text: #!/usr/bin/env python
  #
  #    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.
  
  """Heat Engine Server.
  
  This does the work of actually implementing the API calls made by the user.
  Normal communications is done via the heat API which then calls into this
  engine.
  """
  
  import eventlet
  eventlet.monkey_patch()
  
  import sys
  
  from oslo_concurrency import processutils
  from oslo_config import cfg
  import oslo_i18n as i18n
  from oslo_log import log as logging
  from oslo_reports import guru_meditation_report as gmr
  from oslo_service import service
  
  from heat.common import config
  from heat.common import messaging
  from heat.common import profiler
  from heat.engine import template
  from heat.rpc import api as rpc_api
  from heat import version
  
  i18n.enable_lazy()
  
  LOG = logging.getLogger('heat.engine')
  
  
  def launch_engine(setup_logging=True):
      if setup_logging:
          logging.register_options(cfg.CONF)
      cfg.CONF(project='heat', prog='heat-engine',
               version=version.version_info.version_string())
      if setup_logging:
          logging.setup(cfg.CONF, 'heat-engine')
          logging.set_defaults()
      messaging.setup()
  
      config.startup_sanity_check()
  
      mgr = None
      try:
          mgr = template._get_template_extension_manager()
      except template.TemplatePluginNotRegistered as ex:
          LOG.critical("%s", ex)
      if not mgr or not mgr.names():
          sys.exit("ERROR: No template format plugins registered")
  
      from heat.engine import service as engine  # noqa
  
      profiler.setup('heat-engine', cfg.CONF.host)
      gmr.TextGuruMeditation.setup_autorun(version)
      srv = engine.EngineService(cfg.CONF.host, rpc_api.ENGINE_TOPIC)
      workers = cfg.CONF.num_engine_workers
      if not workers:
          workers = max(4, processutils.get_worker_count())
  
      launcher = service.launch(cfg.CONF, srv, workers=workers)
      if cfg.CONF.enable_cloud_watch_lite:
          # We create the periodic tasks here, which mean they are created
          # only in the parent process when num_engine_workers>1 is specified
          srv.create_periodic_tasks()
      return launcher
  
  
  def main():
      launcher = launch_engine()
      launcher.wait()
  