From: Scott Gasch Date: Fri, 4 Feb 2022 17:48:56 +0000 (-0800) Subject: Stop trying to cache mac addresses from house and cabin in the same X-Git-Url: https://wannabe.guru.org/gitweb/?a=commitdiff_plain;h=65e6f781dffb268be6ef0a015f4cc89b57b62a5e;p=python_utils.git Stop trying to cache mac addresses from house and cabin in the same file. --- diff --git a/arper.py b/arper.py index bdd97ac..3b308ca 100644 --- a/arper.py +++ b/arper.py @@ -28,10 +28,16 @@ cfg = config.add_commandline_args( ) cfg.add_argument( '--arper_cache_location', - default=f'{os.environ["HOME"]}/cache/.arp_table_cache', + default=site_config.get_config().arper_cache_file, metavar='FILENAME', help='Where to cache the kernel ARP table', ) +cfg.add_argument( + '--arper_supplimental_cache_location', + default=site_config.get_config(site_config.other_location()).arper_cache_file, + metavar='FILENAME', + help='Where someone else is caching the kernel ARP table', +) cfg.add_argument( '--arper_cache_max_staleness', type=argparse_utils.valid_duration, @@ -49,17 +55,27 @@ cfg.add_argument( @persistent.persistent_autoloaded_singleton() # type: ignore class Arper(persistent.Persistent): - def __init__(self, cached_state: Optional[BiDict] = None) -> None: + def __init__( + self, + cached_local_state: Optional[BiDict] = None, + cached_supplimental_state: Optional[BiDict] = None, + ) -> None: self.state = BiDict() - if cached_state is not None: - logger.debug('Loading Arper map from cached state.') - self.state = cached_state + if cached_local_state is not None: + logger.debug('Loading Arper map from cached local state.') + self.state = cached_local_state else: logger.debug('No usable cached state; calling /usr/sbin/arp') self.update_from_arp_scan() self.update_from_arp() if len(self.state) < config.config['arper_min_entries_to_be_valid']: raise Exception(f'Arper didn\'t find enough entries; only got {len(self.state)}.') + if cached_supplimental_state is not None: + logger.debug(f'Also added {len(cached_supplimental_state)} supplimental entries.') + for mac, ip in cached_supplimental_state.items(): + self.state[mac] = ip + for mac, ip in self.state.items(): + logger.debug(f'{mac} <-> {ip}') def update_from_arp_scan(self): network_spec = site_config.get_config().network @@ -101,15 +117,16 @@ class Arper(persistent.Persistent): return self.state.inverse.get(ip, None) @classmethod - @overrides - def load(cls) -> Any: - cache_file = config.config['arper_cache_location'] + def load_state(cls, cache_file: str, freshness_threshold_sec: int, state: BiDict): + if not file_utils.file_is_readable(cache_file): + logger.debug(f'Can\'t read {cache_file}') + return None if persistent.was_file_written_within_n_seconds( cache_file, - config.config['arper_cache_max_staleness'].total_seconds(), + freshness_threshold_sec, ): logger.debug(f'Loading state from {cache_file}') - cached_state = BiDict() + count = 0 with open(cache_file, 'r') as rf: contents = rf.readlines() for line in contents: @@ -119,15 +136,38 @@ class Arper(persistent.Persistent): mac = mac.strip() mac = mac.lower() ip = ip.strip() - cached_state[mac] = ip - if len(cached_state) > config.config['arper_min_entries_to_be_valid']: - return cls(cached_state) - else: - msg = f'{cache_file} is invalid: only {len(cached_state)} entries. Deleting it.' - logger.warning(msg) - warnings.warn(msg, stacklevel=2) + state[mac] = ip + count += 1 + else: + logger.debug(f'{cache_file} is too stale.') + + @classmethod + @overrides + def load(cls) -> Any: + local_state = BiDict() + cache_file = config.config['arper_cache_location'] + max_staleness = config.config['arper_cache_max_staleness'].total_seconds() + logger.debug(f'Trying to load main arper cache from {cache_file}...') + cls.load_state(cache_file, max_staleness, local_state) + if len(local_state) <= config.config['arper_min_entries_to_be_valid']: + msg = f'{cache_file} is invalid: only {len(local_state)} entries. Deleting it.' + logger.warning(msg) + warnings.warn(msg, stacklevel=2) + try: os.remove(cache_file) - logger.debug('No usable saved state found') + except Exception: + pass + + supplimental_state = BiDict() + cache_file = config.config['arper_supplimental_cache_location'] + max_staleness = config.config['arper_cache_max_staleness'].total_seconds() + logger.debug(f'Trying to suppliment arper state from {cache_file}...') + cls.load_state(cache_file, max_staleness, supplimental_state) + if len(supplimental_state) == 0: + supplimental_state = None + + if len(local_state) > 0: + return cls(local_state, supplimental_state) return None @overrides diff --git a/site_config.py b/site_config.py index 2335899..3bf049e 100644 --- a/site_config.py +++ b/site_config.py @@ -3,7 +3,7 @@ import logging import platform from dataclasses import dataclass -from typing import Callable +from typing import Callable, Optional # Note: this module is fairly early loaded. Be aware of dependencies. import config @@ -35,6 +35,7 @@ class SiteConfig(object): presence_location: Location is_anyone_present: Callable arper_minimum_device_count: int + arper_cache_file: str def get_location_name(): @@ -69,7 +70,29 @@ def is_anyone_present_wrapper(location: Location): return p.is_anyone_in_location_now(location) -def get_config(): +def other_location() -> str: + hostname = platform.node() + if '.house' in hostname: + location = 'CABIN' + elif '.cabin' in hostname: + location = 'HOUSE' + else: + raise Exception(f"{hostname} doesn't help me know where I'm running?!") + return location + + +def this_location() -> str: + hostname = platform.node() + if '.house' in hostname: + location = 'HOUSE' + elif '.cabin' in hostname: + location = 'CABIN' + else: + raise Exception(f"{hostname} doesn't help me know where I'm running?!") + return location + + +def get_config(location_override: Optional[str] = None): """ Get a configuration dataclass with information that is site-specific including the current running location. @@ -79,16 +102,17 @@ def get_config(): True """ - hostname = platform.node() - try: - location_override = config.config['site_config_override_location'] - except KeyError: - location_override = 'NONE' - if location_override == 'NONE': - if '.house' in hostname: - location = 'HOUSE' - elif '.cabin' in hostname: - location = 'CABIN' + if location_override is None: + try: + location_override = config.config['site_config_override_location'] + except KeyError: + location_override = None + + if location_override is None or location_override == 'NONE': + location = this_location() + else: + location = location_override + if location == 'HOUSE': return SiteConfig( location_name='HOUSE', @@ -99,6 +123,7 @@ def get_config(): presence_location=Location.HOUSE, is_anyone_present=lambda x=Location.HOUSE: is_anyone_present_wrapper(x), arper_minimum_device_count=50, + arper_cache_file='/home/scott/cache/.arp_table_cache_house', ) elif location == 'CABIN': return SiteConfig( @@ -110,6 +135,7 @@ def get_config(): presence_location=Location.CABIN, is_anyone_present=lambda x=Location.CABIN: is_anyone_present_wrapper(x), arper_minimum_device_count=15, + arper_cache_file='/home/scott/cache/.arp_table_cache_cabin', ) else: raise Exception(f'Unknown site location: {location}')