树莓派 CPU内存监视

前提

需要一个 http服务器提供访问，还需要一个 websocket吐服务器数据，至于怎么编译nginx这边就不讲了

预览

代码

这里主要给出后端python的代码，前端主要是用backbone + smoothiecharts实现

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

import tornado.web
import tornado.websocket
import tornado.ioloop
import subprocess, threading, json, re

def vmstat():
	memoryKey = ['swpd', 'free', 'buff', 'cache', 'total']
	cpuKey = ['us', 'sy', 'id', 'wa']
	space = re.compile('\s+')
	memTotal = subprocess.check_output("cat /proc/meminfo | grep MemTotal | sed 's/\\w*:\\s*\\([0-9]*\\).*/\\1/'", shell = True).strip()
	# print(memTotal)
	# 这个地方要使用 shell = True 的话，需要记得退出的时候关闭子进程
	p = subprocess.Popen(['vmstat', '1', '-n'], stdout = subprocess.PIPE)
	io_loop = tornado.ioloop.IOLoop.instance()
	p.stdout.readline()
	p.stdout.readline()
	for line in iter(p.stdout.readline, ''):
		# print(line)
		fields = space.split(line.strip())
		memoryVal = fields[2: 6]
		memoryVal.append(memTotal)
		result = dict(memory=dict(zip(memoryKey, memoryVal)), cpu=dict(zip(cpuKey, fields[12: 16])))
		result = json.dumps(result)
		print(result)
		for waiter in MonitorHandler.waiters:
			io_loop.add_callback(waiter.write_message, result)

class MonitorHandler(tornado.websocket.WebSocketHandler):
	waiters = set()
	def open(self):
		MonitorHandler.waiters.add(self)
		print('waiters: ', len(MonitorHandler.waiters))
	def on_message(self, message):
		pass

	def on_close(self):
		MonitorHandler.waiters.remove(self)
		print('waiters: ', len(MonitorHandler.waiters))

class Application(tornado.web.Application):
	def __init__(self):
		handlers = [
			('/', MonitorHandler)
		]
		super(Application, self).__init__(handlers)

def main():
	app = Application()
	app.listen(8888)
	t = threading.Thread(target=vmstat)
	t.daemon = True
	t.start()
	print('Starting the server...')
	tornado.ioloop.IOLoop.instance().start()


if __name__ == '__main__':
	main()