前言
最近项目中遇到一个用于监控日志文件的Python包pyinotify,结合自己的项目经验和网上的一些资料总结一下,总的原理是利用pyinotify模块监控日志文件夹,当日志到来的情况下,触发相应的函数进行处理,处理完毕后删除日志文件的过程,下面就着重介绍下pyinotify
pyinotify
Pyinotify是一个Python模块,用来监测文件系统的变化。 Pyinotify依赖于Linux内核的功能—inotify(内核2.6.13合并)。 inotify的是一个事件驱动的通知器,其通知接口通过三个系统调用从内核空间到用户空间。pyinotify结合这些系统调用,并提供一个顶级的抽象和一个通用的方式来处理这些功能。
pyinotify 说百了就是通过 调用系统的inotify来实现通知的
inotify 既可以监视文件,也可以监视目录
Inotify 使用系统调用而非 SIGIO 来通知文件系统事件。
Inotify 可以监视的文件系统事件包括:
Event Name
Is an Event
Description
IN_ACCESS
Yes
file was accessed.
IN_ATTRIB
Yes
metadata changed.
IN_CLOSE_NOWRITE
Yes
unwrittable file was closed.
IN_CLOSE_WRITE
Yes
writtable file was closed.
IN_CREATE
Yes
file/dir was created in watched directory.
IN_DELETE
Yes
file/dir was deleted in watched directory.
IN_DELETE_SELF
Yes
自删除,即一个可执行文件在执行时删除自己
IN_DONT_FOLLOW
No
don't follow a symlink (lk 2.6.15).
IN_IGNORED
Yes
raised on watched item removing. Probably useless for you, prefer instead IN_DELETE*.
IN_ISDIR
No
event occurred against directory. It is always piggybacked to an event. The Event structure automatically provide this information (via .is_dir)
IN_MASK_ADD
No
to update a mask without overwriting the previous value (lk 2.6.14). Useful when updating a watch.
IN_MODIFY
Yes
file was modified.
IN_MOVE_SELF
Yes
自移动,即一个可执行文件在执行时移动自己
IN_MOVED_FROM
Yes
file/dir in a watched dir was moved from X. Can trace the full move of an item when IN_MOVED_TO is available too, in this case if the moved item is itself watched, its path will be updated (see IN_MOVE_SELF).
IN_MOVED_TO
Yes
file/dir was moved to Y in a watched dir (see IN_MOVE_FROM).
IN_ONLYDIR
No
only watch the path if it is a directory (lk 2.6.15). Usable when calling .add_watch.
IN_OPEN
Yes
file was opened.
IN_Q_OVERFLOW
Yes
event queued overflowed. This event doesn't belongs to any particular watch.
IN_UNMOUNT
Yes
宿主文件系统被 umount
IN_ACCESS,即文件被访问
IN_MODIFY,文件被write
IN_ATTRIB,文件属性被修改,如chmod、chown、touch等
IN_CLOSE_WRITE,可写文件被close
IN_CLOSE_NOWRITE,不可写文件被close
IN_OPEN,文件被open
IN_MOVED_FROM,文件被移走,如mv
IN_MOVED_TO,文件被移来,如mv、cp
IN_CREATE,创建新文件
IN_DELETE,文件被删除,如rm
IN_DELETE_SELF,自删除,即一个可执行文件在执行时删除自己
IN_MOVE_SELF,自移动,即一个可执行文件在执行时移动自己
IN_UNMOUNT,宿主文件系统被umount
IN_CLOSE,文件被关闭,等同于(IN_CLOSE_WRITE | IN_CLOSE_NOWRITE)
IN_MOVE,文件被移动,等同于(IN_MOVED_FROM | IN_MOVED_TO)
pyinotify使用例子
#!/usr/bin/python
# coding:utf-8
import os
from pyinotify import WatchManager, Notifier,ProcessEvent,IN_DELETE, IN_CREATE,IN_MODIFY
class EventHandler(ProcessEvent):
"""事件处理"""
def process_IN_CREATE(self, event):
print "Create file: %s " % os.path.join(event.path,event.name)
def process_IN_DELETE(self, event):
print "Delete file: %s " % os.path.join(event.path,event.name)
def process_IN_MODIFY(self, event):
print "Modify file: %s " % os.path.join(event.path,event.name)
def FSMonitor(path='.'):
wm = WatchManager()
mask = IN_DELETE | IN_CREATE |IN_MODIFY
notifier = Notifier(wm, EventHandler())
wm.add_watch(path, mask,auto_add=True,rec=True)
print 'now starting monitor %s'%(path)
while True:
try:
notifier.process_events()
if notifier.check_events():
notifier.read_events()
except KeyboardInterrupt:
notifier.stop()
break
if __name__ == "__main__":
FSMonitor('/root/softpython/apk_url')