Merge branch 'master' of ralfj.de:saartuer
[saartuer.git] / 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()