libtuer.py

   1 import logging, logging.handlers, os, time, queue, threading, subprocess
   2 import traceback, smtplib
   3 import email.mime.text, email.utils
   4
   5 # Logging configuration
   6 syslogLevel = logging.INFO
   7 mailLevel   = logging.CRITICAL # must be "larger" than syslog level!
   8 mailAddress = ['post+tuer'+'@'+'ralfj.de', 'vorstand@lists.hacksaar.de']
   9 printLevel  = logging.DEBUG
  10
  11 # Mail logging handler
  12 def sendeMail(subject, text, receivers, sender='sphinx@hacksaar.de', replyTo=None):
  13         assert isinstance(receivers, list)
  14         if not len(receivers): return # nothing to do
  15         # construct content
  16         msg = email.mime.text.MIMEText(text.encode('UTF-8'), 'plain', 'UTF-8')
  17         msg['Subject'] = subject
  18         msg['Date'] = email.utils.formatdate(localtime=True)
  19         msg['From'] = sender
  20         msg['To'] = ', '.join(receivers)
  21         if replyTo is not None:
  22                 msg['Reply-To'] = replyTo
  23         # put into envelope and send
  24         s = smtplib.SMTP('localhost')
  25         s.sendmail(sender, receivers, msg.as_string())
  26         s.quit()
  27
  28 # logging function
  29 class Logger:
  30         def __init__ (self):
  31                 self.syslog = logging.getLogger("tuerd")
  32                 self.syslog.setLevel(logging.DEBUG)
  33                 self.syslog.addHandler(logging.handlers.SysLogHandler(address = '/dev/log',
  34                                                                                                                 facility = logging.handlers.SysLogHandler.LOG_LOCAL0))
  35
  36         def _log (self, lvl, what):
  37                 thestr = "%s[%d]: %s" % ("tuerd", os.getpid(), what)
  38                 # console log
  39                 if lvl >= printLevel:
  40                         print(thestr)
  41                 # syslog
  42                 if lvl >= syslogLevel:
  43                         self.syslog.log(lvl, thestr)
  44                 # mail log
  45                 if lvl >= mailLevel and mailAddress is not None:
  46                         sendeMail('Kritischer Türfehler', what, mailAddress)
  47
  48         def debug(self, what):
  49                 self._log(logging.DEBUG, what)
  50         def info(self, what):
  51                 self._log(logging.INFO, what)
  52         def warning(self, what):
  53                 self._log(logging.WARNING, what)
  54         def error(self, what):
  55                 self._log(logging.ERROR, what)
  56         def critical(self, what):
  57                 self._log(logging.CRITICAL, what)
  58
  59 logger = Logger()
  60
  61 # run a command asynchronously and log the return value if not 0
  62 # prefix must be a string identifying the code position where the call came from
  63 def fire_and_forget (cmd, log, prefix):
  64         def _fire_and_forget ():
  65                 with open("/dev/null", "w") as fnull:
  66                         retcode = subprocess.call(cmd, stdout=fnull, stderr=fnull)
  67                         if retcode is not 0:
  68                                 logger.error("%sReturn code %d at command: %s" % (prefix,retcode,str(cmd)))
  69         t = threading.Thread(target=_fire_and_forget)
  70         t.start()
  71
  72 # Threaded callback class
  73 class ThreadFunction():
  74         _CALL = 0
  75         _TERM = 1
  76
  77         def __init__(self, f, name):
  78                 self.name = name
  79                 self._f = f
  80                 self._q = queue.Queue()
  81                 self._t = threading.Thread(target=self._thread_func)
  82                 self._t.start()
  83
  84         def _thread_func(self):
  85                 while True:
  86                         (cmd, data) = self._q.get()
  87                         # run command
  88                         if cmd == ThreadFunction._CALL:
  89                                 try:
  90                                         self._f(*data)
  91                                 except Exception as e:
  92                                         logger.critical("ThreadFunction: Got exception out of handler thread %s: %s" % (self.name, str(e)))
  93                                         logger.debug(traceback.format_exc())
  94                         elif cmd == ThreadFunction._TERM:
  95                                 assert data is None
  96                                 break
  97                         else:
  98                                 logger.error("ThreadFunction: Command %d does not exist" % cmd)
  99
 100         def __call__(self, *arg):
 101                 self._q.put((ThreadFunction._CALL, arg))
 102
 103         def stop(self):
 104                 self._q.put((ThreadFunction._TERM, None))
 105                 self._t.join()
 106
 107 # Thread timer-repeater class: Call a function every <sleep_time> seconds
 108 class ThreadRepeater():
 109         def __init__(self, f, sleep_time, name):
 110                 self.name = name
 111                 self._f = f
 112                 self._stop = False
 113                 self._sleep_time = sleep_time
 114                 self._t = threading.Thread(target=self._thread_func)
 115                 self._t.start()
 116
 117         def _thread_func(self):
 118                 while True:
 119                         if self._stop:
 120                                 break
 121                         try:
 122                                 self._f()
 123                         except Exception as e:
 124                                 logger.critical("ThreadRepeater: Got exception out of handler thread %s: %s" % (self.name, str(e)))
 125                                 logger.debug(traceback.format_exc())
 126                         time.sleep(self._sleep_time)
 127
 128         def stop(self):
 129                 self._stop = True
 130                 self._t.join()