2014-03-19 36 views
2

我试图通过ssh执行一些命令。当强制命令打开时,paramiko不起作用

import paramiko 
client = paramiko.SSHClient() 
client.set_missing_host_key_policy(paramiko.AutoAddPolicy()) 
private_key = paramiko.RSAKey.from_private_key_file("/home/kalombo/identity") 
client.connect(hostname=host, username=username, pkey=private_key) 
stdin, stdout, stderr = client.exec_command('pwd', timeout=5) 
for line in stdout: 
    print '... ' + line.strip('\n') 
client.close() 

如果ssh服务器有一个强制命令选项,那么当超时过期时,脚本停止并且什么也不做。有一个调试日志。你可以注意到“Force command”行:

DEBUG:paramiko.transport:starting thread (client mode): 0xb6d1bb4cL 
INFO:paramiko.transport:Connected (version 2.0, client OpenSSH_6.0p1) 
DEBUG:paramiko.transport:kex algos:[u'ecdh-sha2-nistp256', u'ecdh-sha2-nistp384', u'ecdh-sha2-nistp521', u'diffie-hellman-group-exchange-sha256', u'diffie-hellman-group-exchange-sha1', u'diffie-hellman-group14-sha1', u'diffie-hellman-group1-sha1'] server key:[u'ssh-rsa', u'ssh-dss', u'ecdsa-sha2-nistp256'] client encrypt:[u'aes128-ctr', u'aes192-ctr', u'aes256-ctr', u'arcfour256', u'arcfour128', u'aes128-cbc', u'3des-cbc', u'blowfish-cbc', u'cast128-cbc', u'aes192-cbc', u'aes256-cbc', u'arcfour', u'[email protected]'] server encrypt:[u'aes128-ctr', u'aes192-ctr', u'aes256-ctr', u'arcfour256', u'arcfour128', u'aes128-cbc', u'3des-cbc', u'blowfish-cbc', u'cast128-cbc', u'aes192-cbc', u'aes256-cbc', u'arcfour', u'[email protected]'] client mac:[u'hmac-md5', u'hmac-sha1', u'[email protected]', u'hmac-sha2-256', u'hmac-sha2-256-96', u'hmac-sha2-512', u'hmac-sha2-512-96', u'hmac-ripemd160', u'[email protected]', u'hmac-sha1-96', u'hmac-md5-96'] server mac:[u'hmac-md5', u'hmac-sha1', u'[email protected]', u'hmac-sha2-256', u'hmac-sha2-256-96', u'hmac-sha2-512', u'hmac-sha2-512-96', u'hmac-ripemd160', u'[email protected]', u'hmac-sha1-96', u'hmac-md5-96'] client compress:[u'none', u'[email protected]'] server compress:[u'none', u'[email protected]'] client lang:[u''] server lang:[u''] kex follows?False 
DEBUG:paramiko.transport:Ciphers agreed: local=aes128-ctr, remote=aes128-ctr 
DEBUG:paramiko.transport:using kex diffie-hellman-group1-sha1; server key type ssh-rsa; cipher: local aes128-ctr, remote aes128-ctr; mac: local hmac-sha1, remote hmac-sha1; compression: local none, remote none 
DEBUG:paramiko.transport:Switch to new keys ... 
DEBUG:paramiko.transport:Adding ssh-rsa host key for 8.8.8.8: 54c2349797979732dda94989530c1f4 
DEBUG:paramiko.transport:Trying SSH key 7d834324323429b09824eb 
DEBUG:paramiko.transport:userauth is OK 
INFO:paramiko.transport:Authentication (publickey) successful! 
DEBUG:paramiko.transport:Debug msg: Forced command. 
DEBUG:paramiko.transport:Debug msg: Port forwarding disabled. 
DEBUG:paramiko.transport:Debug msg: X11 forwarding disabled. 
DEBUG:paramiko.transport:Debug msg: Agent forwarding disabled. 
DEBUG:paramiko.transport:Debug msg: Pty allocation disabled. 
DEBUG:paramiko.transport:[chan 1] Max packet in: 34816 bytes 
DEBUG:paramiko.transport:[chan 1] Max packet out: 32768 bytes 
INFO:paramiko.transport:Secsh channel 1 opened. 
DEBUG:paramiko.transport:[chan 1] Sesch channel 1 request ok 

如果我禁用该选项一切正常。为什么会发生?我该如何解决它?

+0

正在执行的代替pwd的命令是什么?也许执行时间太长。 – ScoPi

回答

0
DEBUG:paramiko.transport:Debug msg: Forced command. 

有没有办法解决这个问题。如果服务器配置了强制的密钥命令,则使用该密钥打开的任何会话都将导致服务器忽略您请求的命令并调用强制命令。

不知道服务器运行的是什么命令,没有办法知道它为什么挂起。强制命令可能正在等待来自远程SSH客户端的输入,在这种情况下,它将无限期地等待。

强制命令可以通过环境变量“SSH_ORIGINAL_COMMAND”访问客户端请求的原始命令。强制命令可以检查此变量并调用客户端请求的命令,但强制命令必须记住此功能。