codemux.py

   1 # $Id$
   2 # $URL$
   3
   4 """Codemux configurator.  Monitors slice attributes and configures CoDemux to mux port 80 based on HOST field in HTTP request.  Forwards to localhost port belonging to configured slice."""
   5
   6 import logger
   7 import os
   8 import vserver
   9 from sets import Set
  10
  11 CODEMUXCONF="/etc/codemux/codemux.conf"
  12
  13 def start(options, config):
  14     pass
  15
  16
  17 def GetSlivers(data):
  18     """For each sliver with the codemux attribute, parse out "host,port" and make entry in conf.  Restart service after."""
  19     logger.log("codemux:  Starting.", 2)
  20     # slices already in conf
  21     slicesinconf = parseConf()
  22     # slices that need to be written to the conf
  23     codemuxslices = {}
  24     _writeconf = False
  25     # Parse attributes and update dict of scripts
  26     for sliver in data['slivers']:
  27         for attribute in sliver['attributes']:
  28             if attribute['name'] == 'codemux':
  29                 # add to conf.  Attribute is [host, port]
  30                 [host, port] = attribute['value'].split(",")
  31                 try:
  32                     # Check to see if sliver is running.  If not, continue
  33                     if vserver.VServer(sliver['name']).is_running():
  34                         # Add to dict of codemuxslices
  35                         codemuxslices[sliver['name']] = {'host': host, 'port': port}
  36                         # Check if new
  37                         if sliver['name'] not in slicesinconf.keys():
  38                             logger.log("codemux:  New slice %s using %s" % \
  39                                 (sliver['name'], host))
  40                             #  Toggle write.
  41                             _writeconf = True
  42                         # Check old slivers for changes
  43                         else:
  44                             # Get info about slice in conf
  45                             sliverinconf = slicesinconf[sliver['name']]
  46                             # Check values for changes.
  47                             if (sliverinconf['host'] != host) or \
  48                                 (sliverinconf['port'] != port):
  49                                 logger.log("codemux:  Updating slice %s" % sliver['name'])
  50                                 # use updated values
  51                                 codemuxslices[sliver['name']] = {'host': host, 'port': port}
  52                                 #  Toggle write.
  53                                 _writeconf = True
  54                 except:
  55                     logger.log("codemux:  sliver %s not running yet.  Deferring."\
  56                                 % sliver['name'])
  57
  58                     logger.log_exc(name = "codemux")
  59                     pass
  60
  61     # Remove slices from conf that no longer have the attribute
  62     for deadslice in Set(slicesinconf.keys()) - Set(codemuxslices.keys()):
  63         logger.log("codemux:  Removing %s" % deadslice)
  64         _writeconf = True
  65
  66     if _writeconf:  writeConf(codemuxslices)
  67
  68 def writeConf(slivers, conf = CODEMUXCONF):
  69     '''Write conf with default entry up top. Restart service.'''
  70     f = open(conf, "w")
  71     f.write("* root 1080\n")
  72     for (slice, params) in slivers.iteritems():
  73         f.write("%s %s %s\n" % (params['host'], slice, params['port']))
  74     f.truncate()
  75     f.close()
  76     try:  restartService()
  77     except:  logger.log_exc()
  78
  79 def parseConf(conf = CODEMUXCONF):
  80     '''Parse the CODEMUXCONF and return dict of slices in conf. {slice: (host,port)}'''
  81     slicesinconf = {}
  82     try:
  83         f = open(conf)
  84         for line in f.readlines():
  85             if line.startswith("#") or (len(line.split()) != 3)\
  86             or line.startswith("*"):
  87                 continue
  88             (host, slice, port) = line.split()[:3]
  89             logger.log("codemux:  found %s in conf" % slice, 2)
  90             slicesinconf[slice] = {"host": host, "port": port}
  91         f.close()
  92     except: logger.log_exc()
  93     return slicesinconf
  94
  95 def restartService():
  96     logger.log("codemux:  Restarting codemux service")
  97     os.system("/etc/init.d/codemux stop")
  98     f = os.popen("/sbin/pidof codemux")
  99     tmp = f.readlines()
 100     f.close()
 101     if len(tmp) > 0:
 102         pids = tmp[0].rstrip("\n").split()
 103         for pid in pids:
 104             logger.log("codemux:  Killing stalled pid %s" % pid, 2)
 105             os.kill(pid, 9)
 106     os.system("/etc/init.d/codemux start")