django mysqldump management command

mysqldump.py

# -*- coding: utf-8 -*-
import os
import sys
from optparse import make_option

from django.core.management.base import BaseCommand
from django.core.management.base import CommandError
from django.db import connections
from django.db import DEFAULT_DB_ALIAS
from django.db.backends import BaseDatabaseClient


class MysqlDumpClient(BaseDatabaseClient):
    executable_name = 'mysqldump'

    def runshell(self):
        settings_dict = self.connection.settings_dict
        args = [self.executable_name]
        db = settings_dict['OPTIONS'].get('db', settings_dict['NAME'])
        user = settings_dict['OPTIONS'].get('user', settings_dict['USER'])
        passwd = settings_dict['OPTIONS'].get('passwd', settings_dict['PASSWORD'])
        host = settings_dict['OPTIONS'].get('host', settings_dict['HOST'])
        port = settings_dict['OPTIONS'].get('port', settings_dict['PORT'])
        defaults_file = settings_dict['OPTIONS'].get('read_default_file')
        # Seems to be no good way to set sql_mode with CLI.

        if defaults_file:
            args += ["--defaults-file=%s" % defaults_file]
        if user:
            args += ["--user=%s" % user]
        if passwd:
            args += ["--password=%s" % passwd]
        if host:
            if '/' in host:
                args += ["--socket=%s" % host]
            else:
                args += ["--host=%s" % host]
        if port:
            args += ["--port=%s" % port]
        if db:
            args += [db]

        if os.name == 'nt':
            sys.exit(os.system(" ".join(args)))
        else:
            os.execvp(self.executable_name, args)


class Command(BaseCommand):
    help = ("Runs the command-line client for specified database, or the "
            "default database if none is provided.")

    option_list = BaseCommand.option_list + (
        make_option('--database', action='store', dest='database',
                    default=DEFAULT_DB_ALIAS,
                    help='Nominates a database onto which to '
                         'open a shell.  Defaults to the "default" database.'),
    )

    requires_model_validation = False

    def handle(self, **options):
        connection = connections[options.get('database')]
        client = MysqlDumpClient(connection)
        try:
            client.runshell()
        except OSError:
            # Note that we're assuming OSError means that the client program
            # isn't installed. There's a possibility OSError would be raised
            # for some other reason, in which case this error message would be
            # inaccurate. Still, this message catches the common case.
            raise CommandError(
                'You appear not to have the %r program installed or on your '
                'path.' % client.executable_name)