heron/shell/src/python/handlers/pidhandler.py

#!/usr/bin/env python3
# -*- encoding: utf-8 -*-

#  Licensed to the Apache Software Foundation (ASF) under one
#  or more contributor license agreements.  See the NOTICE file
#  distributed with this work for additional information
#  regarding copyright ownership.  The ASF licenses this file
#  to you 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.


''' pidhandler.py '''
import json
import tornado.web

from heron.shell.src.python import utils

class PidHandler(tornado.web.RequestHandler):
  """
  Responsible for getting the process ID for an instance.
  """

  # pylint: disable=attribute-defined-outside-init
  @tornado.web.asynchronous
  def get(self, instance_id):
    ''' get method '''
    self.content_type = 'application/json'
    self.write(json.dumps(utils.chain([['cat', "%s.pid" % instance_id]])).strip())
    self.finish()