src/ztdnslib.py

   1 import yaml
   2 import psycopg2
   3 import os
   4 import fcntl
   5
   6 db_config_path = '/etc/0tdns/db_connection_config.yml'
   7 logfile = '/var/log/0tdns.log'
   8
   9 def get_ztdns_config():
  10     return yaml.safe_load(open(db_config_path, 'r'))
  11
  12 def start_db_connection(config):
  13     connection = psycopg2.connect(user=config['user'], password=config['password'],
  14                                   host=config['host'], port=config['port'],
  15                                   database=config['database'])
  16     # we might later decide that each user of start_db_connection()
  17     # should set it themselves - but for now, set it here
  18     connection.autocommit = True
  19     return connection
  20
  21 # we'll use it for setting SNAT
  22 # https://stackoverflow.com/questions/166506/finding-local-ip-addresses-using-pythons-stdlib
  23 def get_default_host_address(remote_address):
  24     import socket
  25     s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
  26     s.connect((remote_address, 80))
  27     hostaddr = s.getsockname()[0]
  28     s.close()
  29     return hostaddr
  30
  31 def log(msg):
  32     msg = bytearray(msg + '\n', "UTF-8")
  33     fd = os.open(logfile, os.O_APPEND | os.O_WRONLY | os.O_CREAT)
  34     try:
  35         fcntl.flock(fd, fcntl.LOCK_EX)
  36         os.write(fd, msg)
  37         fcntl.flock(fd, fcntl.LOCK_UN)
  38     finally:
  39         os.close(fd)