How to setup a QA server using Fedora 23 and tox

Tox is a tool which sits on top of virtualenv, the venerable Python environment manager. Tox uses virtualenv to test your code-base against multiple versions of Python. In this article, we will setup various Python installations and tox to run tests against Python versions 2.7, 3.5.

The first step is to install all the prerequisites for building Python ourselves because we would like to keep control of all the python installations. We can do so with the following commands:

$ sudo dnf groupinstall "Development tools"
$ sudo dnf install zlib-devel bzip2-devel openssl-devel ncurses-devel sqlite-devel readline-devel tk-devel gdbm-devel db4-devel libpcap-devel xz-devel

Next we need to download, extract, and compile our Python interpreters.

We can do that with the following commands:

cd /tmp

tar xvf Python-3.5.1.tgz
tar xvf Python-2.7.11.tgz

mkdir ~/python
cd Python-3.5.1 && ./configure --prefix ~/python/3.5 && make && make altinstall && cd ..
cd Python-2.7.11 && ./configure --prefix ~/python/2.7 && make && make altinstall && cd ..

So we will install tox into our 2.7 Python installation. This choice is completely arbitrary, but if I run into problems I will update.

$ ~/python/2.7/bin/python -m ensurepip
$ ~/python/2.7/bin/pip install tox

Now we will have the tox command available in ~/python/2.7/bin/tox. We could execute tox by issuing the command with the path, but tox would not be able to find the python executables. The solution to that is to add both Python's bin directories to your PATH. We can do that with the following command:

$ export PATH=~/python/2.7/bin:~/python/3.5/bin:$PATH

Now we can run tox and it will find both Python interpreters. If you would like to add these to your PATH permanently, you can add that above command to your ~/.bashrc.

So now we need to set up a project which uses tox to run its tests against multiple versions of Python. We will leave this for my next post in the interest of making short, sweet posts and to allow me to increase the rate at which I release my blog posts.

Remember to leave a comment below.

Have fun and Happy coding!

Written on March 30, 2016