我需要在Python中使用端口轉發來通過SSH隧道與遠程MySQL數據庫進行通信。我下載了paramiko軟件包並嘗試了端口轉發演示(forward.py)。它的工作原理非常好,但是我無法將它集成到我自己的腳本中(類似於下面的腳本)。當主轉發函數被調用時,它進入一個無限循環,我的代碼的其餘部分不會執行。我如何使用forward.py演示並通過無限循環?如何在使用paramiko端口轉發演示時避免無限循環?
我的腳本:
import paramiko
import forward
import MySQLdb
import cfg
import sys
client = paramiko.SSHClient()
client.load_system_host_keys()
client.set_missing_host_key_policy(paramiko.WarningPolicy())
try:
client.connect(cfg.remhost, cfg.remport, username=cfg.user, password=cfg.password)
except Exception, e:
print '*** Failed to connect to %s:%d: %r' % (cfg.remhost, cfg.remport, e)
sys.exit(1)
try:
forward.forward_tunnel(3306, cfg.remhost, 3306, client.get_transport())
except KeyboardInterrupt:
print 'C-c: Port forwarding stopped.'
sys.exit(0)
try:
db = MySQLdb.connect('127.0.0.1', cfg.dbuser, cfg.dbpass, cfg.dbname)
except Exception, e:
print 'Failed to connect to database'
sys.exit(1)
try:
cursor = self.db.cursor(MySQLdb.cursors.DictCursor)
sql = 'SELECT * FROM ' + cfg.dbtable
cursor.execute(sql)
results = cursor.fetchall()
print str(len(results))
except Exception, e:
print 'Failed to query database'
sys.exit(1)
這裏是forward.py演示代碼的主要塊:
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
好的,因爲沒有人想回答這個問題,所以我的新問題是:我原來的問題是什麼讓別人失望?我應該改變什麼以便人們能夠真正迴應?我是否需要更改它或添加更多信息? – 2011-06-15 17:49:05