Source Code for Module lamson.utils

  1  """ 
  2  Mostly utility functions Lamson uses internally that don't 
  3  really belong anywhere else in the modules.  This module 
  4  is kind of a dumping ground, so if you find something that 
  5  can be improved feel free to work up a patch. 
  6  """ 
  7   
  8  from lamson import server, routing 
  9  import sys, os 
 10  import logging 
 11  import daemon 
 12  from daemon import pidlockfile 
 13  import imp 
 14  import signal 
 15   
 16   
 17 -def import_settings(boot_also, from_dir=None, boot_module="config.boot"): 
 18      """Used to import the settings in a Lamson project.""" 
 19      if from_dir: 
 20          sys.path.append(from_dir) 
 21   
 22      settings = __import__("config.settings", globals(), locals()).settings 
 23   
 24      if boot_also: 
 25          __import__(boot_module, globals(), locals()) 
 26   
 27      return settings 
 28   
 29   
 30 -def daemonize(pid, chdir, chroot, umask, files_preserve=None, do_open=True): 
 31      """ 
 32      Uses python-daemonize to do all the junk needed to make a 
 33      server a server.  It supports all the features daemonize 
 34      has, except that chroot probably won't work at all without 
 35      some serious configuration on the system. 
 36      """ 
 37      context = daemon.DaemonContext() 
 38      context.pidfile = pidlockfile.PIDLockFile(pid) 
 39      context.stdout = open(os.path.join(chdir, "logs/lamson.out"),"a+")                                                                                                        
 40      context.stderr = open(os.path.join(chdir, "logs/lamson.err"),"a+")                                                                                                        
 41      context.files_preserve = files_preserve or [] 
 42      context.working_directory = os.path.expanduser(chdir) 
 43   
 44      if chroot:  
 45          context.chroot_directory = os.path.expanduser(chroot) 
 46      if umask != False: 
 47          context.umask = umask 
 48   
 49      if do_open: 
 50          context.open() 
 51   
 52      return context 
 53   
 54 -def drop_priv(uid, gid): 
 55      """ 
 56      Changes the uid/gid to the two given, you should give utils.daemonize 
 57      0,0 for the uid,gid so that it becomes root, which will allow you to then 
 58      do this. 
 59      """ 
 60      logging.debug("Dropping to uid=%d, gid=%d", uid, gid) 
 61      daemon.daemon.change_process_owner(uid, gid) 
 62      logging.debug("Now running as uid=%d, gid=%d", os.getgid(), os.getuid()) 
 63   
 64   
 65   
 66 -def make_fake_settings(host, port): 
 67      """ 
 68      When running as a logging server we need a fake settings module to work with 
 69      since the logging server can be run in any directory, so there may not be 
 70      a config/settings.py file to import. 
 71      """ 
 72      logging.basicConfig(filename="logs/logger.log", level=logging.DEBUG) 
 73      routing.Router.load(['lamson.handlers.log', 'lamson.handlers.queue']) 
 74      settings = imp.new_module('settings') 
 75      settings.receiver = server.SMTPReceiver(host, port) 
 76      settings.relay = None 
 77      logging.info("Logging mode enabled, will not send email to anyone, just log.") 
 78   
 79      return settings 
 80   
 81 -def check_for_pid(pid, force): 
 82      """Checks if a pid file is there, and if it is sys.exit.  If force given 
 83      then it will remove the file and not exit if it's there.""" 
 84      if os.path.exists(pid): 
 85          if not force: 
 86              print "PID file %s exists, so assuming Lamson is running.  Give -FORCE to force it to start." % pid 
 87              sys.exit(1) 
 88              return # for unit tests mocking sys.exit 
 89          else: 
 90              os.unlink(pid) 
 91   
 92   
 93 -def start_server(pid, force, chroot, chdir, uid, gid, umask, settings_loader): 
 94      """ 
 95      Starts the server by doing a daemonize and then dropping priv 
 96      accordingly.  It will only drop to the uid/gid given if both are given. 
 97      """ 
 98      check_for_pid(pid, force) 
 99   
100      daemonize(pid, chdir, chroot, umask, files_preserve=[]) 
101   
102      sys.path.append(os.getcwd()) 
103   
104      settings = settings_loader() 
105   
106      if uid and gid: 
107          drop_priv(uid, gid)  
108      elif uid or gid: 
109          logging.warning("You probably meant to give a uid and gid, but you gave: uid=%r, gid=%r.  Will not change to any user.", uid, gid) 
110   
111      settings.receiver.start() 
112