Do I need to use virtualenv with Vagrant?

Question

I was used VirtualBox manual setups with virtualenvs inside them to run Django projects on my local machine. Recently I discovered Vagrant and decided to switch to it, because it seems very easy and useful.
But I can not figure - do I need still use virtualenv Vagrant VM, is it encouraged practice or forbidden?

Answer 1

If you run one vagrant VM per project, then there is no direct reason to use virtualenv.

If other contributors do not use vagrant, but do use virtualenv, then you might want to use it and support it to make their lives easier.

Answer 2

Virtualenv and other forms of isolation (Docker, dedicated VM, ...) are not necessarily mutually exclusive. Using virtualenv is still a good idea, even in an isolated environment, to shield the virtual system Python from your project packages. *nix systems use plethora of Python based utilities dependent on specific versions of packages being available in system Python and you don't want to mess with these.

Mind that virtualenv can still only go as far as pure Python packages and doesn't solve the situation with native extensions that will still mix with the system.

Answer 3

As Devin stated, it is not necessary to use virtualenv when you deploy to a vagrant machine as long as you are the sole user of the machine. However, I would still enable the use of a virtualenv, setup.py, etc. even if you do not use it for development or deployment.

In my (not so) humble opinion, any Python project should:

1. Include a .cvsignore, .gitignore, .hgignore, ... file that ignores the common Python intermediate files as well as virtualenv directories.
2. A requirements.txt file that lists the required packages in a pip-compliant format

3. Include a Makefile with the following targets:

   • environment: create the virtual environment using virtualenv or pyvenv
   • requirements: install required packages using pip and the requirements.txt file
   • develop: run setup.py develop using the virtual environment
   • test: run setup.py test
   • clean: remove intermediate files, coverage reports, etc.
   • maintainer-clean: remove the virtual environment

   The idea is to keep the Makefile as simple as possible. The dependencies should be set up so that you can clone the repository (or extract the source tarball) and run make test. It should create a virtual environment, install the requirements, and run the unit tests.

You can also include a Vagrantfile and a vagrant target in the Makefile that runs vagrant up. Add a vagrant destroy to the maintainer-clean target while you are at it.

This makes your project usable by anyone that is using vagrant or developing without it. If (when) you need to use deploy alongside another project in a vagrant or physical environment, including a clean setup.py and a Vagrantfile that describes your minimal environment makes it simple to install into a virtual environment or a shared vagrant machine.