Source Code for Module ZenUtils.ZenDaemon

  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__="""ZenDaemon 
 15   
 16  Base class for making deamon programs 
 17   
 18  $Id: ZenDaemon.py,v 1.9 2003/08/29 20:33:10 edahl Exp $""" 
 19   
 20  __version__ = "$Revision: 1.9 $"[11:-2] 
 21   
 22  import sys 
 23  import os 
 24  import pwd 
 25  import signal 
 26  import logging 
 27   
 28  from CmdBase import CmdBase 
 29  from Utils import zenPath, HtmlFormatter 
 30   
 31  # Daemon creation code below based on Recipe by Chad J. Schroeder 
 32  # File mode creation mask of the daemon. 
 33  UMASK = 0022 
 34  # Default working directory for the daemon. 
 35  WORKDIR = "/" 
 36   
 37  # only close stdin/out/err 
 38  MAXFD = 3  
 39   
 40  # The standard I/O file descriptors are redirected to /dev/null by default. 
 41  if (hasattr(os, "devnull")): 
 42     REDIRECT_TO = os.devnull 
 43  else: 
 44     REDIRECT_TO = "/dev/null" 
 45   
 46   
 47 -class ZenDaemon(CmdBase): 
 48   
 49      pidfile = None 
 50       
 51 -    def __init__(self, noopts=0, keeproot=False): 
 52          CmdBase.__init__(self, noopts) 
 53          self.keeproot=keeproot 
 54          self.zenhome = zenPath() 
 55          self.zenvar = zenPath("var") 
 56          if not noopts: 
 57              # These handlers do not get called if run as daemon.  In that 
 58              # case twisted's handlers are called instead. 
 59              # See ticket #1757 
 60              signal.signal(signal.SIGINT, self.sigTerm) 
 61              signal.signal(signal.SIGTERM, self.sigTerm) 
 62              signal.signal(signal.SIGHUP, self.sigTerm) 
 63              if self.options.daemon: 
 64                  self.changeUser() 
 65                  self.becomeDaemon()  
 66   
 67   
 68 -    def setupLogging(self): 
 69          rlog = logging.getLogger() 
 70          rlog.setLevel(logging.WARN) 
 71          mname = self.__class__.__name__ 
 72          self.log = logging.getLogger("zen."+ mname) 
 73          zlog = logging.getLogger("zen") 
 74          zlog.setLevel(self.options.logseverity) 
 75          if self.options.daemon or self.options.logpath: 
 76              if self.options.logpath: 
 77                  if not os.path.isdir(os.path.dirname(self.options.logpath)): 
 78                      raise SystemExit("logpath:%s doesn't exist" % 
 79                                          self.options.logpath) 
 80                  logdir = self.options.logpath 
 81              else: 
 82                  logdir = zenPath("log") 
 83              logfile = os.path.join(logdir, mname.lower()+".log") 
 84              h = logging.FileHandler(logfile) 
 85              h.setFormatter(logging.Formatter( 
 86                  "%(asctime)s %(levelname)s %(name)s: %(message)s", 
 87                  "%Y-%m-%d %H:%M:%S")) 
 88              rlog.addHandler(h) 
 89          else: 
 90              logging.basicConfig() 
 91              if self.options.weblog: 
 92                  [ h.setFormatter(HtmlFormatter()) for h in rlog.handlers ] 
 93   
 94   
 95 -    def changeUser(self): 
 96          if not self.keeproot: 
 97              try: 
 98                  cname = pwd.getpwuid(os.getuid())[0] 
 99                  pwrec = pwd.getpwnam(self.options.uid) 
100                  os.setuid(pwrec.pw_uid) 
101                  os.environ['HOME'] = pwrec.pw_dir 
102              except (KeyError, OSError): 
103                  print >>sys.stderr, "WARN: user:%s not found running as:%s"%( 
104                                      self.options.uid,cname) 
105   
106   
107 -    def becomeDaemon(self): 
108          """Code below comes from the excelent recipe by Chad J. Schroeder. 
109          """ 
110          try: 
111              pid = os.fork() 
112          except OSError, e: 
113              raise Exception, "%s [%d]" % (e.strerror, e.errno) 
114   
115          if (pid == 0):  # The first child. 
116              os.setsid() 
117              try: 
118                  pid = os.fork() # Fork a second child. 
119              except OSError, e: 
120                  raise Exception, "%s [%d]" % (e.strerror, e.errno) 
121   
122              if (pid == 0):      # The second child. 
123                  os.chdir(WORKDIR) 
124                  os.umask(UMASK) 
125              else: 
126                  os._exit(0)     # Exit parent (the first child) of the second child. 
127          else: 
128              os._exit(0) # Exit parent of the first child. 
129   
130          # Iterate through and close all stdin/out/err 
131          for fd in range(0, MAXFD): 
132              try: 
133                  os.close(fd) 
134              except OSError:     # ERROR, fd wasn't open to begin with (ignored) 
135                  pass 
136   
137          os.open(REDIRECT_TO, os.O_RDWR) # standard input (0) 
138          # Duplicate standard input to standard output and standard error. 
139          os.dup2(0, 1)                   # standard output (1) 
140          os.dup2(0, 2)                   # standard error (2) 
141          if os.path.exists(self.zenvar): 
142              myname = sys.argv[0].split(os.sep)[-1] + ".pid" 
143              self.pidfile = os.path.join(self.zenvar, myname) 
144              fp = open(self.pidfile, 'w') 
145              fp.write(str(os.getpid())) 
146              fp.close() 
147          else: 
148              raise SystemExit("ERROR: unable to open pid file %s" % self.pidfile) 
149          return(0) 
150   
151   
152 -    def sigTerm(self, *unused): 
153          # This probably won't be called when running as daemon. 
154          # See ticket #1757 
155          stop = getattr(self, "stop", None) 
156          if callable(stop): stop() 
157          if self.pidfile and os.path.exists(self.pidfile): 
158              self.log.info("delete pidfile %s", self.pidfile) 
159              os.remove(self.pidfile) 
160          self.log.info('Daemon %s shutting down' % self.__class__.__name__) 
161          raise SystemExit 
162   
163   
164 -    def buildOptions(self): 
165          CmdBase.buildOptions(self) 
166          self.parser.add_option('--uid',dest='uid',default="zenoss", 
167                  help='user to become when running default:zenoss') 
168          self.parser.add_option('-c', '--cycle',dest='cycle', 
169                  action="store_true", default=False, 
170                  help="Cycle continuously on cycleInterval from zope") 
171          self.parser.add_option('-D', '--daemon', default=False, 
172                  dest='daemon',action="store_true", 
173                  help="Become a unix daemon") 
174          self.parser.add_option('--weblog', default=False, 
175                  dest='weblog',action="store_true", 
176                  help="output log info in html table format") 
177