Before reading this, please make sure you are familiar with concepts and ideas covered in the pt.1 of this post. This post will be short and will simply create an additional file that will help us out with deployment task automation. The code for this project will be available at this git repository make sure you checkout to git branch pt2! Also if you are not lazy 😉 I highly encourage you to do all the steps in this tutorial manually.

Create Fabric File

In this stage we will create a new fabfile.py. This file will contain all the useful devops functions we will write and define. Keep in mind that fabric2 as oppose to fabric is relatively very new and still under active development. The biggest benefit of the fabric2 is that it runs on python2.7 and python3.4+. This means you will not need to hack your system path variables (on your terminal) every time your project is written on python 3.4+, because fabric package installed using pip3 will simply crash.

cd <my-django-repo>
cd <cool_project>
source ../env/bin/activate
pip install fabric2

Now close and reopen new terminal window, because sometimes stubs installed via pip do not work. Stub for those who do not know is a python script that is not a library, stubs are used as standalone scripts, that help us out with various tasks. Stubs can be called from terminal directly as long as the stub directory is in your $PATH variable. Every python virtual environment will have its own stub directory in our case they are stored at ../env/bin/.

Since we closed the terminal we need to activate virtual env again!

cd <my-django-repo>
cd <cool_project>
source ../env/bin/activate

By now you should notice that the last line you have called calls a python stub called activate

Create Fabric Script

We need to create a new fabric.py file:

cd <my-django-repo>
cd <cool_project>
touch fabfile.py

now copy contents below to fabfile.py

import os
from invoke import task

# These constants are Hacky, but for now I do not know how to fix it using
# invoke, because invoke does not load exported variables of my terminal session
AC = 'export TERM=xterm-256color; source ../env/bin/activate'
ACA = AC + ' && '



@task
def penv(c):
    c.run(ACA + "/usr/bin/env", pty=True)


@task
def freeze(c):
    output = c.run(ACA + "pip freeze > requirements.txt")


@task
def shellbp(c):
    c.run(ACA + 'bpython -i manage.py shell', pty=True)


@task
def shell(c):
    c.run(ACA + 'manage.py shell', pty=True)


@task
def run(c):
    c.run(ACA + 'manage.py runserver', pty=True)


@task
def purge_cache(c):
    c.run(ACA + 'find . -d -name __pycache__ -exec rm -rf {} \;', pty=True)


@task
def test(c):
    c.run(ACA + 'manage.py test', pty=True)

Test The Fabric2

Using fabric2 CLI is relatively painless. You Can list all the available tasks by calling fab2 -l

let's list fab2 tasks:

fab2 -l

let's start our Django project using fab2:

fab2 run

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Outro

This was a brief tutorial it did not even scratch the surface of fabric2 I highly recommend you to check. The fabfile.py for yourself and try to understand what is written in that script. I want to warn you that I may update the fabfile.py snippet showed in this blogpost, but this will be only for the greater good, because I currently have not fiugred out a way of importing bash environment variables to Nagios (Nagios is the core lib of fabric2). Happy hacking and please do leave questions and suggestions in the comments.