用python编写daemon监控进程并自动恢复

我会带着你远行 2022-08-19 12:21 122阅读 0赞

**用python编写daemon监控进程并自动恢复**

**     下面这个程序是用于python编写daemon监控进程并自动恢复，参考http://pythonhosted.org/KiTT/\_modules/kitt/daemon.html**

#!/usr/bin/env python
    
    import sys, os, time, atexit
    from signal import SIGTERM
    
    
     
      
      
       [docs]
      
       class 
      
       Daemon
      
       :
        
      
       """
    
      
       A generic daemon class.
    
    
      
       Usage: subclass the Daemon class and override the run() method
    
      
       """
        
      
       def 
      
       __init__
      
       (
      
       self
      
       , 
      
       pidfile
      
       , 
      
       stdin
      
       =
      
       '/dev/null'
      
       , 
      
       stdout
      
       =
      
       '/dev/null'
      
       , 
      
       stderr
      
       =
      
       '/dev/null'
      
       , 
      
       args
      
       =
      
       None
      
       ):
            
      
       self
      
       .
      
       stdin 
      
       = 
      
       stdin
            
      
       self
      
       .
      
       stdout 
      
       = 
      
       stdout
            
      
       self
      
       .
      
       stderr 
      
       = 
      
       stderr
            
      
       self
      
       .
      
       pidfile 
      
       = 
      
       pidfile
            
      
       self
      
       .
      
       args 
      
       = 
      
       args
    
    
      
       [docs] def daemonize ( self ): """ do the UNIX double-fork magic, see Stevens' "Advanced Programming in the UNIX Environment" for details (ISBN 0201563177) http://www.erlenstar.demon.co.uk/unix/faq_2.html#SEC16 """ try : pid = os . fork () if pid > 0 : # exit first parent sys . exit ( 0 ) except OSError , e : sys . stderr . write ( "fork #1 failed: %d ( %s ) \n " % ( e . errno , e . strerror )) sys . exit ( 1 ) # decouple from parent environment os . chdir ( "/" ) os . setsid () os . umask ( 0 ) # do second fork try : pid = os . fork () if pid > 0 : # exit from second parent sys . exit ( 0 ) except OSError , e : sys . stderr . write ( "fork #2 failed: %d ( %s ) \n " % ( e . errno , e . strerror )) sys . exit ( 1 ) # redirect standard file descriptors sys . stdout . flush () sys . stderr . flush () si = file ( self . stdin , 'r' ) so = file ( self . stdout , 'a+' ) se = file ( self . stderr , 'a+' , 0 ) os . dup2 ( si . fileno (), sys . stdin . fileno ()) os . dup2 ( so . fileno (), sys . stdout . fileno ()) if type ( sys . stderr ) is file : os . dup2 ( se . fileno (), sys . stderr . fileno ()) # write pidfile atexit . register ( self . delpid ) pid = str ( os . getpid ()) file ( self . pidfile , 'w+' ) . write ( " %s \n " % pid ) 
    
      
       [docs] def delpid ( self ): os . remove ( self . pidfile ) 
    
      
       [docs] def start ( self ): """ Start the daemon """ # Check for a pidfile to see if the daemon already runs try : pf = file ( self . pidfile , 'r' ) pid = int ( pf . read () . strip ()) pf . close () except IOError : pid = None if pid : message = "pidfile %s already exist. Daemon already running? \n " sys . stderr . write ( message % self . pidfile ) sys . exit ( 1 ) # Start the daemon self . daemonize () self . run () 
    
      
       [docs] def stop ( self ): """ Stop the daemon """ # Get the pid from the pidfile try : pf = file ( self . pidfile , 'r' ) pid = int ( pf . read () . strip ()) pf . close () except IOError : pid = None if not pid : message = "pidfile %s does not exist. Daemon not running? \n " sys . stderr . write ( message % self . pidfile ) return # not an error in a restart # Try killing the daemon process try : while 1 : os . kill ( pid , SIGTERM ) time . sleep ( 0.1 ) except OSError , err : err = str ( err ) if err . find ( "No such process" ) > 0 : if os . path . exists ( self . pidfile ): os . remove ( self . pidfile ) else : print str ( err ) sys . exit ( 1 ) 
    
      
       [docs] def restart ( self ): """ Restart the daemon """ self . stop () self . start () 
    
      
       [docs] def run ( self ): """ You should override this method when you subclass Daemon. It will be called after the process has been daemonized by start() or restart(). """