openssh-wrapper 0.4

OpenSSH python wrapper

Under some circumstances simple wrapper around OpenSSH ssh command-line utility seems more preferable than paramiko machinery.

This project proposes yet another hopefully thin wrapper around ssh to execute commands on remote servers. All you need thereis to make sure that OpenSSH client and Python interpreter are installed, and then install openssh-wrapper package.

Usage sample

Simple command execution

>>> from openssh_wrapper import SSHConnection
>>> conn = SSHConnection('localhost', login='root')
>>> ret = conn.run('whoami')
>>> print ret
command: whoami
stdout: root
stderr:
returncode: 0
>>> ret.command
'whoami'
>>> ret.stdout
'root'
>>> ret.stderr
''
>>> ret.returncode
0

If python interpreter is installed on a remote machine, you can also run pieces of python code remotely. The same is true for any other interpreter which can execute code from stdin

>>> ret = conn.run('whoami')
>>> print conn.run('print "Hello world"', interpreter='/usr/bin/python').stdout
Hello world

Yet another userful run method option is forward_ssh_agent (the feature which paramiko doesn’t yet have). Suppose you have access as support to foobar server while root@localhost does not, so you can take advantage of SSH agent forwarding

$ eval `ssh-agent`
Agent pid 5272
$ ssh-add
Identity added: /home/me/.ssh/id_rsa (/home/,e/.ssh/id_rsa)
$ python
>>> conn = SSHConnection('localhost', login='root')
>>> print conn.run('ssh support@foobar "whoami"', forward_ssh_agent=True).stdout
support

There is a sample which shows how to copy a file from local to remote machine. You can also define owner and mode of the target

>>> fd = open('test.txt', 'w')
>>> fd.write('Hello world')
>>> fd.close()
>>> from openssh_wrapper import SSHConnection
>>> conn = SSHConnection('localhost', login='root')
>>> conn.scp(('test.txt', ), target='/tmp', mode='0666', owner='nobody:')
>>> print conn.run('cat /tmp/test.txt').stdout
Hello world
>>> print conn.run('ls -l  /tmp/test.txt').stdout
-rw-rw-rw- 1 nobody nogroup ... /tmp/test.txt

You can also pass file-like objects instead of filenames to scp method. Behind the scenes the method creates temporary files for you, send them to remote target and then removes everything which has been created:

>>> from StringIO import StringIO
>>> data = StringIO('test')
>>> from openssh_wrapper import SSHConnection
>>> conn = SSHConnection('localhost', login='root')
>>> conn.scp((data, ), target='/tmp/test.txt', mode='0644')
>>> print open('/tmp/test.txt').read()
test