#!/usr/bin/env python
# coding=utf-8
import os
import sched
import smtplib
import sys
import time
from email.header import Header
from email.mime.text import MIMEText

import psutil

from Daemon import Daemon

MEM_WARN_LINE = 85
CPU_WARN_LINE = 90
SCHED_TIME = 60*60*6  # 单位，秒
def sendmail(content):
    subject = '[Python服务器监控]%s服务器监控预警' % '192.168.8.122'
    username = 'username'
    password = 'password'
    smtp_server = 'smtp.126.com'
    header = '您好！<br/> %s服务器性能预警<br/>' % '192.168.8.122'
    footer = '--------------------------------------------------------<br/>此为系统邮件请勿回复'
    content = '%s<br/>%s<br/>%s' % (header, content, footer)

    msg = MIMEText(content, 'html', 'utf-8')  # 中文需参数‘utf-8'，单字节字符不需要
    msg['Subject'] = Header(subject, 'utf-8')
    msg['From'] = "%s<[email protected]>" % Header('Python监控预警','utf-8')

    msg['to'] = '[email protected]'  # 单独收信人
    msg_to_list = ["[email protected]", "[email protected]"]  # 多个收信人

    smtp = smtplib.SMTP()
    smtp.connect(smtp_server)
    smtp.login(username, password)
    smtp.sendmail(msg['From'], msg_to_list, msg.as_string())
    smtp.quit()


def is_mem_warning():
    mem = psutil.virtual_memory()
    if mem.percent > MEM_WARN_LINE:
        return [True, mem]
    else:
        return [False]


def is_cpu_warning():
    cpupercent = psutil.cpu_percent()
    if cpupercent > CPU_WARN_LINE:
        return [True, cpupercent]
    else:
        return [False]


def check_status():
    memwarn = is_mem_warning()
    is_send_mail = False

    if memwarn[0]:
        mem = memwarn[1]
        title = "内存预警[时间：%s]" % time.ctime()
        memmsg = str("%s\n 占用率：%s%%\n 总数：%s\n 已使用：%s\n 空闲：%s\n" % (title, mem.percent, mem.total, mem.used, mem.free))
        is_send_mail = True
    else:
        memmsg = ''

    cpuwarn = is_cpu_warning()

    if cpuwarn[0]:
        title = "CPU预警[时间：%s]" % time.ctime()
        cpumsg = str("%s\n 使用率 %s%%\n" % (title, cpuwarn[1]))
        is_send_mail = True
    else:
        cpumsg = ''

    if is_send_mail:
        sendmail("%s\n%s" % (memmsg, cpumsg))
        sys.stderr.write("[error]{%s} 监测异常\n %s\n%s" % (time.ctime(), memmsg, cpumsg))
        sys.stderr.flush()
    else:
        sys.stderr.write("[info]{%s} 监测无异常\n" % time.ctime())
        sys.stderr.flush()

    schedule.enter(SCHED_TIME, 0, check_status, ())


class MyTestDaemon(Daemon):
    def run(self):
        sys.stdout.write('[info]{%s} Daemon started with pid {%s}\n' % (time.ctime(), os.getpid()))
        sys.stdout.flush()
        # while True:
        schedule.enter(SCHED_TIME, 0, check_status, ())
        schedule.run()


if __name__ == '__main__':
    schedule = sched.scheduler(time.time, time.sleep)
    PIDFILE = '/tmp/daemon-sysinfo.pid'
    LOG = '/tmp/daemon-sysinfo.log'
    daemon = MyTestDaemon(pidfile=PIDFILE, stdout=LOG, stderr=LOG)

    if len(sys.argv) != 2:
        print('Usage: {} [start|stop]'.format(sys.argv[0]))
        raise SystemExit(1)

    if 'start' == sys.argv[1]:
        daemon.start()
    elif 'stop' == sys.argv[1]:
        daemon.stop()
    elif 'restart' == sys.argv[1]:
        daemon.restart()
    else:
        print('Unknown command {!r}'.format(sys.argv[1]))
        raise SystemExit(1)

#!/usr/bin/env python

import atexit
import os
import sys
import time
from signal import SIGTERM


class Daemon:
    """
    A generic daemon class.

    Usage: subclass the Daemon class and override the run() method
    """

    def __init__(self, pidfile, stdin='/dev/null', stdout='/dev/null', stderr='/dev/null'):
        self.stdin = stdin
        self.stdout = stdout
        self.stderr = stderr
        self.pidfile = pidfile

    def daemonize(self):
        """
        do the UNIX double-fork magic, see Stevens' "Advanced
        Programming in the UNIX Environment" for details (ISBN 0201563177)
        http://www.erlenstar.demon.co.uk/unix/faq_2.html#SEC16
        """
        try:
            pid = os.fork()
            if pid > 0:
                # exit first parent
                sys.exit(0)
        except OSError, e:
            sys.stderr.write("fork #1 failed: %d (%s)\n" % (e.errno, e.strerror))
            sys.exit(1)

        # decouple from parent environment
        os.chdir("/")
        os.setsid()
        os.umask(0)

        # do second fork
        try:
            pid = os.fork()
            if pid > 0:
                # exit from second parent
                sys.exit(0)
        except OSError, e:
            sys.stderr.write("fork #2 failed: %d (%s)\n" % (e.errno, e.strerror))
            sys.exit(1)

        # redirect standard file descriptors
        sys.stdout.flush()
        sys.stderr.flush()
        si = file(self.stdin, 'r')
        so = file(self.stdout, 'a+')
        se = file(self.stderr, 'a+', 0)
        os.dup2(si.fileno(), sys.stdin.fileno())
        os.dup2(so.fileno(), sys.stdout.fileno())
        os.dup2(se.fileno(), sys.stderr.fileno())

        # write pidfile
        atexit.register(self.delpid)
        pid = str(os.getpid())
        file(self.pidfile, 'w+').write("%s\n" % pid)

    def delpid(self):
        os.remove(self.pidfile)

    def start(self):
        """
        Start the daemon
        """
        # Check for a pidfile to see if the daemon already runs
        try:
            pf = file(self.pidfile, 'r')
            pid = int(pf.read().strip())
            pf.close()
        except IOError:
            pid = None

        if pid:
            message = "pidfile %s already exist. Daemon already running?\n"
            sys.stderr.write(message % self.pidfile)
            sys.exit(1)

        # Start the daemon
        self.daemonize()
        self.run()

    def stop(self):
        """
        Stop the daemon
        """
        # Get the pid from the pidfile
        try:
            pf = file(self.pidfile, 'r')
            pid = int(pf.read().strip())
            pf.close()
        except IOError:
            pid = None

        if not pid:
            message = "pidfile %s does not exist. Daemon not running?\n"
            sys.stderr.write(message % self.pidfile)
            return  # not an error in a restart

        # Try killing the daemon process
        try:
            while 1:
                os.kill(pid, SIGTERM)
                time.sleep(0.1)
        except OSError, err:
            err = str(err)
            if err.find("No such process") > 0:
                if os.path.exists(self.pidfile):
                    os.remove(self.pidfile)
            else:
                print str(err)
                sys.exit(1)

    def restart(self):
        """
        Restart the daemon
        """
        self.stop()
        self.start()

    def run(self):
        """
        You should override this method when you subclass Daemon. It will be called after the process has been
        daemonized by start() or restart().
        """

参考资料：

http://www.jianshu.com/p/e3f3d49093ca

http://blog.csdn.net/zm2714/article/details/8134118