Power.py

#coding=utf8
import sys
import os
import time
import RPi.GPIO as GPIO
from fabric import SerialGroup as Group

GPIO.setmode(GPIO.BOARD)
GPIO.setup(40, GPIO.IN)

connect_kwargs = {
            'key_filename': '/home/pi/.ssh/id_rsa'
        }

class PowerState(object):
    def __init__(self):
        self.off_count = 0

    def update_count(self, state):
        if state:
            self.off_count = 0
        else:
            self.off_count += 1
        #print "state:", state, "count:", self.off_count
        if self.off_count > 60:
            self.power_off()

    def power_off(self):
        #print "off!"
        try:
             Group(
                '10.0.1.100',
                '10.0.1.101',
                '10.0.1.102',
                user="root",
                connect_kwargs=connect_kwargs
                ).run('halt -p')
        except:
            pass
        os.system('halt -p')

def check_pin():
    return GPIO.input(40)

def main():
    powerstate = PowerState()
    try:
        while True:
            powerstate.update_count(check_pin())
            time.sleep(1)
    except KeyboardInterrupt:
        GPIO.cleanup()
        sys.exit(1)

if __name__=="__main__":
    main()
    GPIO.cleanup()