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Using the python interactive shell and openssh running locally, I keep getting an "No existing session" exception using paramiko. My code is below.
import paramiko
ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
ssh.connect('localhost',username=name,password=pw)
Results in:
No handlers could be found for logger "paramiko.transport"
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/local/lib/python2.6/dist-packages/paramiko-1.7.7.1-py2.6.egg/paramiko/client.py", line 332, in connect
self._auth(username, password, pkey, key_filenames, allow_agent, look_for_keys)
File "/usr/local/lib/python2.6/dist-packages/paramiko-1.7.7.1-py2.6.egg/paramiko/client.py", line 493, in _auth
raise saved_exception
paramiko.SSHException: No existing session
I was able to connect previously, but had been trying to adjust this to allow for key based authorization. That failed, and since then I have not been able to connect locally. I have tried restarting openssh, and have connected to another server successfully. After searching through here, all I have found are mentions of authorization exceptions, which does not appear to be the case here.
363
Using exec_command() in Paramiko returns a tuple (stdin, stdout, stderr) . Most of the time, you just want to read stdout and ignore stdin and stderr . You can get the output the command by using stdout. read() (returns a string) or stdout.
An SSH Transport attaches to a stream (usually a socket), negotiates an encrypted session, authenticates, and then creates stream tunnels, called channels , across the session. Multiple channels can be multiplexed across a single session (and often are, in the case of port forwardings).
Paramiko helps you automate repetitive system administration tasks on remote servers. More advanced Paramiko programs send the lines of a script one at a time. It does this rather than transacting all of a command, such as df or last , synchronously to completion.
As you already have password you don't need to talk to agent or look for private keys stored on your machine. So try passing extra parameters allow_agent, look_for_keys:
ssh.connect('localhost',username=name,password=pw,allow_agent=False,look_for_keys=False)
I had a spare public key with a key pass phrase in my ssh-add list. Once I removed it, I was able to execute my paramiko based script properly.
To list:
ssh-add -l
To delete all:
ssh-add -D
To re-add:
ssh-add /FULL/PATH/TO/id_rsa
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