【Python真的很强大】使用telnetlib编写nagios命令来监控远程主机cpu-load

      需求: 远程unix主机cpu load 有时过高,现在需要监控它,当超过阀值则email报警. 访问该主机只能通过telnet,不能安装其他任何library。

      现有资源: 已经有nagios环境，python已自带telnetlib模块，可以通过执行uptime命令获取1(5,10)分钟平均cpu load。

     

       通常,用shell script 编写nagios命令规范如下:

 

     

echo "OK status: ….”
     exit 0
echo "WARNING status: ….”
     exit 1
echo "CRITICAL status: ….”
     exit 2
echo "UNKNOWN status: ….”
     exit 3

 

 

   接口规范依赖exit code.

 

   完成后的python(2.7) 代码如下:

 

 

#!/usr/bin/python
# -*- coding: utf-8 -*-
import telnetlib
import sys,os
import datetime
import traceback
import logging
import logging.handlers
import getopt



def script_path():
    path = os.path.realpath(sys.argv[0])
    if os.path.isfile(path):
	path = os.path.dirname(path)
    return os.path.abspath(path)


LOGGING_MSG_FORMAT  = '[%(asctime)s] [%(levelname)s] [%(module)s] [%(funcName)s] [%(lineno)d] %(message)s'
LOGGING_DATE_FORMAT	= '%Y-%m-%d %H:%M:%S'

logging.basicConfig(level=logging.DEBUG,format=LOGGING_MSG_FORMAT,datefmt=LOGGING_DATE_FORMAT)
log = logging.getLogger('check_cpu_load_average_via_telnet')
if os.path.exists("/usr/local/nagios"):
    log_path = os.path.join("/usr/local/nagios",'logs')
else:
    log_path = os.path.join(script_path(),'logs')
if not os.path.exists(log_path):
    os.makedirs(log_path)
log_file = os.path.join(log_path,'check_cpu_load_average_via_telnet.log')
logger = logging.handlers.TimedRotatingFileHandler(log_file,'midnight',1)
logger.setFormatter(logging.Formatter(LOGGING_MSG_FORMAT))
log.addHandler(logger)


if __name__ == '__main__':
    try:
        reload(sys)
        sys.setdefaultencoding("utf-8")
	#accept -t via command check_nrpe
	opts, args = getopt.getopt(sys.argv[1:],"t:", ["host=","port=","user=","password=","cpuLoadLimit=","timeout="])
	host = None
	port = 23
	username = None
	password = None
	cpuLoadLimit = None
	login_Timeout = 30
	for a,o in opts:
	    if a in ('--host'):
		host=o
	    elif a in ('--port'):
		port=int(o)
	    elif a in ('--user'):
		username=o 
	    elif  a in ('--password'):
		password=o
	    elif a in ('--cpuLoadLimit'):
		cpuLoadLimit=float(o)
	    elif a in ('-t',"--timeout"):
		login_Timeout = round(float(o))
	    
        log.info("telnet %s:%s with user:%s, set cpu load limit=%s,timeout=%s", host,str(port),username,str(cpuLoadLimit),str(login_Timeout))
        CRLF = '\r\n'
        finish = 'telecom> '
	#finish = '$ '
        
        tn = telnetlib.Telnet(host=host,port=port, timeout=login_Timeout)
        
        #tn.set_debuglevel(2)
        tn.read_until('login: ',timeout=5)
        tn.write(username + CRLF)
        
        tn.read_until('Password: ',timeout=5)
        tn.write(password + CRLF)
        
        tn.read_until(finish,timeout=5)
        
        tn.write('uptime && sleep 1 '+CRLF)
        log.info("run command: uptime")
        
        tn.write("exit && sleep 1" + CRLF)
        log.info("run command: exit")
        
        resultOfCommands = tn.read_all()
        log.info("Result of Commands:%s",resultOfCommands)
	cpu_load_1_minute = resultOfCommands.split('load average:')[-1].strip().split(",")[0]
	try:
	    cpu_load_1_minute = float(cpu_load_1_minute)
	except:
	    print "exception occured while parsing the cpu_load_1_minute"
	    sys.exit(3) 
	    log.error(traceback.format_exc())
        tn.close()
	if cpu_load_1_minute < cpuLoadLimit:
	    print "[ok] cpu load = %s for %s" % (str(cpu_load_1_minute), host)
	    sys.exit(0)
	elif cpu_load_1_minute  == cpuLoadLimit:
	    print "[warn] cpu load approach to %s for %s" % (str(cpu_load_1_minute),  host)
	    sys.exit(1)
	else:
	    print "[Not ok] cpu load = %s[limit:%s] for %s" % (str(cpu_load_1_minute),str(cpuLoadLimit), host)
	    sys.exit(2)
    except SystemExit as e:
	sys.exit(e)
    except:
        errMsg = traceback.format_exc()
	print "exception occured, err msg:%s" % errMsg
	exit(3)
	
        

     备注: 防止check_nrpe命令timeout(默认10sec), 加了参数-t 30.