Ansible push daemon

ansible-push

#!/usr/bin/env python

import time, yaml, sys, os, atexit, signal, subprocess


class Daemon(object):
    def __init__(self, pidfile, stdin=os.devnull,
                 stdout=os.devnull, stderr=os.devnull,
                 home_dir='.', umask=022, verbose=1):
        self.stdin = stdin
        self.stdout = stdout
        self.stderr = stderr
        self.pidfile = pidfile
        self.home_dir = home_dir
        self.verbose = verbose
        self.umask = umask
        self.daemon_alive = True

    def daemonize(self):
        try:
            pid = os.fork()
            if pid > 0:
                sys.exit(0)
        except OSError, e:
            sys.stderr.write(
                "fork #1 failed: %d (%s)\n" % (e.errno, e.strerror))
            sys.exit(1)

        os.chdir(self.home_dir)
        os.setsid()
        os.umask(self.umask)

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

        if sys.platform != 'darwin':
            sys.stdout.flush()
            sys.stderr.flush()
            si = file(self.stdin, 'r')
            so = file(self.stdout, 'a+')
            if self.stderr:
                se = file(self.stderr, 'a+', 0)
            else:
                se = so
            os.dup2(si.fileno(), sys.stdin.fileno())
            os.dup2(so.fileno(), sys.stdout.fileno())
            os.dup2(se.fileno(), sys.stderr.fileno())

        def sigtermhandler(signum, frame):
            self.daemon_alive = False
            signal.signal(signal.SIGTERM, sigtermhandler)
            signal.signal(signal.SIGINT, sigtermhandler)

        if self.verbose >= 1:
            print "Started"

        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, *args, **kwargs):

        if self.verbose >= 1:
            print "Starting..."
        try:
            pf = file(self.pidfile, 'r')
            pid = int(pf.read().strip())
            pf.close()
        except IOError:
            pid = None
        except SystemExit:
            pid = None

        if pid:
            message = "pidfile %s already exists. Is it already running?\n"
            sys.stderr.write(message % self.pidfile)
            sys.exit(1)
        self.daemonize()
        self.run(*args, **kwargs)

    def stop(self):

        if self.verbose >= 1:
            print "Stopping..."

        pid = self.get_pid()

        if not pid:
            message = "pidfile %s does not exist. Not running?\n"
            sys.stderr.write(message % self.pidfile)

            if os.path.exists(self.pidfile):
                os.remove(self.pidfile)

            return

        try:
            i = 0
            while 1:
                os.kill(pid, signal.SIGTERM)
                time.sleep(0.1)
                i = i + 1
                if i % 10 == 0:
                    os.kill(pid, signal.SIGHUP)
        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)

        if self.verbose >= 1:
            print "Stopped"

    def restart(self):
        self.stop()
        self.start()

    def get_pid(self):
        try:
            pf = file(self.pidfile, 'r')
            pid = int(pf.read().strip())
            pf.close()
        except IOError:
            pid = None
        except SystemExit:
            pid = None
        return pid

    def is_running(self):
        pid = self.get_pid()

        if pid == None:
            print 'Process is stopped'
        elif os.path.exists('/proc/%d' % pid):
            print 'Process (pid %d) is running...' % pid
        else:
            print 'Process (pid %d) is killed' % pid

        return pid and os.path.exists('/proc/%d' % pid)

    def run(self):
        raise NotImplementedError


class AnsiblePush(Daemon):
    def run(self):
        while True:
            with open('/etc/ansible/andible-daemon.yml') as command_file:
                commands = yaml.load(command_file.read())

            for command in commands:
                subprocess.call('ansible-playbook ' + command, shell=True)

            time.sleep(900)


ansible_push = AnsiblePush('/tmp/ansible-push.pid')

if sys.argv[1] == 'start':
    ansible_push.start()

if sys.argv[1] == 'stop':
    ansible_push.stop()

if sys.argv[1] == 'restart':
    ansible_push.restart()

if sys.argv[1] == 'run':
    ansible_push.run()