不写代码，使用twistd实现ftp服务器

使用方法如下：

twistd ftp

这时启动的ftp服务器的HOME目录为/usr/local/ftp，匿名用户名为anonymous，密码为随便的一个邮箱地址，端口号为2121。

可以通过如下命令查看此服务器的其他参数：

twistd ftp –help

比较有用的就是–root，来指定登陆的根目录。还有就是–port指定端口号。

不过要注意的是，这个服务器仅用于调试，不要应用于产品环境，因为它并没有做安全性方面的工作。

#!/usr/bin/env python
# -*- coding: utf-8 -*-

"""a very simple ftp server by twisted
"""

import sys, os
sys.path.append('../../..')
os.environ['DJANGO_SETTINGS_MODULE'] = 'settings'

from twisted.protocols import ftp
from twisted.cred import portal, checkers, credentials, error as credError
from twisted.internet import reactor, defer
from zope.interface import implements
from twisted.python import filepath
from django.contrib.auth import authenticate
from django.contrib.auth.models import User

class UserChecker:
    implements(checkers.ICredentialsChecker)
    credentialInterfaces = (credentials.IUsernamePassword,)
    
    def __init__(self):
        "passwords: a dict-like object mapping usernames to passwords"

    def requestAvatarId(self, credentials):
        user = authenticate(username=credentials.username, password=credentials.password)
        if user is not None:
            if user.is_active:
                return defer.succeed(credentials.username)
            else:
                return defer.fail(credError.UnauthorizedLogin("access denied"))
        else:
            return defer.fail(credError.UnauthorizedLogin("No such user"))


class MyFTPRealm:
    implements(portal.IRealm)
    
    def __init__(self, anonymousRoot):
        self.anonymousRoot = filepath.FilePath(anonymousRoot)
    
    def requestAvatar(self, avatarId, mind, *interfaces):
        for iface in interfaces:
            if iface is ftp.IFTPShell:
                if avatarId is checkers.ANONYMOUS:
                    avatar = ftp.FTPAnonymousShell(self.anonymousRoot)
                else:
                    try:
                        user = User.objects.get(username=avatarId)
                        ftpdir = user.ftp.all()[0].ftpdir
                    except:
                        raise "没有该用户"
                    avatar = ftp.FTPShell(filepath.FilePath(ftpdir.encode("utf-8")))
                return ftp.IFTPShell, avatar, getattr(avatar, "logout", lambda:None)
        raise NotImplementedError("only IFTPShell interface is supported by this realm")


class MyFtpServer(ftp.FTP):
    def __init__(self, *args, **kw):
        super(ftp.FTP, self).__init__(*args, **kw)


    def dataReceived(self, data):
        self.transport.write(data)


if __name__ == "__main__":
    p = portal.Portal(MyFTPRealm(""))
    p.registerChecker(UserChecker())


    factory = ftp.FTPFactory(MyFtpServer())
    factory.portal = p
    reactor.listenTCP(2121, factory)
    reactor.run()