Source Code for Module ZenUtils.ConfDaemon

  1  ########################################################################### 
  2  # 
  3  # This program is part of Zenoss Core, an open source monitoring platform. 
  4  # Copyright (C) 2007, Zenoss Inc. 
  5  # 
  6  # This program is free software; you can redistribute it and/or modify it 
  7  # under the terms of the GNU General Public License version 2 as published by 
  8  # the Free Software Foundation. 
  9  # 
 10  # For complete information please visit: http://www.zenoss.com/oss/ 
 11  # 
 12  ########################################################################### 
 13   
 14  __doc__="""ConfDaemon 
 15   
 16  Base class for makeing deamon programs 
 17   
 18  $Id: ConfDaemon.py,v 1.9 2003/08/29 20:33:10 edahl Exp $""" 
 19   
 20  __version__ = "$Revision: 1.9 $"[11:-2] 
 21   
 22  import signal 
 23  import os 
 24  import sys 
 25  import socket 
 26  import time 
 27   
 28  from CmdBase import CmdBase 
 29  from Utils import zenPath 
 30   
 31 -class ConfDaemon(CmdBase): 
 32       
 33 -    def __init__(self): 
 34          CmdBase.__init__(self) 
 35          signal.signal(signal.SIGINT, self.sigTerm) 
 36          signal.signal(signal.SIGTERM, self.sigTerm) 
 37          if self.options.daemon and sys.platform != 'win32': 
 38              self.becomeDaemon()  
 39          self.dnstries = 3 
 40          self.forwarddnscache = {} 
 41          self.reversednscache = {} 
 42   
 43 -    def becomeDaemon(self): 
 44          """fork twice to become a daemon""" 
 45          pid = 0 
 46          try: 
 47              pid = os.fork() 
 48              if pid > 0: 
 49                  sys.exit(0) 
 50          except OSError, e: 
 51              print >>sys.stderr, ("fork #1 failed: %d (%s)" %  
 52                      (e.errno, e.strerror)) 
 53          os.chdir("/") 
 54          os.setsid() 
 55          os.umask(0) 
 56          try: 
 57              pid = os.fork() 
 58              if pid > 0: 
 59                  sys.exit(0) 
 60          except OSError, e: 
 61              print >>sys.stderr, ("fork #2 failed: %d (%s)" %  
 62                      (e.errno, e.strerror)) 
 63          myname = sys.argv[0].split(os.sep)[-1] + ".pid" 
 64          varhome = zenPath('var') 
 65          pidfile = os.path.join(varhome, myname) 
 66          if os.path.exists(varhome): 
 67              file = open(pidfile, 'w') 
 68              file.write(str(os.getpid())) 
 69              file.close() 
 70          else: 
 71              print "ERROR: unable to open pid file %s" % pidfile 
 72              sys.exit(1)  
 73   
 74   
 75 -    def forwardDnsLookup(self, hostname): 
 76          """try the forward lookup dnstries times if it fails look in cache""" 
 77          try: 
 78              ip = self._dnsLookup(socket.gethostbyname, hostname) 
 79              self.forwarddnscache[hostname] = ip 
 80              return ip 
 81          except socket.error: 
 82              if self.forwarddnscache.has_key(hostname): 
 83                  return self.forwarddnscache[hostname] 
 84              else: 
 85                  raise 
 86   
 87   
 88 -    def reverseDnsLookup(self, addr): 
 89          """try the reverse lookup dnstries times if it fails look in cache""" 
 90          try: 
 91              ip = self._dsnLookup(socket.gethostbyaddr, addr) 
 92              self.reversednscache[addr] = ip 
 93              return ip 
 94          except socket.error: 
 95              if self.reversednscache.has_key(addr): 
 96                  return self.reversednscache[addr] 
 97              else: 
 98                  raise 
 99   
100   
101 -    def _dnsLookup(self, function, target): 
102          """try dns lookup dnstries times""" 
103          ip = None 
104          i=0 
105          while 1:  
106              try: 
107                  i+=1 
108                  ip = function(target) 
109              except socket.error: 
110                  if i > self.getDnsTries(): 
111                      raise  
112              if ip: break 
113          return ip 
114           
115   
116 -    def getDnsTries(self): 
117          if not hasattr(self, 'dnstries'): 
118              self.dnstries=3 
119          return self.dnstries 
120   
121           
122 -    def sigTerm(self, signum, frame): 
123          self.log.info('Daemon %s shutting down' % self.__class__.__name__) 
124          sys.exit(0) 
125   
126   
127   
128 -    def getConfig(self): 
129          """handle errors when loading config from server 
130          we try configtries times if no previous config is found""" 
131          for i in range(self.options.configtries): 
132              try: 
133                  self.loadConfig() 
134                  return 
135              except SystemExit: raise 
136              except: 
137                  if self.validConfig(): 
138                      self.log.exception( 
139                      "configuration load exception using previous configuration") 
140                      return 
141                  else: 
142                      self.log.exception('config load failed') 
143                      if i <= (self.options.configtries - 2): 
144                          self.log.warn( 
145                              "initial config load failed will retry") 
146                          time.sleep(self.options.configsleep) 
147                      else: 
148                          self.log.critical( 
149                              "initial config load failed %d times exiting" 
150                                      % self.options.configtries) 
151                          sys.exit(2) 
152   
153   
154 -    def buildOptions(self): 
155          CmdBase.buildOptions(self) 
156          self.parser.add_option('-c', '--cycle', 
157                      dest='cycle', 
158                      default=0, 
159                      action="store_true", 
160                      help="Cycle continuously on cycleInterval from zope") 
161          self.parser.add_option('-d', '--daemon', 
162                      dest='daemon', 
163                      default=0, 
164                      action="store_true", 
165                      help="Become a unix daemon") 
166          self.parser.add_option('-T', '--configtries', 
167                      dest='configtries', 
168                      default=5, 
169                      action="store", 
170                      help="How many times to retry config connection") 
171          self.parser.add_option('-S', '--configsleep', 
172                      dest='configsleep', 
173                      default=20, 
174                      action="store", 
175                      help="How long to sleep between config connections") 
176