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# -*- test-case-name: twisted.test.test_twistd -*- # Copyright (c) 2001-2009 Twisted Matrix Laboratories. # See LICENSE for details.
import os, errno, sys
from twisted.python import log, syslog, logfile from twisted.python.util import switchUID, uidFromString, gidFromString from twisted.application import app, service from twisted import copyright
def _umask(value): return int(value, 8)
class ServerOptions(app.ServerOptions): synopsis = "Usage: twistd [options]"
optFlags = [['nodaemon','n', "don't daemonize, don't use default umask of 0077"], ['originalname', None, "Don't try to change the process name"], ['syslog', None, "Log to syslog, not to file"], ['euid', '', "Set only effective user-id rather than real user-id. " "(This option has no effect unless the server is running as " "root, in which case it means not to shed all privileges " "after binding ports, retaining the option to regain " "privileges in cases such as spawning processes. " "Use with caution.)"], ]
optParameters = [ ['prefix', None,'twisted', "use the given prefix when syslogging"], ['pidfile','','twistd.pid', "Name of the pidfile"], ['chroot', None, None, 'Chroot to a supplied directory before running'], ['uid', 'u', None, "The uid to run as.", uidFromString], ['gid', 'g', None, "The gid to run as.", gidFromString], ['umask', None, None, "The (octal) file creation mask to apply.", _umask], ] zsh_altArgDescr = {"prefix":"Use the given prefix when syslogging (default: twisted)", "pidfile":"Name of the pidfile (default: twistd.pid)",} #zsh_multiUse = ["foo", "bar"] #zsh_mutuallyExclusive = [("foo", "bar"), ("bar", "baz")] zsh_actions = {"pidfile":'_files -g "*.pid"', "chroot":'_dirs'} zsh_actionDescr = {"chroot":"chroot directory"}
def opt_version(self): """Print version information and exit. """ print 'twistd (the Twisted daemon) %s' % copyright.version print copyright.copyright sys.exit()
def postOptions(self): app.ServerOptions.postOptions(self) if self['pidfile']: self['pidfile'] = os.path.abspath(self['pidfile'])
def checkPID(pidfile): if not pidfile: return if os.path.exists(pidfile): try: pid = int(open(pidfile).read()) except ValueError: sys.exit('Pidfile %s contains non-numeric value' % pidfile) try: os.kill(pid, 0) except OSError, why: if why[0] == errno.ESRCH: # The pid doesnt exists. log.msg('Removing stale pidfile %s' % pidfile, isError=True) os.remove(pidfile) else: sys.exit("Can't check status of PID %s from pidfile %s: %s" % (pid, pidfile, why[1])) else: sys.exit("""\ Another twistd server is running, PID %s\n This could either be a previously started instance of your application or a different application entirely. To start a new one, either run it in some other directory, or use the --pidfile and --logfile parameters to avoid clashes. """ % pid)
class UnixAppLogger(app.AppLogger): """ A logger able to log to syslog, to files, and to stdout.
@ivar _syslog: A flag indicating whether to use syslog instead of file logging. @type _syslog: C{bool}
@ivar _syslogPrefix: If C{sysLog} is C{True}, the string prefix to use for syslog messages. @type _syslogPrefix: C{str}
@ivar _nodaemon: A flag indicating the process will not be daemonizing. @type _nodaemon: C{bool} """
def __init__(self, options): app.AppLogger.__init__(self, options) self._syslog = options.get("syslog", False) self._syslogPrefix = options.get("prefix", "") self._nodaemon = options.get("nodaemon", False)
def _getLogObserver(self): """ Create and return a suitable log observer for the given configuration.
The observer will go to syslog using the prefix C{_syslogPrefix} if C{_syslog} is true. Otherwise, it will go to the file named C{_logfilename} or, if C{_nodaemon} is true and C{_logfilename} is C{"-"}, to stdout.
@return: An object suitable to be passed to C{log.addObserver}. """ if self._syslog: return syslog.SyslogObserver(self._syslogPrefix).emit
if self._logfilename == '-': if not self._nodaemon: sys.exit('Daemons cannot log to stdout, exiting!') logFile = sys.stdout elif self._nodaemon and not self._logfilename: logFile = sys.stdout else: if not self._logfilename: self._logfilename = 'twistd.log' logFile = logfile.LogFile.fromFullPath(self._logfilename) try: import signal except ImportError: pass else: # Override if signal is set to None or SIG_DFL (0) if not signal.getsignal(signal.SIGUSR1): def rotateLog(signal, frame): from twisted.internet import reactor reactor.callFromThread(logFile.rotate) signal.signal(signal.SIGUSR1, rotateLog) return log.FileLogObserver(logFile).emit
def daemonize(): # See http://www.erlenstar.demon.co.uk/unix/faq_toc.html#TOC16 if os.fork(): # launch child and... os._exit(0) # kill off parent os.setsid() if os.fork(): # launch child and... os._exit(0) # kill off parent again. null = os.open('/dev/null', os.O_RDWR) for i in range(3): try: os.dup2(null, i) except OSError, e: if e.errno != errno.EBADF: raise os.close(null)
def launchWithName(name): if name and name != sys.argv[0]: exe = os.path.realpath(sys.executable) log.msg('Changing process name to ' + name) os.execv(exe, [name, sys.argv[0], '--originalname'] + sys.argv[1:])
class UnixApplicationRunner(app.ApplicationRunner): """ An ApplicationRunner which does Unix-specific things, like fork, shed privileges, and maintain a PID file. """ loggerFactory = UnixAppLogger
def preApplication(self): """ Do pre-application-creation setup. """ checkPID(self.config['pidfile']) self.config['nodaemon'] = (self.config['nodaemon'] or self.config['debug']) self.oldstdout = sys.stdout self.oldstderr = sys.stderr
def postApplication(self): """ To be called after the application is created: start the application and run the reactor. After the reactor stops, clean up PID files and such. """ self.startApplication(self.application) self.startReactor(None, self.oldstdout, self.oldstderr) self.removePID(self.config['pidfile'])
def removePID(self, pidfile): """ Remove the specified PID file, if possible. Errors are logged, not raised.
@type pidfile: C{str} @param pidfile: The path to the PID tracking file. """ if not pidfile: return try: os.unlink(pidfile) except OSError, e: if e.errno == errno.EACCES or e.errno == errno.EPERM: log.msg("Warning: No permission to delete pid file") else: log.err(e, "Failed to unlink PID file") except: log.err(None, "Failed to unlink PID file")
def setupEnvironment(self, chroot, rundir, nodaemon, umask, pidfile): """ Set the filesystem root, the working directory, and daemonize.
@type chroot: C{str} or L{NoneType} @param chroot: If not None, a path to use as the filesystem root (using L{os.chroot}).
@type rundir: C{str} @param rundir: The path to set as the working directory.
@type nodaemon: C{bool} @param nodaemon: A flag which, if set, indicates that daemonization should not be done.
@type umask: C{int} or L{NoneType} @param umask: The value to which to change the process umask.
@type pidfile: C{str} or L{NoneType} @param pidfile: If not C{None}, the path to a file into which to put the PID of this process. """ daemon = not nodaemon
if chroot is not None: os.chroot(chroot) if rundir == '.': rundir = '/' os.chdir(rundir) if daemon and umask is None: umask = 077 if umask is not None: os.umask(umask) if daemon: daemonize() if pidfile: f = open(pidfile,'wb') f.write(str(os.getpid())) f.close()
def shedPrivileges(self, euid, uid, gid): """ Change the UID and GID or the EUID and EGID of this process.
@type euid: C{bool} @param euid: A flag which, if set, indicates that only the I{effective} UID and GID should be set.
@type uid: C{int} or C{NoneType} @param uid: If not C{None}, the UID to which to switch.
@type gid: C{int} or C{NoneType} @param gid: If not C{None}, the GID to which to switch. """ if uid is not None or gid is not None: switchUID(uid, gid, euid) extra = euid and 'e' or '' log.msg('set %suid/%sgid %s/%s' % (extra, extra, uid, gid))
def startApplication(self, application): """ Configure global process state based on the given application and run the application.
@param application: An object which can be adapted to L{service.IProcess} and L{service.IService}. """ process = service.IProcess(application) if not self.config['originalname']: launchWithName(process.processName) self.setupEnvironment( self.config['chroot'], self.config['rundir'], self.config['nodaemon'], self.config['umask'], self.config['pidfile'])
service.IService(application).privilegedStartService()
uid, gid = self.config['uid'], self.config['gid'] if uid is None: uid = process.uid if gid is None: gid = process.gid
self.shedPrivileges(self.config['euid'], uid, gid) app.startApplication(application, not self.config['no_save'])
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