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         if not isinstance(type(receivers), list): receivers = [receivers]
  14         # construct content
  15         msg = email.mime.text.MIMEText(text.encode('UTF-8'), 'plain', 'UTF-8')
  16         msg['Subject'] = subject
  17         msg['Date'] = email.utils.formatdate(localtime=True)
  18         msg['From'] = sender
  19         msg['To'] = ', '.join(receivers)
  20         if replyTo is not None:
  21                 msg['Reply-To'] = replyTo
  22         # put into envelope and send
  23         s = smtplib.SMTP('localhost')
  24         s.sendmail(sender, receivers, msg.as_string())
  25         s.quit()
  26
  27 # logging function
  28 class Logger:
  29         def __init__ (self):
  30                 self.syslog = logging.getLogger("tuerd")
  31                 self.syslog.setLevel(logging.DEBUG)
  32                 self.syslog.addHandler(logging.handlers.SysLogHandler(address = '/dev/log',
  33                                                                                                                 facility = logging.handlers.SysLogHandler.LOG_LOCAL0))
  34
  35         def _log (self, lvl, what):
  36                 thestr = "%s[%d]: %s" % ("tuerd", os.getpid(), what)
  37                 # console log
  38                 if lvl >= printLevel:
  39                         print(thestr)
  40                 # syslog
  41                 if lvl >= syslogLevel:
  42                         self.syslog.log(lvl, thestr)
  43                 # mail log
  44                 if lvl >= mailLevel and mailAddress is not None:
  45                         sendeMail('Kritischer Türfehler', what, mailAddress)
  46
  47         def debug(self, what):
  48                 self._log(logging.DEBUG, what)
  49         def info(self, what):
  50                 self._log(logging.INFO, what)
  51         def warning(self, what):
  52                 self._log(logging.WARNING, what)
  53         def error(self, what):
  54                 self._log(logging.ERROR, what)
  55         def critical(self, what):
  56                 self._log(logging.CRITICAL, what)
  57
  58 logger = Logger()
  59
  60 # run a command asynchronously and log the return value if not 0
  61 # prefix must be a string identifying the code position where the call came from
  62 def fire_and_forget (cmd, log, prefix):
  63         def _fire_and_forget ():
  64                 with open("/dev/null", "w") as fnull:
  65                         retcode = subprocess.call(cmd, stdout=fnull, stderr=fnull)
  66                         if retcode is not 0:
  67                                 logger.error("%sReturn code %d at command: %s" % (prefix,retcode,str(cmd)))
  68         t = threading.Thread(target=_fire_and_forget)
  69         t.start()
  70
  71 # Threaded callback class
  72 class ThreadFunction():
  73         _CALL = 0
  74         _TERM = 1
  75
  76         def __init__(self, f, name):
  77                 self.name = name
  78                 self._f = f
  79                 self._q = queue.Queue()
  80                 self._t = threading.Thread(target=self._thread_func)
  81                 self._t.start()
  82
  83         def _thread_func(self):
  84                 while True:
  85                         (cmd, data) = self._q.get()
  86                         # run command
  87                         if cmd == ThreadFunction._CALL:
  88                                 try:
  89                                         self._f(*data)
  90                                 except Exception as e:
  91                                         logger.critical("ThreadFunction: Got exception out of handler thread %s: %s" % (self.name, str(e)))
  92                                         logger.debug(traceback.format_exc())
  93                         elif cmd == ThreadFunction._TERM:
  94                                 assert data is None
  95                                 break
  96                         else:
  97                                 logger.error("ThreadFunction: Command %d does not exist" % cmd)
  98
  99         def __call__(self, *arg):
 100                 self._q.put((ThreadFunction._CALL, arg))
 101
 102         def stop(self):
 103                 self._q.put((ThreadFunction._TERM, None))
 104                 self._t.join()
 105
 106 # Thread timer-repeater class: Call a function every <sleep_time> seconds
 107 class ThreadRepeater():
 108         def __init__(self, f, sleep_time, name):
 109                 self.name = name
 110                 self._f = f
 111                 self._stop = False
 112                 self._sleep_time = sleep_time
 113                 self._t = threading.Thread(target=self._thread_func)
 114                 self._t.start()
 115
 116         def _thread_func(self):
 117                 while True:
 118                         if self._stop:
 119                                 break
 120                         try:
 121                                 self._f()
 122                         except Exception as e:
 123                                 logger.critical("ThreadRepeater: Got exception out of handler thread %s: %s" % (self.name, str(e)))
 124                                 logger.debug(traceback.format_exc())
 125                         time.sleep(self._sleep_time)
 126
 127         def stop(self):
 128                 self._stop = True
 129                 self._t.join()