monit监控python脚本

使用monit监控Python脚本时，要注意：start中创建单独的进程，并运行到后台，否则monit会认为程序超时。
主要有两种方式：

1. 使用su命令

check process 1-wire with pidfile /tmp/1-wire.pid
   start = "/bin/su - username -c 'cd /home/username/Code/pi-fishtank-sensors; /usr/bin/python3 1-wire.py  >> /tmp/fishtank.log 2>&1 &'"
   stop = "/usr/bin/killall python3"

2. 把python启动命令封装到sh脚本中

check process scraper with pidfile /var/run/scraper.pid
   start = "/bin/scraper start"
   stop = "/bin/scraper stop"

scraper脚本内容

#!/bin/bash

PIDFILE=/var/run/scraper.pid

case $1 in
   start)
      echo $$ > ${PIDFILE};
      source /home
      exec python /home/scraper.py 2>/dev/null
   ;;
   stop)
      kill `cat ${PIDFILE}` ;;
   *)
      echo "usage: scraper {start|stop}" ;;
esac
exit 0