Fabric is a Python (2.5-2.7) library and command-line tool for streamlining the use of SSH for application deployment or systems administration tasks.

It provides a basic suite of operations for executing local or remote shell commands (normally or via sudo) and uploading/downloading files, as well as auxiliary functionality such as prompting the running user for input, or aborting execution.

Typical use involves creating a Python module containing one or more functions, then executing them via the fab command-line tool. Below is a small but complete "fabfile" containing a single task:

from fabric.api import run

def host_type():
    run('uname -s')

If you save the above as fabfile.py (the default module that fab loads), you can run the tasks defined in it on one or more servers, like so:

$ fab -H localhost,linuxbox host_type
[localhost] run: uname -s
[localhost] out: Darwin
[linuxbox] run: uname -s
[linuxbox] out: Linux

Done.
Disconnecting from localhost... done.
Disconnecting from linuxbox... done.

In addition to use via the fab tool, Fabric's components may be imported into other Python code, providing a Pythonic interface to the SSH protocol suite at a higher level than that provided by e.g. the Paramiko library (which Fabric itself uses.)