#!/usr/bin/env python
#coding: utf-8

from __future__ import division
import os

LOG_FILE = '/data0/logs/nginx/xxxx-access_log'
POSITION_FILE = '/tmp/position.log'
STATUS_FILE = '/tmp/http_status'
#crontab 执行时间
CRON_TIME = 300

def get_position():
 #第一次读取日志文件，POSITION_FILE为空
 if not os.path.exists(POSITION_FILE):
  start_position = str(0)
  end_position = str(os.path.getsize(LOG_FILE))
  fh = open(POSITION_FILE,'w')
  fh.write('start_position: %s\n' % start_position)
  fh.write('end_position: %s\n' % end_position)
  fh.close()
  os._exit(1)
 else:
  fh = open(POSITION_FILE)
  se = fh.readlines()
  fh.close()
  #其他意外情况导致POSITION_FILE内容不是两行
  if len(se) != 2:
   os.remove(POSITION_FILE)
   os._exit(1)
  last_start_position,last_end_position = [item.split(':')[1].strip() for item in se]
  start_position = last_end_position
  end_position = str(os.path.getsize(LOG_FILE))
  #日志轮转导致start_position > end_position
  #print start_position,end_position
  if start_position > end_position:
   start_position = 0
  #日志停止滚动时
  elif start_position == end_position:
   os._exit(1)
  #print start_position,end_position
  fh = open(POSITION_FILE,'w')
  fh.write('start_position: %s\n' % start_position)
  fh.write('end_position: %s\n' % end_position)
  fh.close()
  return map(int,[start_position,end_position])

def write_status(content):
 fh = open(STATUS_FILE,'w')
 fh.write(content)
 fh.close()

def handle_log(start_position,end_position):
 log = open(LOG_FILE)
 log.seek(start_position,0)
 status_2xx,status_403,status_404,status_500,status_502,status_503,status_504,status_all,rt,bandwidth = 0,0,0,0,0,0,0,0,0,0
 while True:
  current_position = log.tell()
  if current_position >= end_position:
   break
  line = log.readline()
  line = line.split(' ')
  host,request_time,time_local,status,bytes_sent = line[1],line[3],line[5],line[10],line[11]
  #print host,request_time,time_local,status,bytes_sent
  status_all += 1
  try:
   rt += float(request_time.strip('s'))
   bandwidth += int(bytes_sent)
  except:
   pass
  if status == '200' or status == '206':
   status_2xx += 1
  elif status == '403':
   status_403 += 1
  elif status == '404':
   status_404 += 1
  elif status == '500':
   status_500 += 1
  elif status == '502':
   status_502 += 1
  elif status == '503':
   status_503 += 1
  elif status == '504':
   status_504 += 1
 log.close()
 #print "status_2xx: %s\nstatus_403: %s\nstatus_404: %s\nstatus_500: %s\nstatus_502: %s\nstatus_503: %s\nstatus_504: %s\nstatus_all: %s\nrt: %s\nbandwidth: %s\n" % (status_2xx/CRON_TIME,status_403/CRON_TIME,status_404/CRON_TIME,status_500/CRON_TIME,status_502/CRON_TIME,status_503/CRON_TIME,status_504/CRON_TIME,status_all/CRON_TIME,rt/status_all,bandwidth/CRON_TIME)

 write_status("status_2xx: %s\nstatus_403: %s\nstatus_404: %s\nstatus_500: %s\nstatus_502: %s\nstatus_503: %s\nstatus_504: %s\nstatus_all: %s\nrt: %s\nbandwidth: %s\n" % (status_2xx/CRON_TIME,status_403/CRON_TIME,status_404/CRON_TIME,status_500/CRON_TIME,status_502/CRON_TIME,status_503/CRON_TIME,status_504/CRON_TIME,status_all/CRON_TIME,rt/status_all,bandwidth/CRON_TIME))

if __name__ == '__main__':
 start_position,end_position = get_position()
 handle_log(start_position,end_position)

cat /tmp/http_status
status_2xx: 17.3333333333
status_403: 0.0
status_404: 1.0
status_500: 0.0
status_502: 0.0
status_503: 0.0
status_504: 0.0
status_all: 20.0
rt: 0.0782833333333
bandwidth: 204032.0

In [5]: '99772400' > '100227572'
Out[5]: True

In [6]: int('99772400') > int('100227572')
Out[6]: False

#日志轮转导致start_position > end_position
#print start_position,end_position
if int(start_position) > int(end_position):
 start_position = 0
#日志停止滚动时
elif int(start_position) == int(end_position):
 os._exit(1)