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'
   9
  10 # Mail logging handler
  11 def sendeMail(subject, text, receivers, sender='sphinx@hacksaar.de', replyTo=None):
  12         if not isinstance(type(receivers), list): receivers = [receivers]
  13         # construct content
  14         msg = email.mime.text.MIMEText(text.encode('UTF-8'), 'plain', 'UTF-8')
  15         msg['Subject'] = subject
  16         msg['Date'] = email.utils.formatdate(localtime=True)
  17         msg['From'] = sender
  18         msg['To'] = ', '.join(receivers)
  19         if replyTo is not None:
  20                 msg['Reply-To'] = replyTo
  21         # put into envelope and send
  22         s = smtplib.SMTP('ralfj.de')
  23         s.sendmail(sender, receivers, msg.as_string())
  24         s.quit()
  25
  26 # logging function
  27 class Logger:
  28         def __init__ (self):
  29                 self.syslog = logging.getLogger("tuerd")
  30                 self.syslog.setLevel(syslogLevel)
  31                 self.syslog.addHandler(logging.handlers.SysLogHandler(address = '/dev/log',
  32                                                                                                                 facility = logging.handlers.SysLogHandler.LOG_LOCAL0))
  33
  34         def _log (self, lvl, what):
  35                 thestr = "%s[%d]: %s" % ("osspd", os.getpid(), what)
  36                 # console log
  37                 print(thestr)
  38                 # syslog
  39                 self.syslog.log(lvl, thestr)
  40                 # mail log
  41                 if lvl >= mailLevel:
  42                         sendeMail('Kritischer Türfehler', what, mailAddress)
  43
  44         def debug(self, what):
  45                 self._log(logging.DEBUG, what)
  46         def info(self, what):
  47                 self._log(logging.INFO, what)
  48         def warning(self, what):
  49                 self._log(logging.WARNING, what)
  50         def error(self, what):
  51                 self._log(logging.ERROR, what)
  52         def critical(self, what):
  53                 self._log(logging.CRITICAL, what)
  54
  55 logger = Logger()
  56
  57 # run a command asynchronously and log the return value if not 0
  58 # prefix must be a string identifying the code position where the call came from
  59 def fire_and_forget (cmd, log, prefix):
  60         def _fire_and_forget ():
  61                 with open("/dev/null", "w") as fnull:
  62                         retcode = subprocess.call(cmd, stdout=fnull, stderr=fnull)
  63                         if retcode is not 0:
  64                                 logger.error("%sReturn code %d at command: %s" % (prefix,retcode,str(cmd)))
  65         t = threading.Thread(target=_fire_and_forget)
  66         t.start()
  67
  68 # Threaded callback class
  69 class ThreadFunction():
  70         _CALL = 0
  71         _TERM = 1
  72
  73         def __init__(self, f, name):
  74                 self.name = name
  75                 self._f = f
  76                 self._q = queue.Queue()
  77                 self._t = threading.Thread(target=self._thread_func)
  78                 self._t.start()
  79
  80         def _thread_func(self):
  81                 while True:
  82                         (cmd, data) = self._q.get()
  83                         # run command
  84                         if cmd == ThreadFunction._CALL:
  85                                 try:
  86                                         self._f(*data)
  87                                 except Exception as e:
  88                                         logger.critical("ThreadFunction: Got exception out of handler thread %s: %s" % (self.name, str(e)))
  89                                         logger.debug(traceback.format_exc())
  90                         elif cmd == ThreadFunction._TERM:
  91                                 assert data is None
  92                                 break
  93                         else:
  94                                 logger.error("ThreadFunction: Command %d does not exist" % cmd)
  95
  96         def __call__(self, *arg):
  97                 self._q.put((ThreadFunction._CALL, arg))
  98
  99         def stop(self):
 100                 self._q.put((ThreadFunction._TERM, None))
 101                 self._t.join()
 102
 103 # Thread timer-repeater class: Call a function every <sleep_time> seconds
 104 class ThreadRepeater():
 105         def __init__(self, f, sleep_time, name):
 106                 self.name = name
 107                 self._f = f
 108                 self._stop = False
 109                 self._sleep_time = sleep_time
 110                 self._t = threading.Thread(target=self._thread_func)
 111                 self._t.start()
 112
 113         def _thread_func(self):
 114                 while True:
 115                         if self._stop:
 116                                 break
 117                         try:
 118                                 self._f()
 119                         except Exception as e:
 120                                 logger.critical("ThreadRepeater: Got exception out of handler thread %s: %s" % (self.name, str(e)))
 121                                 logger.debug(traceback.format_exc())
 122                         time.sleep(self._sleep_time)
 123
 124         def stop(self):
 125                 self._stop = True
 126                 self._t.join()