fastd-verify.py

#!/usr/bin/python3
'''
Created on Apr 29, 2021
@author: roland
'''

import os
import time
import argparse
import logging
import logging.handlers
import json

my_logger = logging.getLogger('fastd.verify')
my_logger.setLevel(logging.DEBUG)
log_handler = logging.handlers.SysLogHandler(address = '/dev/log')
my_logger.addHandler(log_handler)

DEFAULT_PREFERENCE = 50
MAX_DELAY = 8.0
OVERLOAD_DELAY = 9.0


def IsValidKey(FilePath, FastdKey):
    for FileName in os.listdir(FilePath):
        try:
            with open(os.path.join(FilePath, FileName), encoding = 'utf-8') as KeyFile:
                KeyData  = KeyFile.read()
        except:
            my_logger.error('fastd-verify: ** Error while reading KeyFile %s/%s' % (FilePath, FileName))
        else:
            if FastdKey in KeyData:
#                my_logger.debug('fastd-verify: FastdKey %s found in KeyFile %s/%s' % (FastdKey, FilePath, FileName))
                return True

    my_logger.debug('fastd-verify: ** Key %s not found in %s' % (FastdKey, FilePath))
    return False


def GetGwPreference(StatusFile, Segment):
    try:
        with open(StatusFile) as JsonFile:
            StatusDict = json.load(JsonFile)
            Preference = int(StatusDict['segments'][str(Segment)]['preference'])
    except:
        my_logger.error('fastd-verify: ** Error while checking GW StatusFile %s for Segment %d' % (StatusFile, Segment))
        Preference = DEFAULT_PREFERENCE

    return Preference


if __name__ == '__main__':
    parser = argparse.ArgumentParser(description='Verification of Fastd Connection Requests',
                                     formatter_class=argparse.RawDescriptionHelpFormatter)
    parser.add_argument('-k', '--keyfolder', dest='keyfolder', action='store', required=True, help='path to keyfiles')
    parser.add_argument('-g', '--gwstatus', dest='gwstatus', action='store', required=True, help='path to gwstatus.json')
    args = parser.parse_args()

    if 'INTERFACE' not in os.environ or 'PEER_KEY' not in os.environ:
        my_logger.error('fastd-verify: ** Error - Environment Variables not set')
    else:
        if IsValidKey(args.keyfolder, os.environ['PEER_KEY'].lower()):
            Preference = GetGwPreference(args.gwstatus, int(os.environ['INTERFACE'][3:]))
            my_logger.debug('fastd-verify: %s / %s / %d will be delayed...' % (os.environ['INTERFACE'], os.environ['PEER_KEY'], Preference))

            if Preference < 5:
                time.sleep(OVERLOAD_DELAY)
            elif Preference <= 10:
                time.sleep(MAX_DELAY)
            elif Preference <= 30:    # 10 .. 30
                time.sleep((1.00 - (Preference-10)/20.0 * 0.75) * MAX_DELAY)    # (10|8.0) .. (30|2.0)
            elif Preference <= 50:    # 30 .. 50
                time.sleep((0.25 - (Preference-30)/20.0 * 0.25) * MAX_DELAY)    # (30|2.0) .. (50|0.0)

            my_logger.debug('fastd-verify: %s / %s / %d ok.' % (os.environ['INTERFACE'], os.environ['PEER_KEY'], Preference))
            exit(0)
exit(1)