Fabric
About Fabric
Fabric is a Python (2.5 or higher) 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')
Once a task is defined, it may be run 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 ssh library (which Fabric itself uses.)
What is Fabric?
Fabric is a Python (2.5 or higher) library and command-line tool for streamlining the use of SSH for application deployment or systems administration tasks.
More specifically, Fabric is:
- A tool that lets you execute arbitrary Python functions via the command line;
- A library of subroutines (built on top of a lower-level library) to make executing shell commands over SSH easy and Pythonic.
Naturally, most users combine these two things, using Fabric to write and execute Python functions, or tasks, to automate interactions with remote servers. Let’s take a look.