python - Running Sudo Command with paramiko

Question

I am trying to execute a sudo command on a remote machine using python-paramiko, when I execute the command, I bind it with 3 streams, and I use the input stream to pass the password, but it doesn't work, this is the traceback result:

Traceback (most recent call last):
File "<input>", line 1, in <module>
File "/usr/local/lib/python2.7/dist-packages/paramiko/file.py", line 314, in write
self._write_all(data)
File "/usr/local/lib/python2.7/dist-packages/paramiko/file.py", line 439, in _write_all
count = self._write(data)
File "/usr/local/lib/python2.7/dist-packages/paramiko/channel.py", line 1263,in _write
self.channel.sendall(data)
File "/usr/local/lib/python2.7/dist-packages/paramiko/channel.py", line 796, in sendall
raise socket.error('Socket is closed')
error: Socket is closed

and this is my python code:

import paramiko
ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
ssh.connect('192.168.0.104', username='cdc',password='123456')
stdin, stdout, stderr = ssh.exec_command("sudo dmesg")
stdin.write("123456
")
stdin.flush()
print stdout.readlines()
ssh.close()

Any help? Thanks in advance

Answer 1

First of all, have you tried in console with ssh cdc@192.168.0.104 "sudo -S -p '' dmesg". If it also fails, then you might check the sshd settings and the sudoer settings.

If it works well, please add some echo between lines, so that we can know exactly when the exception was thrown. I highly doubt that you should change sudo dmesg to sudo -S -p '' dmesg.

You might also try my wrapper of paramiko. I can use it smoothly to access any CentOS/SuSE node and perform any commands (w/wo sudo privilege):

#!/usr/bin/python

from StringIO import StringIO
import paramiko 

class SshClient:
    "A wrapper of paramiko.SSHClient"
    TIMEOUT = 4

    def __init__(self, host, port, username, password, key=None, passphrase=None):
        self.username = username
        self.password = password
        self.client = paramiko.SSHClient()
        self.client.set_missing_host_key_policy(paramiko.AutoAddPolicy())
        if key is not None:
            key = paramiko.RSAKey.from_private_key(StringIO(key), password=passphrase)
        self.client.connect(host, port, username=username, password=password, pkey=key, timeout=self.TIMEOUT)

    def close(self):
        if self.client is not None:
            self.client.close()
            self.client = None

    def execute(self, command, sudo=False):
        feed_password = False
        if sudo and self.username != "root":
            command = "sudo -S -p '' %s" % command
            feed_password = self.password is not None and len(self.password) > 0
        stdin, stdout, stderr = self.client.exec_command(command)
        if feed_password:
            stdin.write(self.password + "
")
            stdin.flush()
        return {'out': stdout.readlines(), 
                'err': stderr.readlines(),
                'retval': stdout.channel.recv_exit_status()}

if __name__ == "__main__":
    client = SshClient(host='host', port=22, username='username', password='password') 
    try:
       ret = client.execute('dmesg', sudo=True)
       print "  ".join(ret["out"]), "  E ".join(ret["err"]), ret["retval"]
    finally:
      client.close()