deb-mistral/mistral/engine1/commands.py
W Chan 318c097c5c Implement workflow execution environment - part 2
Modify engine start_workflow to take either a named environment
or adhoc environment (dict) in params. Save a copy of the
environment in start_params of the execution DB object. Subworkflows
will inherit environment from parent workflow. This is part 2 of a
series to implement execution environment.

Change-Id: I9af8dbf0f9ab98de81fff5612116203beae65c93
Implements: blueprint mistral-execution-environment
2015-01-14 07:50:16 -08:00

327 lines
10 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.
import abc
import copy
from oslo.config import cfg
import six
from mistral.db.v2 import api as db_api
from mistral.engine1 import policies
from mistral.engine1 import rpc
from mistral.engine1 import utils as e_utils
from mistral import expressions as expr
from mistral.openstack.common import log as logging
from mistral.services import action_manager as a_m
from mistral import utils
from mistral.workbook import parser as spec_parser
from mistral.workflow import data_flow
from mistral.workflow import states
from mistral.workflow import with_items
LOG = logging.getLogger(__name__)
WF_TRACE = logging.getLogger(cfg.CONF.workflow_trace_log_name)
@six.add_metaclass(abc.ABCMeta)
class EngineCommand(object):
"""Engine command interface."""
def run_local(self, exec_db, wf_handler, cause_task_db=None):
"""Runs local part of the command.
"Local" means that the code can be performed within a scope
of an opened DB transaction. For example, for all commands
that simply change a state of execution (e.g. depending on
some conditions) it's enough to implement only this method.
:param exec_db: Workflow execution DB object.
:param wf_handler: Workflow handler currently being used.
:param cause_task_db: Task that caused the command to run.
:return False if engine should stop further command processing,
True otherwise.
"""
return True
def run_remote(self, exec_db, wf_handler, cause_task_db=None):
"""Runs remote part of the command.
"Remote" means that the code cannot be performed within a scope
of an opened DB transaction. All commands that deal with remote
invocations should implement this method. However, they may also
need to implement "run_local" if they need to do something with
DB state of execution and/or tasks.
:param exec_db: Workflow execution DB object.
:param wf_handler: Workflow handler currently being used.
:param cause_task_db: Task that caused the command to run.
:return False if engine should stop further command processing,
True otherwise.
"""
return True
class Noop(EngineCommand):
"""No-op command."""
def run_local(self, exec_db, wf_handler, cause_task_db=None):
pass
def run_remote(self, exec_db, wf_handler, cause_task_db=None):
pass
class RunTask(EngineCommand):
def __init__(self, task_spec, task_db=None):
self.task_spec = task_spec
self.task_db = task_db
if task_db:
self.exec_db = task_db.execution
def run_local(self, exec_db, wf_handler, cause_task_db=None):
if self.task_db and self.task_db.state == states.IDLE:
LOG.debug('Resuming workflow task: %s' % self.task_spec)
self.task_db.state = states.RUNNING
return True
LOG.debug('Running workflow task: %s' % self.task_spec)
self._prepare_task(exec_db, wf_handler, cause_task_db)
self._before_task_start(wf_handler.wf_spec)
if exec_db.state == states.RUNNING:
return True
return False
def _prepare_task(self, exec_db, wf_handler, cause_task_db):
if self.task_db:
return
self.task_db = self._create_db_task(exec_db)
self.exec_db = self.task_db.execution
# Evaluate Data Flow properties ('input', 'in_context').
data_flow.prepare_db_task(
self.task_db,
self.task_spec,
wf_handler.get_upstream_tasks(self.task_spec),
exec_db,
cause_task_db
)
def _before_task_start(self, wf_spec):
for p in policies.build_policies(self.task_spec.get_policies(),
wf_spec):
p.before_task_start(self.task_db, self.task_spec)
def _create_db_task(self, exec_db):
return db_api.create_task({
'execution_id': exec_db.id,
'name': self.task_spec.get_name(),
'state': states.RUNNING,
'spec': self.task_spec.to_dict(),
'input': None,
'in_context': None,
'output': None,
'runtime_context': None,
'wf_name': exec_db.wf_name,
'project_id': exec_db.project_id
})
def run_remote(self, exec_db, wf_handler, cause_task_db=None):
self._run_task()
return True
def _run_task(self):
# Policies could possibly change task state.
if self.task_db.state != states.RUNNING:
return
task_name = self.task_db.name
if self.task_spec.get_action_name():
WF_TRACE.info("Task '%s' is RUNNING [action_name = %s]"
% (task_name, self.task_spec.get_action_name()))
self._run_action()
elif self.task_spec.get_workflow_name():
WF_TRACE.info("Task '%s' is RUNNING [workflow_name = %s]"
% (task_name, self.task_spec.get_workflow_name()))
self._run_workflow()
def _run_action(self):
exec_db = self.exec_db
wf_spec = spec_parser.get_workflow_spec(exec_db.wf_spec)
action_spec_name = self.task_spec.get_action_name()
action_db = e_utils.resolve_action(
exec_db.wf_name,
wf_spec.get_name(),
action_spec_name
)
action_input = self.task_db.input or {}
if action_db.spec:
# Ad-hoc action.
action_spec = spec_parser.get_action_spec(action_db.spec)
base_name = action_spec.get_base()
action_db = e_utils.resolve_action(
exec_db.wf_name,
wf_spec.get_name(),
base_name
)
base_input = action_spec.get_base_input()
if base_input:
action_input = expr.evaluate_recursively(
base_input,
action_input
)
else:
action_input = {}
target = expr.evaluate_recursively(
self.task_spec.get_target(),
utils.merge_dicts(
copy.copy(self.task_db.input),
copy.copy(self.task_db.in_context)
)
)
if a_m.has_action_context(
action_db.action_class, action_db.attributes or {}):
action_input.update(a_m.get_action_context(self.task_db))
with_items_spec = self.task_spec.get_with_items()
if with_items_spec:
action_input_collection = with_items.calc_input(action_input)
for a_input in action_input_collection:
rpc.get_executor_client().run_action(
self.task_db.id,
action_db.action_class,
action_db.attributes or {},
expr.evaluate_recursively(
self.task_spec.get_input(),
utils.merge_dicts(
copy.copy(a_input),
copy.copy(self.task_db.in_context)
)
),
target
)
else:
rpc.get_executor_client().run_action(
self.task_db.id,
action_db.action_class,
action_db.attributes or {},
action_input,
target
)
def _run_workflow(self):
parent_exec_db = self.exec_db
parent_wf_spec = spec_parser.get_workflow_spec(parent_exec_db.wf_spec)
wf_spec_name = self.task_spec.get_workflow_name()
wf_db = e_utils.resolve_workflow(
parent_exec_db.wf_name,
parent_wf_spec.get_name(),
wf_spec_name
)
wf_spec = spec_parser.get_workflow_spec(wf_db.spec)
wf_input = self.task_db.input
start_params = {'parent_task_id': self.task_db.id}
if 'environment' in parent_exec_db.start_params:
environment = parent_exec_db.start_params['environment']
start_params['environment'] = environment
for k, v in wf_input.items():
if k not in wf_spec.get_input():
start_params[k] = v
del wf_input[k]
rpc.get_engine_client().start_workflow(
wf_db.name,
wf_input,
**start_params
)
class FailWorkflow(EngineCommand):
def run_local(self, exec_db, wf_handler, cause_task_db=None):
wf_handler.fail_workflow()
return False
def run_remote(self, exec_db, wf_handler, cause_task_db=None):
return False
class SucceedWorkflow(EngineCommand):
def run_local(self, exec_db, wf_handler, cause_task_db=None):
wf_handler.succeed_workflow()
return False
def run_remote(self, exec_db, wf_handler, cause_task_db=None):
return False
class PauseWorkflow(EngineCommand):
def run_local(self, exec_db, wf_handler, cause_task_db=None):
wf_handler.pause_workflow()
return False
def run_remote(self, exec_db, wf_handler, cause_task_db=None):
return False
class RollbackWorkflow(EngineCommand):
def run_local(self, exec_db, wf_handler, cause_task_db=None):
return True
def run_remote(self, exec_db, wf_handler, cause_task_db=None):
return True
RESERVED_COMMANDS = {
'noop': Noop,
'fail': FailWorkflow,
'succeed': SucceedWorkflow,
'pause': PauseWorkflow,
'rollback': PauseWorkflow
}
def get_reserved_command(cmd_name):
return RESERVED_COMMANDS[cmd_name]() if cmd_name in RESERVED_COMMANDS \
else None