#!/usr/bin/python
# Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
import atexit
import errno
import logging
import re
import sys
import socket
import threading
import xmlrpclib
import rpm_controller
import rpm_logging_config
from config import rpm_config
from MultiThreadedXMLRPCServer import MultiThreadedXMLRPCServer
from rpm_infrastructure_exception import RPMInfrastructureException
import common
from autotest_lib.site_utils.rpm_control_system import utils
LOG_FILENAME_FORMAT = rpm_config.get('GENERAL','dispatcher_logname_format')
class RPMDispatcher(object):
"""
This class is the RPM dispatcher server and it is responsible for
communicating directly to the RPM devices to change a DUT's outlet status.
When an RPMDispatcher is initialized it registers itself with the frontend
server, who will field out outlet requests to this dispatcher.
Once a request is received the dispatcher looks up the RPMController
instance for the given DUT and then queues up the request and blocks until
it is processed.
@var _address: IP address or Hostname of this dispatcher server.
@var _frontend_server: URI of the frontend server.
@var _lock: Lock used to synchronize access to _worker_dict.
@var _port: Port assigned to this server instance.
@var _worker_dict: Dictionary mapping RPM hostname's to RPMController
instances.
"""
def __init__(self, address, port):
"""
RPMDispatcher constructor.
Initialized instance vars and registers this server with the frontend
server.
@param address: Address of this dispatcher server.
@param port: Port assigned to this dispatcher server.
@raise RPMInfrastructureException: Raised if the dispatch server is
unable to register with the frontend
server.
"""
self._address = address
self._port = port
self._lock = threading.Lock()
self._worker_dict = {}
self._frontend_server = rpm_config.get('RPM_INFRASTRUCTURE',
'frontend_uri')
logging.info('Registering this rpm dispatcher with the frontend '
'server at %s.', self._frontend_server)
client = xmlrpclib.ServerProxy(self._frontend_server)
# De-register with the frontend when the dispatcher exit's.
atexit.register(self._unregister)
try:
client.register_dispatcher(self._get_serveruri())
except socket.error as er:
err_msg = ('Unable to register with frontend server. Error: %s.' %
errno.errorcode[er.errno])
logging.error(err_msg)
raise RPMInfrastructureException(err_msg)
def _worker_dict_put(self, key, value):
"""
Private method used to synchronize access to _worker_dict.
@param key: key value we are using to access _worker_dict.
@param value: value we are putting into _worker_dict.
"""
with self._lock:
self._worker_dict[key] = value
def _worker_dict_get(self, key):
"""
Private method used to synchronize access to _worker_dict.
@param key: key value we are using to access _worker_dict.
@return: value found when accessing _worker_dict
"""
with self._lock:
return self._worker_dict.get(key)
def is_up(self):
"""
Allows the frontend server to see if the dispatcher server is up before
attempting to queue requests.
@return: True. If connection fails, the client proxy will throw a socket
error on the client side.
"""
return True
def queue_request(self, powerunit_info_dict, new_state):
"""
Looks up the appropriate RPMController instance for the device and queues
up the request.
@param powerunit_info_dict: A dictionary, containing the attribute/values
of an unmarshalled PowerUnitInfo instance.
@param new_state: [ON, OFF, CYCLE] state we want to the change the
outlet to.
@return: True if the attempt to change power state was successful,
False otherwise.
"""
powerunit_info = utils.PowerUnitInfo(**powerunit_info_dict)
logging.info('Received request to set device: %s to state: %s',
powerunit_info.device_hostname, new_state)
rpm_controller = self._get_rpm_controller(
powerunit_info.powerunit_hostname,
powerunit_info.hydra_hostname)
return rpm_controller.queue_request(powerunit_info, new_state)
def _get_rpm_controller(self, rpm_hostname, hydra_hostname=None):
"""
Private method that retreives the appropriate RPMController instance
for this RPM Hostname or calls _create_rpm_controller it if it does not
already exist.
@param rpm_hostname: hostname of the RPM whose RPMController we want.
@return: RPMController instance responsible for this RPM.
"""
if not rpm_hostname:
return None
rpm_controller = self._worker_dict_get(rpm_hostname)
if not rpm_controller:
rpm_controller = self._create_rpm_controller(
rpm_hostname, hydra_hostname)
self._worker_dict_put(rpm_hostname, rpm_controller)
return rpm_controller
def _create_rpm_controller(self, rpm_hostname, hydra_hostname):
"""
Determines the type of RPMController required and initializes it.
@param rpm_hostname: Hostname of the RPM we need to communicate with.
@return: RPMController instance responsible for this RPM.
"""
hostname_elements = rpm_hostname.split('-')
if hostname_elements[-2] == 'poe':
# POE switch hostname looks like 'chromeos2-poe-switch1'.
logging.info('The controller is a Cisco POE switch.')
return rpm_controller.CiscoPOEController(rpm_hostname)
else:
# The device is an RPM.
rack_id = hostname_elements[-2]
rpm_typechecker = re.compile('rack[0-9]+[a-z]+')
if rpm_typechecker.match(rack_id):
logging.info('RPM is a webpowered device.')
return rpm_controller.WebPoweredRPMController(rpm_hostname)
else:
logging.info('RPM is a Sentry CDU device.')
return rpm_controller.SentryRPMController(
hostname=rpm_hostname,
hydra_hostname=hydra_hostname)
def _get_serveruri(self):
"""
Formats the _address and _port into a meaningful URI string.
@return: URI of this dispatch server.
"""
return 'http://%s:%d' % (self._address, self._port)
def _unregister(self):
"""
Tells the frontend server that this dispatch server is shutting down and
to unregister it.
Called by atexit.
@raise RPMInfrastructureException: Raised if the dispatch server is
unable to unregister with the
frontend server.
"""
logging.info('Dispatch server shutting down. Unregistering with RPM '
'frontend server.')
client = xmlrpclib.ServerProxy(self._frontend_server)
try:
client.unregister_dispatcher(self._get_serveruri())
except socket.error as er:
err_msg = ('Unable to unregister with frontend server. Error: %s.' %
errno.errorcode[er.errno])
logging.error(err_msg)
raise RPMInfrastructureException(err_msg)
def launch_server_on_unused_port():
"""
Looks up an unused port on this host and launches the xmlrpc server.
Useful for testing by running multiple dispatch servers on the same host.
@return: server,port - server object and the port that which it is listening
to.
"""
address = socket.gethostbyname(socket.gethostname())
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# Set this socket to allow reuse.
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
sock.bind(('', 0))
port = sock.getsockname()[1]
server = MultiThreadedXMLRPCServer((address, port),
allow_none=True)
sock.close()
return server, port
if __name__ == '__main__':
"""
Main function used to launch the dispatch server. Creates an instance of
RPMDispatcher and registers it to a MultiThreadedXMLRPCServer instance.
"""
if len(sys.argv) > 1:
print 'Usage: ./%s, no arguments available.' % sys.argv[0]
sys.exit(1)
rpm_logging_config.start_log_server(LOG_FILENAME_FORMAT)
rpm_logging_config.set_up_logging(use_log_server=True)
# Get the local ip _address and set the server to utilize it.
address = socket.gethostbyname(socket.gethostname())
server, port = launch_server_on_unused_port()
rpm_dispatcher = RPMDispatcher(address, port)
server.register_instance(rpm_dispatcher)
server.serve_forever()