check_port_listening.py 1.67 KB
from zope.interface import implementer
from slapos.grid.promise import interface
from slapos.grid.promise.generic import GenericPromise

import socket
import sys

@implementer(interface.IPromise)
class RunPromise(GenericPromise):
  def __init__(self, config):
    super(RunPromise, self).__init__(config)
    # check port is listening at least every 2 minutes
    self.setPeriodicity(minute=2)

  def sense(self):
    """
      Simply test if we can connect to specified host:port.
    """
    hostname = self.getConfig('hostname')
    # if type of port should be int or str, unicode is not accepted.
    port = int(self.getConfig('port'))

    addr = (hostname , port)
    # in case of any error, we call "logger.error"
    # note that we could simply let the function raise an error, it would have the same effect
    # in this case the following code would be enough:
    #    socket.create_connection(addr).close()
    #    self.logger.info("port connection OK")
    try:
      socket.create_connection(addr).close()
    except (socket.herror, socket.gaierror) as e:
      self.logger.error("ERROR hostname/port ({}) is not correct: {}".format(addr, e))
    except (socket.error, socket.timeout) as e:
      self.logger.error("ERROR while connecting to {}: {}".format(addr, e))
    else:
      self.logger.info("port connection OK ({})".format(addr))

  # no need to define Test as it is the default implementation
  #def test(self):
  #  """
  #    Test is failing if last sense was bad.
  #  """
  #  return self._test(result_count=1, failure_amount=1)

  def anomaly(self):
    """
      There is an anomaly if last 3 senses were bad.
    """
    return self._anomaly(result_count=3, failure_amount=3)