azure/aria/aria-extension-cloudify/src/aria/aria/orchestrator/workflow_runner.py

   1 # Licensed to the Apache Software Foundation (ASF) under one or more
   2 # contributor license agreements.  See the NOTICE file distributed with
   3 # this work for additional information regarding copyright ownership.
   4 # The ASF licenses this file to You under the Apache License, Version 2.0
   5 # (the "License"); you may not use this file except in compliance with
   6 # the License.  You may obtain a copy of the License at
   7 #
   8 #     http://www.apache.org/licenses/LICENSE-2.0
   9 #
  10 # Unless required by applicable law or agreed to in writing, software
  11 # distributed under the License is distributed on an "AS IS" BASIS,
  12 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13 # See the License for the specific language governing permissions and
  14 # limitations under the License.
  15
  16 """
  17 Running workflows.
  18 """
  19
  20 import os
  21 import sys
  22 from datetime import datetime
  23
  24 from . import exceptions
  25 from .context.workflow import WorkflowContext
  26 from .workflows import builtin
  27 from .workflows.core import engine, graph_compiler
  28 from .workflows.executor.process import ProcessExecutor
  29 from ..modeling import models
  30 from ..modeling import utils as modeling_utils
  31 from ..utils.imports import import_fullname
  32
  33
  34 DEFAULT_TASK_MAX_ATTEMPTS = 30
  35 DEFAULT_TASK_RETRY_INTERVAL = 30
  36
  37
  38 class WorkflowRunner(object):
  39
  40     def __init__(self, model_storage, resource_storage, plugin_manager,
  41                  execution_id=None, retry_failed_tasks=False,
  42                  service_id=None, workflow_name=None, inputs=None, executor=None,
  43                  task_max_attempts=DEFAULT_TASK_MAX_ATTEMPTS,
  44                  task_retry_interval=DEFAULT_TASK_RETRY_INTERVAL):
  45         """
  46         Manages a single workflow execution on a given service.
  47
  48         :param workflow_name: workflow name
  49         :param service_id: service ID
  50         :param inputs: key-value dict of inputs for the execution
  51         :param model_storage: model storage API ("MAPI")
  52         :param resource_storage: resource storage API ("RAPI")
  53         :param plugin_manager: plugin manager
  54         :param executor: executor for tasks; defaults to a
  55          :class:`~aria.orchestrator.workflows.executor.process.ProcessExecutor` instance
  56         :param task_max_attempts: maximum attempts of repeating each failing task
  57         :param task_retry_interval: retry interval between retry attempts of a failing task
  58         """
  59
  60         if not (execution_id or (workflow_name and service_id)):
  61             exceptions.InvalidWorkflowRunnerParams(
  62                 "Either provide execution id in order to resume a workflow or workflow name "
  63                 "and service id with inputs")
  64
  65         self._is_resume = execution_id is not None
  66         self._retry_failed_tasks = retry_failed_tasks
  67
  68         self._model_storage = model_storage
  69         self._resource_storage = resource_storage
  70
  71         # the IDs are stored rather than the models themselves, so this module could be used
  72         # by several threads without raising errors on model objects shared between threads
  73
  74         if self._is_resume:
  75             self._execution_id = execution_id
  76             self._service_id = self.execution.service.id
  77             self._workflow_name = model_storage.execution.get(self._execution_id).workflow_name
  78         else:
  79             self._service_id = service_id
  80             self._workflow_name = workflow_name
  81             self._validate_workflow_exists_for_service()
  82             self._execution_id = self._create_execution_model(inputs).id
  83
  84         self._workflow_context = WorkflowContext(
  85             name=self.__class__.__name__,
  86             model_storage=self._model_storage,
  87             resource_storage=resource_storage,
  88             service_id=service_id,
  89             execution_id=self._execution_id,
  90             workflow_name=self._workflow_name,
  91             task_max_attempts=task_max_attempts,
  92             task_retry_interval=task_retry_interval)
  93
  94         # Set default executor and kwargs
  95         executor = executor or ProcessExecutor(plugin_manager=plugin_manager)
  96
  97         # transforming the execution inputs to dict, to pass them to the workflow function
  98         execution_inputs_dict = dict(inp.unwrapped for inp in self.execution.inputs.itervalues())
  99
 100         if not self._is_resume:
 101             workflow_fn = self._get_workflow_fn()
 102             self._tasks_graph = workflow_fn(ctx=self._workflow_context, **execution_inputs_dict)
 103             compiler = graph_compiler.GraphCompiler(self._workflow_context, executor.__class__)
 104             compiler.compile(self._tasks_graph)
 105
 106         self._engine = engine.Engine(executors={executor.__class__: executor})
 107
 108     @property
 109     def execution_id(self):
 110         return self._execution_id
 111
 112     @property
 113     def execution(self):
 114         return self._model_storage.execution.get(self.execution_id)
 115
 116     @property
 117     def service(self):
 118         return self._model_storage.service.get(self._service_id)
 119
 120     def execute(self):
 121         self._engine.execute(ctx=self._workflow_context,
 122                              resuming=self._is_resume,
 123                              retry_failed=self._retry_failed_tasks)
 124
 125     def cancel(self):
 126         self._engine.cancel_execution(ctx=self._workflow_context)
 127
 128     def _create_execution_model(self, inputs):
 129         execution = models.Execution(
 130             created_at=datetime.utcnow(),
 131             service=self.service,
 132             workflow_name=self._workflow_name,
 133             inputs={})
 134
 135         if self._workflow_name in builtin.BUILTIN_WORKFLOWS:
 136             workflow_inputs = dict()  # built-in workflows don't have any inputs
 137         else:
 138             workflow_inputs = self.service.workflows[self._workflow_name].inputs
 139
 140         # modeling_utils.validate_no_undeclared_inputs(declared_inputs=workflow_inputs,
 141         #                                              supplied_inputs=inputs or {})
 142         modeling_utils.validate_required_inputs_are_supplied(declared_inputs=workflow_inputs,
 143                                                              supplied_inputs=inputs or {})
 144         execution.inputs = modeling_utils.merge_parameter_values(
 145             inputs, workflow_inputs, model_cls=models.Input)
 146         # TODO: these two following calls should execute atomically
 147         self._validate_no_active_executions(execution)
 148         self._model_storage.execution.put(execution)
 149         return execution
 150
 151     def _validate_workflow_exists_for_service(self):
 152         if self._workflow_name not in self.service.workflows and \
 153                         self._workflow_name not in builtin.BUILTIN_WORKFLOWS:
 154             raise exceptions.UndeclaredWorkflowError(
 155                 'No workflow policy {0} declared in service {1}'
 156                 .format(self._workflow_name, self.service.name))
 157
 158     def _validate_no_active_executions(self, execution):
 159         active_executions = [e for e in self.service.executions if e.is_active()]
 160         if active_executions:
 161             raise exceptions.ActiveExecutionsError(
 162                 "Can't start execution; Service {0} has an active execution with ID {1}"
 163                 .format(self.service.name, active_executions[0].id))
 164
 165     def _get_workflow_fn(self):
 166         if self._workflow_name in builtin.BUILTIN_WORKFLOWS:
 167             return import_fullname('{0}.{1}'.format(builtin.BUILTIN_WORKFLOWS_PATH_PREFIX,
 168                                                     self._workflow_name))
 169
 170         workflow = self.service.workflows[self._workflow_name]
 171
 172         # TODO: Custom workflow support needs improvement, currently this code uses internal
 173         # knowledge of the resource storage; Instead, workflows should probably be loaded
 174         # in a similar manner to operation plugins. Also consider passing to import_fullname
 175         # as paths instead of appending to sys path.
 176         service_template_resources_path = os.path.join(
 177             self._resource_storage.service_template.base_path,
 178             str(self.service.service_template.id))
 179         sys.path.append(service_template_resources_path)
 180
 181         try:
 182             workflow_fn = import_fullname(workflow.function)
 183         except ImportError:
 184             raise exceptions.WorkflowImplementationNotFoundError(
 185                 'Could not find workflow {0} function at {1}'.format(
 186                     self._workflow_name, workflow.function))
 187
 188         return workflow_fn