
16 KiB
Python
# Copyright 2016 - Nokia Networks.
|
|
# 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.
|
|
|
|
import abc
|
|
import operator
|
|
from oslo_log import log as logging
|
|
from osprofiler import profiler
|
|
import six
|
|
|
|
from mistral.db.v2 import api as db_api
|
|
from mistral.engine import actions
|
|
from mistral.engine import dispatcher
|
|
from mistral.engine import policies
|
|
from mistral import exceptions as exc
|
|
from mistral import expressions as expr
|
|
from mistral import utils
|
|
from mistral.utils import wf_trace
|
|
from mistral.workflow import base as wf_base
|
|
from mistral.workflow import data_flow
|
|
from mistral.workflow import states
|
|
from mistral.workflow import with_items
|
|
|
|
|
|
LOG = logging.getLogger(__name__)
|
|
|
|
|
|
@six.add_metaclass(abc.ABCMeta)
|
|
class Task(object):
|
|
"""Task.
|
|
|
|
Represents a workflow task and defines interface that can be used by
|
|
Mistral engine or its components in order to manipulate with tasks.
|
|
"""
|
|
|
|
@profiler.trace('task-create')
|
|
def __init__(self, wf_ex, wf_spec, task_spec, ctx, task_ex=None,
|
|
unique_key=None, waiting=False):
|
|
self.wf_ex = wf_ex
|
|
self.task_spec = task_spec
|
|
self.ctx = ctx
|
|
self.task_ex = task_ex
|
|
self.wf_spec = wf_spec
|
|
self.unique_key = unique_key
|
|
self.waiting = waiting
|
|
self.reset_flag = False
|
|
self.created = False
|
|
self.state_changed = False
|
|
|
|
def is_completed(self):
|
|
return self.task_ex and states.is_completed(self.task_ex.state)
|
|
|
|
def is_waiting(self):
|
|
return self.waiting
|
|
|
|
def is_created(self):
|
|
return self.created
|
|
|
|
def is_state_changed(self):
|
|
return self.state_changed
|
|
|
|
@abc.abstractmethod
|
|
def on_action_complete(self, action_ex):
|
|
"""Handle action completion.
|
|
|
|
:param action_ex: Action execution.
|
|
"""
|
|
raise NotImplementedError
|
|
|
|
@abc.abstractmethod
|
|
def run(self):
|
|
"""Runs task."""
|
|
raise NotImplementedError
|
|
|
|
@profiler.trace('task-defer')
|
|
def defer(self):
|
|
"""Defers task.
|
|
|
|
This method puts task to a waiting state.
|
|
"""
|
|
with db_api.named_lock(self.unique_key):
|
|
if not self.task_ex:
|
|
t_execs = db_api.get_task_executions(
|
|
workflow_execution_id=self.wf_ex.id,
|
|
unique_key=self.unique_key
|
|
)
|
|
|
|
self.task_ex = t_execs[0] if t_execs else None
|
|
|
|
msg = 'Task is waiting.'
|
|
|
|
if not self.task_ex:
|
|
self._create_task_execution(
|
|
state=states.WAITING,
|
|
state_info=msg
|
|
)
|
|
elif self.task_ex.state != states.WAITING:
|
|
self.set_state(states.WAITING, msg)
|
|
|
|
def reset(self):
|
|
self.reset_flag = True
|
|
|
|
@profiler.trace('task-set-state')
|
|
def set_state(self, state, state_info, processed=None):
|
|
"""Sets task state without executing post completion logic.
|
|
|
|
:param state: New task state.
|
|
:param state_info: New state information (i.e. error message).
|
|
:param processed: New "processed" flag value.
|
|
"""
|
|
|
|
assert self.task_ex
|
|
|
|
if (self.task_ex.state != state or
|
|
self.task_ex.state_info != state_info):
|
|
wf_trace.info(
|
|
self.task_ex.workflow_execution,
|
|
"Task '%s' (%s) [%s -> %s, msg=%s]" %
|
|
(self.task_ex.name,
|
|
self.task_ex.id,
|
|
self.task_ex.state,
|
|
state,
|
|
state_info)
|
|
)
|
|
|
|
self.state_changed = True
|
|
|
|
self.task_ex.state = state
|
|
self.task_ex.state_info = state_info
|
|
|
|
if processed is not None:
|
|
self.task_ex.processed = processed
|
|
|
|
@profiler.trace('task-complete')
|
|
def complete(self, state, state_info=None):
|
|
"""Complete task and set specified state.
|
|
|
|
Method sets specified task state and runs all necessary post
|
|
completion logic such as publishing workflow variables and
|
|
scheduling new workflow commands.
|
|
|
|
:param state: New task state.
|
|
:param state_info: New state information (i.e. error message).
|
|
"""
|
|
|
|
assert self.task_ex
|
|
|
|
# Ignore if task already completed.
|
|
if states.is_completed(self.task_ex.state):
|
|
return
|
|
|
|
self.set_state(state, state_info)
|
|
|
|
data_flow.publish_variables(self.task_ex, self.task_spec)
|
|
|
|
if not self.task_spec.get_keep_result():
|
|
# Destroy task result.
|
|
for ex in self.task_ex.action_executions:
|
|
if hasattr(ex, 'output'):
|
|
ex.output = {}
|
|
|
|
self._after_task_complete()
|
|
|
|
# Ignore DELAYED state.
|
|
if self.task_ex.state == states.RUNNING_DELAYED:
|
|
return
|
|
|
|
# If workflow is paused we shouldn't schedule new commands
|
|
# and mark task as processed.
|
|
if states.is_paused(self.wf_ex.state):
|
|
return
|
|
|
|
wf_ctrl = wf_base.get_controller(self.wf_ex, self.wf_spec)
|
|
|
|
# Calculate commands to process next.
|
|
cmds = wf_ctrl.continue_workflow(task_ex=self.task_ex)
|
|
|
|
# Mark task as processed after all decisions have been made
|
|
# upon its completion.
|
|
self.task_ex.processed = True
|
|
|
|
dispatcher.dispatch_workflow_commands(self.wf_ex, cmds)
|
|
|
|
def _before_task_start(self):
|
|
policies_spec = self.task_spec.get_policies()
|
|
|
|
for p in policies.build_policies(policies_spec, self.wf_spec):
|
|
p.before_task_start(self.task_ex, self.task_spec)
|
|
|
|
def _after_task_complete(self):
|
|
policies_spec = self.task_spec.get_policies()
|
|
|
|
for p in policies.build_policies(policies_spec, self.wf_spec):
|
|
p.after_task_complete(self.task_ex, self.task_spec)
|
|
|
|
def _create_task_execution(self, state=states.RUNNING, state_info=None):
|
|
task_id = utils.generate_unicode_uuid()
|
|
task_name = self.task_spec.get_name()
|
|
|
|
data_flow.add_current_task_to_context(self.ctx, task_id, task_name)
|
|
|
|
values = {
|
|
'id': task_id,
|
|
'name': task_name,
|
|
'workflow_execution_id': self.wf_ex.id,
|
|
'workflow_name': self.wf_ex.workflow_name,
|
|
'workflow_id': self.wf_ex.workflow_id,
|
|
'state': state,
|
|
'state_info': state_info,
|
|
'spec': self.task_spec.to_dict(),
|
|
'unique_key': self.unique_key,
|
|
'in_context': self.ctx,
|
|
'published': {},
|
|
'runtime_context': {},
|
|
'project_id': self.wf_ex.project_id
|
|
}
|
|
|
|
self.task_ex = db_api.create_task_execution(values)
|
|
|
|
# Add to collection explicitly so that it's in a proper
|
|
# state within the current session.
|
|
self.wf_ex.task_executions.append(self.task_ex)
|
|
|
|
self.created = True
|
|
|
|
def _get_action_defaults(self):
|
|
action_name = self.task_spec.get_action_name()
|
|
|
|
if not action_name:
|
|
return {}
|
|
|
|
env = self.wf_ex.context.get('__env', {})
|
|
|
|
return env.get('__actions', {}).get(action_name, {})
|
|
|
|
|
|
class RegularTask(Task):
|
|
"""Regular task.
|
|
|
|
Takes care of processing regular tasks with one action.
|
|
"""
|
|
|
|
@profiler.trace('regular-task-on-action-complete')
|
|
def on_action_complete(self, action_ex):
|
|
state = action_ex.state
|
|
# TODO(rakhmerov): Here we can define more informative messages
|
|
# cases when action is successful and when it's not. For example,
|
|
# in state_info we can specify the cause action.
|
|
state_info = (None if state == states.SUCCESS
|
|
else action_ex.output.get('result'))
|
|
|
|
self.complete(state, state_info)
|
|
|
|
@profiler.trace('task-run')
|
|
def run(self):
|
|
if not self.task_ex:
|
|
self._run_new()
|
|
else:
|
|
self._run_existing()
|
|
|
|
def _run_new(self):
|
|
if self.waiting:
|
|
self.defer()
|
|
|
|
return
|
|
|
|
self._create_task_execution()
|
|
|
|
LOG.debug(
|
|
'Starting task [workflow=%s, task_spec=%s, init_state=%s]' %
|
|
(self.wf_ex.name, self.task_spec, self.task_ex.state)
|
|
)
|
|
|
|
self._before_task_start()
|
|
|
|
# Policies could possibly change task state.
|
|
if self.task_ex.state != states.RUNNING:
|
|
return
|
|
|
|
self._schedule_actions()
|
|
|
|
def _run_existing(self):
|
|
if self.waiting:
|
|
return
|
|
|
|
# Explicitly change task state to RUNNING.
|
|
# Throw exception if the existing task already succeeded.
|
|
if self.task_ex.state == states.SUCCESS:
|
|
raise exc.MistralError(
|
|
'Rerunning succeeded tasks is not supported.'
|
|
)
|
|
|
|
self.set_state(states.RUNNING, None, processed=False)
|
|
|
|
self._update_inbound_context()
|
|
self._reset_actions()
|
|
self._schedule_actions()
|
|
|
|
def _update_inbound_context(self):
|
|
assert self.task_ex
|
|
|
|
wf_ctrl = wf_base.get_controller(self.wf_ex, self.wf_spec)
|
|
|
|
self.ctx = wf_ctrl.get_task_inbound_context(self.task_spec)
|
|
utils.update_dict(self.task_ex.in_context, self.ctx)
|
|
|
|
def _reset_actions(self):
|
|
"""Resets task state.
|
|
|
|
Depending on task type this method may reset task state. For example,
|
|
delete all task actions etc.
|
|
"""
|
|
|
|
# Reset state of processed task and related action executions.
|
|
if self.reset_flag:
|
|
execs = self.task_ex.executions
|
|
else:
|
|
execs = filter(
|
|
lambda e: e.accepted and e.state == states.ERROR,
|
|
self.task_ex.executions
|
|
)
|
|
|
|
for ex in execs:
|
|
ex.accepted = False
|
|
|
|
def _schedule_actions(self):
|
|
# Regular task schedules just one action.
|
|
input_dict = self._get_action_input()
|
|
target = self._get_target(input_dict)
|
|
|
|
action = self._build_action()
|
|
|
|
action.validate_input(input_dict)
|
|
|
|
action.schedule(
|
|
input_dict,
|
|
target,
|
|
safe_rerun=self.task_spec.get_safe_rerun()
|
|
)
|
|
|
|
def _get_target(self, input_dict):
|
|
ctx_view = data_flow.ContextView(
|
|
input_dict,
|
|
self.ctx,
|
|
self.wf_ex.context,
|
|
self.wf_ex.input
|
|
)
|
|
|
|
return expr.evaluate_recursively(
|
|
self.task_spec.get_target(),
|
|
ctx_view
|
|
)
|
|
|
|
def _get_action_input(self, ctx=None):
|
|
ctx = ctx or self.ctx
|
|
|
|
ctx_view = data_flow.ContextView(
|
|
ctx,
|
|
self.wf_ex.context,
|
|
self.wf_ex.input
|
|
)
|
|
|
|
input_dict = expr.evaluate_recursively(
|
|
self.task_spec.get_input(),
|
|
ctx_view
|
|
)
|
|
|
|
return utils.merge_dicts(
|
|
input_dict,
|
|
self._get_action_defaults(),
|
|
overwrite=False
|
|
)
|
|
|
|
def _build_action(self):
|
|
action_name = self.task_spec.get_action_name()
|
|
wf_name = self.task_spec.get_workflow_name()
|
|
|
|
if wf_name:
|
|
return actions.WorkflowAction(wf_name, task_ex=self.task_ex)
|
|
|
|
if not action_name:
|
|
action_name = 'std.noop'
|
|
|
|
action_def = actions.resolve_action_definition(
|
|
action_name,
|
|
self.wf_ex.name,
|
|
self.wf_spec.get_name()
|
|
)
|
|
|
|
if action_def.spec:
|
|
return actions.AdHocAction(action_def, task_ex=self.task_ex)
|
|
|
|
return actions.PythonAction(action_def, task_ex=self.task_ex)
|
|
|
|
|
|
# TODO(rakhmerov): Concurrency support is currently dropped since it doesn't
|
|
# fit into non-locking transactional model. It needs to be restored later on.
|
|
# A possible solution should be able to read and write a number of currently
|
|
# running actions atomically which is now impossible w/o locks with JSON
|
|
# field "runtime_context".
|
|
class WithItemsTask(RegularTask):
|
|
"""With-items task.
|
|
|
|
Takes care of processing "with-items" tasks.
|
|
"""
|
|
|
|
@profiler.trace('with-items-task-on-action-complete')
|
|
def on_action_complete(self, action_ex):
|
|
assert self.task_ex
|
|
|
|
# TODO(rakhmerov): Here we can define more informative messages
|
|
# cases when action is successful and when it's not. For example,
|
|
# in state_info we can specify the cause action.
|
|
# The use of action_ex.output.get('result') for state_info is not
|
|
# accurate because there could be action executions that had
|
|
# failed or was cancelled prior to this action execution.
|
|
state_info = {
|
|
states.SUCCESS: None,
|
|
states.ERROR: 'One or more action executions had failed.',
|
|
states.CANCELLED: 'One or more action executions was cancelled.'
|
|
}
|
|
|
|
with_items.increase_capacity(self.task_ex)
|
|
|
|
if with_items.is_completed(self.task_ex):
|
|
state = with_items.get_final_state(self.task_ex)
|
|
|
|
self.complete(state, state_info[state])
|
|
|
|
return
|
|
|
|
if (with_items.has_more_iterations(self.task_ex)
|
|
and with_items.get_concurrency(self.task_ex)):
|
|
self._schedule_actions()
|
|
|
|
def _schedule_actions(self):
|
|
input_dicts = self._get_with_items_input()
|
|
|
|
if not input_dicts:
|
|
self.complete(states.SUCCESS)
|
|
|
|
return
|
|
|
|
for idx, input_dict in input_dicts:
|
|
target = self._get_target(input_dict)
|
|
|
|
action = self._build_action()
|
|
|
|
action.validate_input(input_dict)
|
|
|
|
action.schedule(
|
|
input_dict,
|
|
target,
|
|
index=idx,
|
|
safe_rerun=self.task_spec.get_safe_rerun()
|
|
)
|
|
|
|
def _get_with_items_input(self):
|
|
"""Calculate input array for separating each action input.
|
|
|
|
Example:
|
|
DSL:
|
|
with_items:
|
|
- itemX in <% $.arrayI %>
|
|
- itemY in <% $.arrayJ %>
|
|
|
|
Assume arrayI = [1, 2], arrayJ = ['a', 'b'].
|
|
with_items_input = {
|
|
"itemX": [1, 2],
|
|
"itemY": ['a', 'b']
|
|
}
|
|
|
|
Then we get separated input:
|
|
inputs_per_item = [
|
|
{'itemX': 1, 'itemY': 'a'},
|
|
{'itemX': 2, 'itemY': 'b'}
|
|
]
|
|
|
|
:return: the list of tuples containing indexes
|
|
and the corresponding input dict.
|
|
"""
|
|
ctx_view = data_flow.ContextView(
|
|
self.ctx,
|
|
self.wf_ex.context,
|
|
self.wf_ex.input
|
|
)
|
|
|
|
with_items_inputs = expr.evaluate_recursively(
|
|
self.task_spec.get_with_items(),
|
|
ctx_view
|
|
)
|
|
|
|
with_items.validate_input(with_items_inputs)
|
|
|
|
inputs_per_item = []
|
|
|
|
for key, value in with_items_inputs.items():
|
|
for index, item in enumerate(value):
|
|
iter_context = {key: item}
|
|
|
|
if index >= len(inputs_per_item):
|
|
inputs_per_item.append(iter_context)
|
|
else:
|
|
inputs_per_item[index].update(iter_context)
|
|
|
|
action_inputs = []
|
|
|
|
for item_input in inputs_per_item:
|
|
new_ctx = utils.merge_dicts(item_input, self.ctx)
|
|
|
|
action_inputs.append(self._get_action_input(new_ctx))
|
|
|
|
with_items.prepare_runtime_context(
|
|
self.task_ex,
|
|
self.task_spec,
|
|
action_inputs
|
|
)
|
|
|
|
indices = with_items.get_indices_for_loop(self.task_ex)
|
|
|
|
with_items.decrease_capacity(self.task_ex, len(indices))
|
|
|
|
if indices:
|
|
current_inputs = operator.itemgetter(*indices)(action_inputs)
|
|
|
|
return zip(
|
|
indices,
|
|
current_inputs if isinstance(current_inputs, tuple)
|
|
else [current_inputs]
|
|
)
|
|
|
|
return []
|