在 python 中通过 SSH 运行远程 mysqldump

Question

您好，我正在尝试编写 Python 脚本以通过 SSH 连接到远程服务器并执行 mysqldump。到目前为止，我的方法是建立端口转发，然后运行我已经编写的备份脚本。我怀疑问题出在端口转发中，因为备份脚本非常简单。这是端口转发：

import getpass
import os
import socket
import select
import SocketServer
import sys

import paramiko

username = 'myusername'
remote_server = 'remote.servername'
remote_port = 3306
local_server = '127.0.0.1'
local_port = 3307
SSH_PORT = 22
password = None
keyfile = 'hosting.pem'

g_verbose = True


class ForwardServer (SocketServer.ThreadingTCPServer):
    daemon_threads = True
    allow_reuse_address = True


class Handler (SocketServer.BaseRequestHandler):

    def handle(self):
        try:
            chan = self.ssh_transport.open_channel('direct-tcpip',
                                                   (self.chain_host, self.chain_port),
                                                   self.request.getpeername())
        except Exception, e:
            verbose('Incoming request to %s:%d failed: %s' % (self.chain_host,
                                                              self.chain_port,
                                                              repr(e)))
            return
        if chan is None:
            verbose('Incoming request to %s:%d was rejected by the SSH server.' %
                    (self.chain_host, self.chain_port))
            return

        verbose('Connected!  Tunnel open %r -> %r -> %r' % (self.request.getpeername(),
                                                            chan.getpeername(), (self.chain_host, self.chain_port)))
        while True:
            r, w, x = select.select([self.request, chan], [], [])
            if self.request in r:
                data = self.request.recv(1024)
                if len(data) == 0:
                    break
                chan.send(data)
            if chan in r:
                data = chan.recv(1024)
                if len(data) == 0:
                    break
                self.request.send(data)
        chan.close()
        self.request.close()
        verbose('Tunnel closed from %r' % (self.request.getpeername(),))


def forward_tunnel(local_port, remote_host, remote_port, transport):
    # this is a little convoluted, but lets me configure things for the Handler
    # object.  (SocketServer doesn't give Handlers any way to access the outer
    # server normally.)
    class SubHander (Handler):
        chain_host = remote_host
        chain_port = remote_port
        ssh_transport = transport
    ForwardServer(('', local_port), SubHander).serve_forever()


def verbose(s):
    if g_verbose:
        print s



def pforward():
    paramiko.util.log_to_file('demo.log')
    client = paramiko.SSHClient()
    client.load_system_host_keys()
    client.set_missing_host_key_policy(paramiko.WarningPolicy())

    try:
        client.connect(remote_server, SSH_PORT, username, key_filename=keyfile,
                       look_for_keys=True)
    except Exception, e:
        print '*** Failed to connect to %s:%d: %r' % (remote_server, SSH_PORT, e)
        sys.exit(1)

    verbose('Now forwarding port %d to %s:%d ...' % (local_port, remote_server, remote_port))

    try:
        forward_tunnel(local_port, remote_server, remote_port, client.get_transport())
    except KeyboardInterrupt:
        print 'C-c: Port forwarding stopped.'
        sys.exit(0)
pforward()

一旦运行，这就是我的 mysql 备份脚本：

import MySQLdb
import os


conn = MySQLdb.connect (
    host = "127.0.0.1",
    user = "root",
    passwd = "password"
    port = 3307)

cursor = conn.cursor()

cursor.execute("SHOW DATABASES")

results = cursor.fetchall()
cursor.close()
conn.close()
print results
for result in results:
    backupfile=result[0]+".sql.gz"
    cmd="echo 'Back up "+result[0]+" database to yourLocation/"+backupfile+"'"
    os.system(cmd)
    cmd="mysqldump -u "+user+" -h "+host+" -p"+passwd+" --opt --routines --flush-privileges --single-transaction --database "+result[0]+" | gzip -9 --rsyncable > yourlocation/"+backupfile

这是我得到的错误：

_mysql_exceptions.OperationalError: (2013, "Lost connection to MySQL server at 'waiting for initial communication packet', 系统错误: 0")

Answer 1

好吧-所以我想我想多了，不需要设置端口转发和所有这些混乱。这是解决方案>

# -*- coding: utf-8 -*- # <nbformat>3.0</nbformat>

import paramiko
import os


savefile = 'dump.sql'
mykey = paramiko.RSAKey.from_private_key_file("/users/me/my-host.pem")

client = paramiko.SSHClient()
client.load_system_host_keys()
client.connect('hungry.turtles.com', username = "turtles", pkey = mykey)


def ssh(cmd):
    out = []
    msg = [stdin, stdout, stderr] = client.exec_command(cmd)
    for item in msg:
        try:
            for line in item:
                out.append(line.strip('\n'))
        except: pass

    return(list(out))

dump = ssh('mysqldump -u root -ppassword turtleturds')

file = open(savefile, 'w')
file.write(str(dump))
file.close()
print 'The dump had '+ str(len(dump))+ ' lines and was saved to '+ str(os.path.realpath('dump.sql'))