"""A caching layer around the kernel's network mapping between IPs and MACs"""
+
import datetime
import logging
import os
-from typing import Any, Optional
import warnings
+from typing import Any, Optional
from overrides import overrides
import argparse_utils
-from collect.bidict import BiDict
import config
import exec_utils
import file_utils
import persistent
-import string_utils
import site_config
+import string_utils
+from collect.bidict import BiDict
logger = logging.getLogger(__name__)
type=argparse_utils.valid_duration,
default=datetime.timedelta(seconds=60 * 15),
metavar='DURATION',
- help='Max acceptable age of the kernel arp table cache'
+ help='Max acceptable age of the kernel arp table cache',
)
cfg.add_argument(
'--arper_min_entries_to_be_valid',
type=int,
default=site_config.get_config().arper_minimum_device_count,
- help='Min number of arp entries to bother persisting.'
+ help='Min number of arp entries to bother persisting.',
)
class Arper(persistent.Persistent):
- def __init__(
- self, cached_state: Optional[BiDict] = None
- ) -> None:
+ def __init__(self, cached_state: Optional[BiDict] = None) -> None:
self.state = BiDict()
if cached_state is not None:
logger.debug('Loading Arper map from cached state.')
self.update_from_arp_scan()
self.update_from_arp()
if len(self.state) < config.config['arper_min_entries_to_be_valid']:
- raise Exception('Arper didn\'t find enough entries; only got {len(self.state)}.')
+ raise Exception(
+ f'Arper didn\'t find enough entries; only got {len(self.state)}.'
+ )
def update_from_arp_scan(self):
network_spec = site_config.get_config().network
try:
output = exec_utils.cmd(
f'/usr/local/bin/arp-scan --retry=6 --timeout 350 --backoff=1.4 --random --numeric --plain --ignoredups {network_spec}',
- timeout_seconds=10.0
+ timeout_seconds=10.0,
)
except Exception as e:
logger.exception(e)
for line in output.split('\n'):
ip = string_utils.extract_ip_v4(line)
mac = string_utils.extract_mac_address(line)
- if ip is not None and mac is not None and mac != 'UNKNOWN' and ip != 'UNKNOWN':
+ if (
+ ip is not None
+ and mac is not None
+ and mac != 'UNKNOWN'
+ and ip != 'UNKNOWN'
+ ):
mac = mac.lower()
logger.debug(f'ARPER: {mac} => {ip}')
self.state[mac] = ip
def update_from_arp(self):
try:
- output = exec_utils.cmd(
- '/usr/sbin/arp -a',
- timeout_seconds=10.0
- )
+ output = exec_utils.cmd('/usr/sbin/arp -a', timeout_seconds=10.0)
except Exception as e:
logger.exception(e)
return
for line in output.split('\n'):
ip = string_utils.extract_ip_v4(line)
mac = string_utils.extract_mac_address(line)
- if ip is not None and mac is not None and mac != 'UNKNOWN' and ip != 'UNKNOWN':
+ if (
+ ip is not None
+ and mac is not None
+ and mac != 'UNKNOWN'
+ and ip != 'UNKNOWN'
+ ):
mac = mac.lower()
logger.debug(f'ARPER: {mac} => {ip}')
self.state[mac] = ip
def load(cls) -> Any:
cache_file = config.config['arper_cache_location']
if persistent.was_file_written_within_n_seconds(
- cache_file,
- config.config['arper_cache_max_staleness'].total_seconds(),
+ cache_file,
+ config.config['arper_cache_max_staleness'].total_seconds(),
):
logger.debug(f'Loading state from {cache_file}')
cached_state = BiDict()
return cls(cached_state)
else:
msg = f'{cache_file} is invalid: only {len(cached_state)} entries. Deleting it.'
- warnings.warn(msg)
logger.warning(msg)
+ warnings.warn(msg, stacklevel=2)
os.remove(cache_file)
logger.debug('No usable saved state found')
return None
@overrides
def save(self) -> bool:
if len(self.state) > config.config['arper_min_entries_to_be_valid']:
- logger.debug(
- f'Persisting state to {config.config["arper_cache_location"]}'
- )
+ logger.debug(f'Persisting state to {config.config["arper_cache_location"]}')
with file_utils.FileWriter(config.config['arper_cache_location']) as wf:
for (mac, ip) in self.state.items():
mac = mac.lower()