【Django】如何自定义manage.py命令？ 达到启动后台进程的目的？

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代码：

#-*- coding:utf-8 -*-
"""
The handle active user mail send
"""

from django.core.management.base import BaseCommand, CommandError
from django.db import models
#from placeholders import *
import os
import time
import logging

logger = logging.getLogger("file_protect.alarm_handler")
logger = logging.getLogger("file_protect.views")

class Command(BaseCommand):
def handle(self, *args, **options):
print ‘hello, django!‘
while(True):
logger.debug("hello, django")
time.sleep(5)

 

启动

####################系统软件安装-使用apt-get安装####################
apt-get update -qq -y
apt-get install libmysqlclient-dev python-dev -qq -y
apt-get install libmysqlclient-dev python-dev daemon -qq -y

#################启动日志处理Daemon#############################
if daemon -n alarm_handler_daemon --running; then
daemon -n alarm_handler_daemon --stop
fi

while daemon -n alarm_handler_daemon --running; do
sleep 1
done

daemon -n alarm_handler_daemon -r /opt/ENV/ubuntu1227/bin/python $API_PROJECT_DIR/manage.py alarm_handler
echo "alarm_handler_daemon is running"

 

 

我们都用过Django的django-admin.py和manage.py。django-admin.py是一个命令行工具，可以执行一些管理任务，比如创建Django项目。而manage.py是在创建每个Django project时自动添加在项目目录下的，只是对manage.py的一个简单包装，其功能是将Django project放到sys.path目录中，同时设置DJANGO_SETTINGS_MODULE环境变量为当前project的setting.py文件。

django-admin.py调用django.core.management来执行命令:

#!/usr/bin/env python
from django.core import management

if __name__ == "__main__":
management.execute_from_command_line()

excute_from_command_line()函数会根据命令行参数解析出命令的名称，根据命令名称调用相应的Command执行命令。Command位于各个管理模块的commands模块下面。

所谓管理模块，是指在app模块下的名字为management的模块。Django通过django.core.management.find_management_module函数发现"管理模块":

django.core.management.find_management_module()
def find_management_module(app_name):
"""
Determines the path to the management module for the given app_name,
without actually importing the application or the management module.

Raises ImportError if the management module cannot be found for any reason.
"""
parts = app_name.split(‘.‘)
parts.append(‘management‘)
parts.reverse()
part = parts.pop()
path = None

然后通过django.core.management.find_commands函数找到命令类。find_commands函数会在管理模块下查找.py文件，并将.py文件的名称匹配到命令名称:

def find_commands(management_dir):
"""
Given a path to a management directory, returns a list of all the command
names that are available.

Returns an empty list if no commands are defined.
"""
command_dir = os.path.join(management_dir, ‘commands‘)
try:
return [f[:-3] for f in os.listdir(command_dir)
if not f.startswith(‘_‘) and f.endswith(‘.py‘)]
except OSError:
return []

最后，通过django.core.management.load_command_class函数加载该.py文件中的Command类:

def load_command_class(app_name, name):
"""
Given a command name and an application name, returns the Command
class instance. All errors raised by the import process
(ImportError, AttributeError) are allowed to propagate.
"""
module = import_module(‘%s.management.commands.%s‘ % (app_name, name))
return module.Command()

在执行命令的时候，会执行相应Command类的handle方法。所有的Command类都应该是django.core.management.base.BaseCommand的直接或间接子类。

原理搞清楚了，扩展manage命令就很容易了。创建一个app并加入到settings的INSTALLED_APPS中，在该app下面创建management.commands模块，并创建hello.py文件:

from django.core.management.base import BaseCommand, CommandError
from django.db import models
#from placeholders import *
import os

class Command(BaseCommand):
def handle(self, *args, **options):
print ‘hello, django!‘

就可以使用hello命令了:

$ python manage.py hello

hello, django!

 

参考资料：

扩展：http://www.cnblogs.com/holbrook/archive/2012/03/09/2387679.html
https://www.v2ex.com/t/58381 http://janetriley.net/2014/11/quick-how-to-custom-django-management-commands.html http://www.cnblogs.com/linjiqin/p/3965046.html https://www.v2ex.com/t/58381 https://github.com/mitnk/tengtweets/blob/master/manage.py
 

【Django】如何自定义manage.py命令？ 达到启动后台进程的目的？