# This file is part of cloud-init. See LICENSE file for license information. """Handle reconfiguration on hotplug events""" import abc import argparse import os import sys import time from cloudinit import log from cloudinit import reporting from cloudinit import stages from cloudinit.event import EventScope, EventType from cloudinit.net import activators, read_sys_net_safe from cloudinit.net.network_state import parse_net_config_data from cloudinit.reporting import events from cloudinit.stages import Init from cloudinit.sources import DataSource # noqa: F401 from cloudinit.sources import DataSourceNotFoundException LOG = log.getLogger(__name__) NAME = 'hotplug-hook' def get_parser(parser=None): """Build or extend an arg parser for hotplug-hook utility. @param parser: Optional existing ArgumentParser instance representing the subcommand which will be extended to support the args of this utility. @returns: ArgumentParser with proper argument configuration. """ if not parser: parser = argparse.ArgumentParser(prog=NAME, description=__doc__) parser.description = __doc__ parser.add_argument( "-s", "--subsystem", required=True, help="subsystem to act on", choices=['net'] ) subparsers = parser.add_subparsers( title='Hotplug Action', dest='hotplug_action' ) subparsers.required = True subparsers.add_parser( 'query', help='query if hotplug is enabled for given subsystem' ) parser_handle = subparsers.add_parser( 'handle', help='handle the hotplug event') parser_handle.add_argument( "-d", "--devpath", required=True, metavar="PATH", help="sysfs path to hotplugged device" ) parser_handle.add_argument( "-u", "--udevaction", required=True, help="action to take", choices=['add', 'remove'] ) return parser class UeventHandler(abc.ABC): def __init__(self, id, datasource, devpath, action, success_fn): self.id = id self.datasource = datasource # type: DataSource self.devpath = devpath self.action = action self.success_fn = success_fn @abc.abstractmethod def apply(self): raise NotImplementedError() @property @abc.abstractmethod def config(self): raise NotImplementedError() @abc.abstractmethod def device_detected(self) -> bool: raise NotImplementedError() def detect_hotplugged_device(self): detect_presence = None if self.action == 'add': detect_presence = True elif self.action == 'remove': detect_presence = False else: raise ValueError('Unknown action: %s' % self.action) if detect_presence != self.device_detected(): raise RuntimeError( 'Failed to detect %s in updated metadata' % self.id) def success(self): return self.success_fn() def update_metadata(self): result = self.datasource.update_metadata_if_supported([ EventType.HOTPLUG]) if not result: raise RuntimeError( 'Datasource %s not updated for ' 'event %s' % (self.datasource, EventType.HOTPLUG) ) return result class NetHandler(UeventHandler): def __init__(self, datasource, devpath, action, success_fn): # convert devpath to mac address id = read_sys_net_safe(os.path.basename(devpath), 'address') super().__init__(id, datasource, devpath, action, success_fn) def apply(self): self.datasource.distro.apply_network_config( self.config, bring_up=False, ) interface_name = os.path.basename(self.devpath) activator = activators.select_activator() if self.action == 'add': if not activator.bring_up_interface(interface_name): raise RuntimeError( 'Failed to bring up device: {}'.format(self.devpath)) elif self.action == 'remove': if not activator.bring_down_interface(interface_name): raise RuntimeError( 'Failed to bring down device: {}'.format(self.devpath)) @property def config(self): return self.datasource.network_config def device_detected(self) -> bool: netstate = parse_net_config_data(self.config) found = [ iface for iface in netstate.iter_interfaces() if iface.get('mac_address') == self.id ] LOG.debug('Ifaces with ID=%s : %s', self.id, found) return len(found) > 0 SUBSYSTEM_PROPERTES_MAP = { 'net': (NetHandler, EventScope.NETWORK), } def is_enabled(hotplug_init, subsystem): try: scope = SUBSYSTEM_PROPERTES_MAP[subsystem][1] except KeyError as e: raise Exception( 'hotplug-hook: cannot handle events for subsystem: {}'.format( subsystem) ) from e return stages.update_event_enabled( datasource=hotplug_init.datasource, cfg=hotplug_init.cfg, event_source_type=EventType.HOTPLUG, scope=scope ) def initialize_datasource(hotplug_init, subsystem): LOG.debug('Fetching datasource') datasource = hotplug_init.fetch(existing="trust") if not datasource.get_supported_events([EventType.HOTPLUG]): LOG.debug('hotplug not supported for event of type %s', subsystem) return if not is_enabled(hotplug_init, subsystem): LOG.debug('hotplug not enabled for event of type %s', subsystem) return return datasource def handle_hotplug( hotplug_init: Init, devpath, subsystem, udevaction ): datasource = initialize_datasource(hotplug_init, subsystem) if not datasource: return handler_cls = SUBSYSTEM_PROPERTES_MAP[subsystem][0] LOG.debug('Creating %s event handler', subsystem) event_handler = handler_cls( datasource=datasource, devpath=devpath, action=udevaction, success_fn=hotplug_init._write_to_cache ) # type: UeventHandler wait_times = [1, 3, 5, 10, 30] for attempt, wait in enumerate(wait_times): LOG.debug( 'subsystem=%s update attempt %s/%s', subsystem, attempt, len(wait_times) ) try: LOG.debug('Refreshing metadata') event_handler.update_metadata() LOG.debug('Detecting device in updated metadata') event_handler.detect_hotplugged_device() LOG.debug('Applying config change') event_handler.apply() LOG.debug('Updating cache') event_handler.success() break except Exception as e: LOG.debug('Exception while processing hotplug event. %s', e) time.sleep(wait) last_exception = e else: raise last_exception # type: ignore def handle_args(name, args): # Note that if an exception happens between now and when logging is # setup, we'll only see it in the journal hotplug_reporter = events.ReportEventStack( name, __doc__, reporting_enabled=True ) hotplug_init = Init(ds_deps=[], reporter=hotplug_reporter) hotplug_init.read_cfg() log.setupLogging(hotplug_init.cfg) if 'reporting' in hotplug_init.cfg: reporting.update_configuration(hotplug_init.cfg.get('reporting')) # Logging isn't going to be setup until now LOG.debug( '%s called with the following arguments: {' 'hotplug_action: %s, subsystem: %s, udevaction: %s, devpath: %s}', name, args.hotplug_action, args.subsystem, args.udevaction if 'udevaction' in args else None, args.devpath if 'devpath' in args else None, ) with hotplug_reporter: try: if args.hotplug_action == 'query': try: datasource = initialize_datasource( hotplug_init, args.subsystem) except DataSourceNotFoundException: print( "Unable to determine hotplug state. No datasource " "detected") sys.exit(1) print('enabled' if datasource else 'disabled') else: handle_hotplug( hotplug_init=hotplug_init, devpath=args.devpath, subsystem=args.subsystem, udevaction=args.udevaction, ) except Exception: LOG.exception('Received fatal exception handling hotplug!') raise LOG.debug('Exiting hotplug handler') reporting.flush_events() if __name__ == '__main__': args = get_parser().parse_args() handle_args(NAME, args)