Products.ZenUtils.ZenDaemon

47 """ 48 Base class for creating daemons 49 """ 50 51 pidfile = None 52

53 - def __init__(self, noopts=0, keeproot=False):

54 """ 55 Initializer that takes care of basic daemon options. 56 Creates a PID file. 57 """ 58 super(ZenDaemon, self).__init__(noopts) 59 self.pidfile = None 60 self.keeproot=keeproot 61 self.reporter = None 62 self.fqdn = socket.getfqdn() 63 from twisted.internet import reactor 64 reactor.addSystemEventTrigger('before', 'shutdown', self.sigTerm) 65 if not noopts: 66 if self.options.daemon: 67 self.changeUser() 68 self.becomeDaemon() 69 if self.options.daemon or self.options.watchdogPath: 70 try: 71 self.writePidFile() 72 except OSError: 73 msg= "ERROR: unable to open PID file %s" % \ 74 (self.pidfile or '(unknown)') 75 raise SystemExit(msg) 76 77 if self.options.watchdog and not self.options.watchdogPath: 78 self.becomeWatchdog()

79

80 - def openPrivilegedPort(self, *address):

81 """Execute under zensocket, providing the args to zensocket""" 82 zensocket = binPath('zensocket') 83 cmd = [zensocket, zensocket] + list(address) + ['--'] + \ 84 [sys.executable] + sys.argv + \ 85 ['--useFileDescriptor=$privilegedSocket'] 86 os.execlp(*cmd)

87 88

89 - def writePidFile(self):

90 """ 91 Write the PID file to disk 92 """ 93 myname = sys.argv[0].split(os.sep)[-1] 94 if myname.endswith('.py'): myname = myname[:-3] 95 monitor = getattr(self.options, 'monitor', 'localhost') 96 myname = "%s-%s.pid" % (myname, monitor) 97 if self.options.watchdog and not self.options.watchdogPath: 98 self.pidfile = zenPath("var", 'watchdog-%s' % myname) 99 else: 100 self.pidfile = zenPath("var", myname) 101 fp = open(self.pidfile, 'w') 102 fp.write(str(os.getpid())) 103 fp.close()

104

105 - def setupLogging(self):

106 """ 107 Create formating for log entries and set default log level 108 """ 109 rlog = logging.getLogger() 110 rlog.setLevel(logging.WARN) 111 if hasattr(self, 'mname'): mname = self.mname 112 else: mname = self.__class__.__name__ 113 self.log = logging.getLogger("zen."+ mname) 114 zlog = logging.getLogger("zen") 115 zlog.setLevel(self.options.logseverity) 116 if self.options.watchdogPath or \ 117 self.options.daemon: 118 logdir = self.checkLogpath() 119 if not logdir: 120 logdir = zenPath("log") 121 logfile = os.path.join(logdir, mname.lower()+".log") 122 maxBytes = self.options.maxLogKiloBytes * 1024 123 backupCount = self.options.maxBackupLogs 124 h = logging.handlers.RotatingFileHandler(filename=logfile, maxBytes=maxBytes, backupCount=backupCount) 125 h.setFormatter(logging.Formatter( 126 "%(asctime)s %(levelname)s %(name)s: %(message)s")) 127 rlog.addHandler(h) 128 else: 129 logging.basicConfig() 130 if self.options.weblog: 131 [ h.setFormatter(HtmlFormatter()) for h in rlog.handlers ] 132 else: 133 f = logging.Formatter("%(asctime)s %(levelname)s %(name)s: %(message)s") 134 [ h.setFormatter(f) for h in rlog.handlers ] 135 136 # Allow the user to dynamically lower and raise the logging 137 # level without restarts. 138 import signal 139 try: 140 signal.signal(signal.SIGUSR1, self.sighandler_USR1) 141 except ValueError: 142 # If we get called multiple times, this will generate an exception: 143 # ValueError: signal only works in main thread 144 # Ignore it as we've already set up the signal handler. 145 pass

146

147 - def sighandler_USR1(self, signum, frame):

148 """ 149 Switch to debug level if signaled by the user, and to 150 default when signaled again. 151 """ 152 levelNames = { 153 logging.DEBUG:"DEBUG", 154 logging.INFO:"INFO", 155 logging.WARN:"WARN", 156 logging.ERROR:"ERROR", 157 logging.CRITICAL:"CRITICAL", 158 } 159 log = logging.getLogger('zen') 160 currentLevel = log.getEffectiveLevel() 161 if currentLevel == logging.DEBUG: 162 log.setLevel(self.options.logseverity) 163 log.info("Restoring logging level back to %s (%d)", 164 levelNames.get(self.options.logseverity, 165 "unknown"), 166 self.options.logseverity) 167 else: 168 log.setLevel(logging.DEBUG) 169 log.info("Setting logging level to DEBUG")

170 171

172 - def changeUser(self):

173 """ 174 Switch identity to the appropriate Unix user 175 """ 176 if not self.keeproot: 177 try: 178 cname = pwd.getpwuid(os.getuid())[0] 179 pwrec = pwd.getpwnam(self.options.uid) 180 os.setuid(pwrec.pw_uid) 181 os.environ['HOME'] = pwrec.pw_dir 182 except (KeyError, OSError): 183 print >>sys.stderr, "WARN: user:%s not found running as:%s"%( 184 self.options.uid,cname)

185 186

187 - def becomeDaemon(self):

188 """Code below comes from the excellent recipe by Chad J. Schroeder. 189 """ 190 try: 191 pid = os.fork() 192 except OSError, e: 193 raise Exception( "%s [%d]" % (e.strerror, e.errno) ) 194 195 if (pid == 0): # The first child. 196 os.setsid() 197 try: 198 pid = os.fork() # Fork a second child. 199 except OSError, e: 200 raise Exception( "%s [%d]" % (e.strerror, e.errno) ) 201 202 if (pid == 0): # The second child. 203 os.chdir(WORKDIR) 204 os.umask(UMASK) 205 else: 206 os._exit(0) # Exit parent (the first child) of the second child. 207 else: 208 os._exit(0) # Exit parent of the first child. 209 210 # Iterate through and close all stdin/out/err 211 for fd in range(0, MAXFD): 212 try: 213 os.close(fd) 214 except OSError: # ERROR, fd wasn't open to begin with (ignored) 215 pass 216 217 os.open(REDIRECT_TO, os.O_RDWR) # standard input (0) 218 # Duplicate standard input to standard output and standard error. 219 os.dup2(0, 1) # standard output (1) 220 os.dup2(0, 2) # standard error (2)

221 222

223 - def sigTerm(self, signum=None, frame=None):

224 """ 225 Signal handler for the SIGTERM signal. 226 """ 227 # This probably won't be called when running as daemon. 228 # See ticket #1757 229 from Products.ZenUtils.Utils import unused 230 unused(signum, frame) 231 stop = getattr(self, "stop", None) 232 if callable(stop): stop() 233 if self.pidfile and os.path.exists(self.pidfile): 234 self.log.info("Deleting PID file %s ...", self.pidfile) 235 os.remove(self.pidfile) 236 self.log.info('Daemon %s shutting down' % self.__class__.__name__) 237 raise SystemExit

238 239

240 - def watchdogCycleTime(self):

241 """ 242 Return our cycle time (in minutes) 243 244 @return: cycle time 245 @rtype: integer 246 """ 247 # time between child reports: default to 2x the default cycle time 248 default = 1200 249 cycleTime = getattr(self.options, 'cycleTime', default) 250 if not cycleTime: 251 cycleTime = default 252 return cycleTime

253

254 - def watchdogStartTimeout(self):

255 """ 256 Return our watchdog start timeout (in minutes) 257 258 @return: start timeout 259 @rtype: integer 260 """ 261 # Default start timeout should be cycle time plus a couple of minutes 262 default = self.watchdogCycleTime() + 120 263 startTimeout = getattr(self.options, 'starttimeout', default) 264 if not startTimeout: 265 startTimeout = default 266 return startTimeout

267 268

269 - def watchdogMaxRestartTime(self):

270 """ 271 Return our watchdog max restart time (in minutes) 272 273 @return: maximum restart time 274 @rtype: integer 275 """ 276 default = 600 277 maxTime = getattr(self.options, 'maxRestartTime', default) 278 if not maxTime: 279 maxTime = default 280 return default

281 282

283 - def becomeWatchdog(self):

284 """ 285 Watch the specified daemon and restart it if necessary. 286 """ 287 from Products.ZenUtils.Watchdog import Watcher, log 288 log.setLevel(self.options.logseverity) 289 cmd = sys.argv[:] 290 if '--watchdog' in cmd: 291 cmd.remove('--watchdog') 292 if '--daemon' in cmd: 293 cmd.remove('--daemon') 294 295 socketPath = '%s/.%s-watchdog-%d' % ( 296 zenPath('var'), self.__class__.__name__, os.getpid()) 297 298 cycleTime = self.watchdogCycleTime() 299 startTimeout = self.watchdogStartTimeout() 300 maxTime = self.watchdogMaxRestartTime() 301 self.log.debug("Watchdog cycleTime=%d startTimeout=%d maxTime=%d", 302 cycleTime, startTimeout, maxTime) 303 304 watchdog = Watcher(socketPath, 305 cmd, 306 startTimeout, 307 cycleTime, 308 maxTime) 309 watchdog.run() 310 sys.exit(0)

311

312 - def niceDoggie(self, timeout):

313 # defer creation of the reporter until we know we're not going 314 # through zensocket or other startup that results in closing 315 # this socket 316 if not self.reporter and self.options.watchdogPath: 317 from Watchdog import Reporter 318 self.reporter = Reporter(self.options.watchdogPath) 319 if self.reporter: 320 self.reporter.niceDoggie(timeout)

321

322 - def buildOptions(self):

323 """ 324 Standard set of command-line options. 325 """ 326 CmdBase.buildOptions(self) 327 self.parser.add_option('--uid',dest='uid',default="zenoss", 328 help='User to become when running default:zenoss') 329 self.parser.add_option('-c', '--cycle',dest='cycle', 330 action="store_true", default=False, 331 help="Cycle continuously on cycleInterval from Zope") 332 self.parser.add_option('-D', '--daemon', default=False, 333 dest='daemon',action="store_true", 334 help="Launch into the background") 335 self.parser.add_option('--weblog', default=False, 336 dest='weblog',action="store_true", 337 help="output log info in HTML table format") 338 self.parser.add_option('--watchdog', default=False, 339 dest='watchdog', action="store_true", 340 help="Run under a supervisor which will restart it") 341 self.parser.add_option('--watchdogPath', default=None, 342 dest='watchdogPath', 343 help="The path to the watchdog reporting socket") 344 self.parser.add_option('--starttimeout', 345 dest='starttimeout', 346 type="int", 347 help="Wait seconds for initial heartbeat")

Source Code for Module Products.ZenUtils.ZenDaemon