Fabric is a command-line tool for application deployment and systems administration tasks. It allows the user to run commands across a server farm.

This is intended to be setup and run on your local workstation/laptop.

To install the dependencies:

$ pip install -Ur requirements.txt

NB: if you get a "pip: command not found" error, run this first:

$ sudo easy_install pip

Configure it (see the fabric documentation for more examples),

$ echo 'user = jimbob' >> ~/.fabricrc

You can view a list of the available tasks:

$ fab -l

And execute against an environment and set of hosts like so:

$ fab preview all hosts
...
$ fab preview class:frontend do:'uname -a'
...

It was previously possible to use these scripts from the jumpboxes via the govuk_fab wrapper. This is no longer supported as it relied on SSH agent forwarding, which is a Bad Thing because other people with root access to that jumpbox would be able to re-use any of the private keys in your agent.

You should convert to the [local usage](#Local usage) method described above and ensure that you do not have the following option anywhere in your ~/.ssh/config:

ForwardAgent yes