Index: twistd.py
===================================================================
--- twistd.py	(revision 16877)
+++ twistd.py	(working copy)
@@ -8,6 +8,7 @@
 from twisted.application import app, service
 from twisted.scripts import mktap
 from twisted import copyright
+from twisted.plugin import getPlugins
 
 import os, errno, sys
 
@@ -25,6 +26,9 @@
                  "after binding ports, retaining the option to regain "
                  "privileges in cases such as spawning processes. "
                  "Use with caution.)"],
+                ['listlogobservers',None,
+                 "List the available log observers on your system"
+                ]
                ]
 
     optParameters = [
@@ -36,6 +40,9 @@
                       'Chroot to a supplied directory before running'],
                      ['uid', 'u', None, "The uid to run as."],
                      ['gid', 'g', None, "The gid to run as."],
+                     ['logobserver',None,None,
+                      "use a custom logobserver plugin."
+                     ]
                     ]
     zsh_altArgDescr = {"prefix":"Use the given prefix when syslogging (default: twisted)",
                        "pidfile":"Name of the pidfile (default: twistd.pid)",}
@@ -98,14 +105,29 @@
         log.msg("Failed to unlink PID file:")
         log.deferr()
 
-def startLogging(logfilename, sysLog, prefix, nodaemon):
+def getCustomLogger(logObserver):
+    """
+    lookup a custom log plugin and match against the name of the plugin class.
+    """
+    for logger in getPlugins(log.ILogObserver):
+        if logger.__class__.__name__ == logObserver:
+            return logger
+    print 'log plugin not found.  did you try --listlogobservers?'
+    sys.exit()
+    
+
+def startLogging(logfilename, logObserver,sysLog, prefix, nodaemon):
     if logfilename == '-':
         if not nodaemon:
             print 'daemons cannot log to stdout'
             os._exit(1)
         logFile = sys.stdout
     elif sysLog:
-        syslog.startLogging(prefix)
+        if logObserver:
+            print 'logobserver plugin can not be used with syslog'
+            sys.exit()
+        else:
+            syslog.startLogging(prefix)
     elif nodaemon and not logfilename:
         logFile = sys.stdout
     else:
@@ -121,7 +143,12 @@
             signal.signal(signal.SIGUSR1, rotateLog)
         
     if not sysLog:
-        log.startLogging(logFile)
+        if logObserver:
+            customlogger = getCustomLogger(logObserver)
+            customlogger.setFile(logFile)
+            log.startLoggingWithObserver(customlogger.emit,logFile)
+        else:
+            log.startLogging(logFile)
     sys.stdout.flush()
 
 
@@ -181,15 +208,27 @@
     shedPrivileges(config['euid'], uid, gid)
     app.startApplication(application, not config['no_save'])
 
+def checkLogObservers(listobs):
+    if not listobs:
+        return
+    print 'your system has the following log file plugins installed: '
+    any = False
+    for logobs in getPlugins(log.ILogObserver):
+        any = True
+        print '%s:%s' % (logobs.__class__.__name__,repr(logobs))
+    if not any:
+        print 'No log plugins found.'
+    sys.exit()
 
 def runApp(config):
     checkPID(config['pidfile'])
+    checkLogObservers(config['listlogobservers'])
     passphrase = app.getPassphrase(config['encrypted'])
     app.installReactor(config['reactor'])
     config['nodaemon'] = config['nodaemon'] or config['debug']
     oldstdout = sys.stdout
     oldstderr = sys.stderr
-    startLogging(config['logfile'], config['syslog'], config['prefix'],
+    startLogging(config['logfile'], config['logobserver'],config['syslog'], config['prefix'],
                  config['nodaemon'])
     app.initialLog()
     application = app.getApplication(config, passphrase)