Gunicorn service script {Start | Restart | Stop | Reload | Quit}

gunicorn_service.py

# python3 based gunicorn service
#!/usr/bin/env python3
#coding: utf-8

#####################################
# Sample Config file                #
# pidfile='config/gunicornRun.pid'; #
# app='server:app';                 #  
# bind='127.0.0.1:8000'             #
#####################################

import os
import imp
import time
import signal
import argparse
from subprocess import check_output, CalledProcessError
from subprocess import PIPE, STDOUT

# !!! You must specify this !!!
CONFIG_PATH = 'config/gunicorn_conf.py';

config = imp.load_source('config', CONFIG_PATH);

def getstatusoutput(cmd):
    try:
        data = check_output(cmd, shell=True, universal_newlines=True, stderr=STDOUT)
        status = 0
    except CalledProcessError as ex:
        data = ex.output
        status = ex.returncode
    if data[-1:] == '\n':
        data = data[:-1]
    return status, data

def get_pid():
    if os.path.exists(config.pidfile):
        with open(config.pidfile, 'r') as f:
            return int(f.read())
    else:
        print('[Error]: pid file not exists!');
        return None

def rm_pidfile():
    if os.path.exists(config.pidfile):
        print('[Remove File]: %s' % config.pidfile);
        os.remove(config.pidfile)


def status():
    if os.path.exists(config.pidfile):
        status, output = getstatusoutput('ls -l %s' % config.pidfile)
        print(output);
        print('[Pid File]: %s' % output);
        pid = get_pid()
        try:
            os.kill(pid, 0)
            print('[OK]: <pid: %d> is alive.' % pid);
        except OSError as e:
            print('[Error]: <pid: %d> has gone!' % pid);
            rm_pidfile()
    else:
        print('[Pid File]: NOT exists!');

    status_cmd = 'ps aux | grep [g]unicorn.*%s' % config.app
    print('[Process List]:  %s' % status_cmd);
    status, output = getstatusoutput(status_cmd)

    lines = [line for line in output.split('\n')]
    print('''--------------------------------------------------
%s
--------------------------------------------------''' % '\n'.join(lines));
    
def Quit():
    pid = get_pid()
    if pid:
        print('>>> Quiting ......');
        try:
            os.kill(pid, signal.SIGQUIT)
        except OSError as e:
            print('[Failed]: Server haven\'t start yet!');
        finally:
            time.sleep(1)
            rm_pidfile()


def Stop():
    pid = get_pid()
    if pid:
        print('>>> Stoping ......');
        try:
            os.kill(pid, signal.SIGTERM)
            print('[Success]: ok!');
        except OSError as e:
            print('[Failed]: <pid: %d> has gone!' % pid);
        finally:
            rm_pidfile()


def Reload():
    pid = get_pid()
    if pid:
        print('>>> Reloading ......');
        try:
            os.kill(pid, signal.SIGHUP)
        except OSError as e:
            print('[Failed]: Server haven\'t start yet!');


def start(bind):
    if os.path.exists(config.pidfile):
        pid = get_pid()
        print('<< Server already started! >>');
    else:
        print('>>> Starting server ......');
        if bind is None:
            bind = config.bind
        run_cmd = 'gunicorn --daemon -c %(config)s  -b %(bind)s  %(app)s ' % {
            'config' : CONFIG_PATH,
            'bind' : bind,
            'app': config.app,
        }
        print('[Run Command]: %s' % run_cmd);
        code, output = getstatusoutput(run_cmd)
        print(code);

        if code == 0:
            time.sleep(8)
            pid = get_pid()
            try:
                os.kill(pid, 0)
                print('''
[Success]:
===========
    pid      =  %d
    pidfile  =  %s
    address  =  %s
                ''' % (pid, config.pidfile, bind));
            except OSError as e:
                print('''
[Failed]:
========
    Process start failed.
    Permission denied? You may run this script as `root'.
                ''');
                rm_pidfile()
        else:
            print('[Failed]: status=[%d], output=[%s]' % (code, output));


def restart(bind):
    Quit()
    start(bind)

def main():
    parser = argparse.ArgumentParser(description='Manage the gunicorn(just like apache) server.')
    parser.add_argument('--start', action='store_true', help='Start your wsgi application. (config = %s, app = %s)' % (CONFIG_PATH, config.app))
    parser.add_argument('--quit', action='store_true', help='[Not Recommended!] Quick shutdown. ')
    parser.add_argument('--stop', action='store_true', help='Graceful shutdown. Waits for workers to finish their current requests up to the graceful timeout.')
    parser.add_argument('--reload', action='store_true', help='Reload the configuration, start the new worker processes with a new configuration and gracefully shutdown older workers.')
    parser.add_argument('--restart', action='store_true', help='[Not Recommended!] Simply `quit\' the server then `start\' it')
    parser.add_argument('--status', action='store_true', help='Show gunicorn processes.')
    parser.add_argument('-b', '--bind', metavar='ADDRESS', help='The socket to bind. [[\'127.0.0.1:8000\']]')
    args = parser.parse_args()

    # `start' and `restart' are special.
    if args.start:
        start(args.bind)
        return
    elif args.restart:
        restart(args.bind)
        return

    for label, func in {'status': status,
                        'quit': Quit,
                        'stop': Stop,
                        'reload': Reload }.items():
        if getattr(args, label):
            func()
            break
    else:
        parser.print_help()


if __name__ == '__main__':
    main()