Creating a Development Environment¶

Python¶

As the OpenStack SDK is developed in Python, you will need at least one version of Python installed. It is strongly preferred that you have at least one of version 2 and one of version 3 so that your tests are run against both. Our continuous integration system runs against several versions, so ultimately we will have the proper test coverage, but having multiple versions locally results in less time spent in code review when changes unexpectedly break other versions.

Python can be downloaded from https://www.python.org/downloads.

virtualenv¶

In order to isolate our development environment from the system-based Python installation, we use virtualenv. This allows us to install all of our necessary dependencies without interfering with anything else, and preventing others from interfering with us. Virtualenv must be installed on your system in order to use it, and it can be had from PyPI, via pip, as follows. Note that you may need to run this as an administrator in some situations.:

$ apt-get install python-virtualenv  # Debian based platforms
$ yum install python-virtualenv      # Red Hat based platforms
$ pip install virtualenv             # Mac OS X and other platforms

You can create a virtualenv in any location. A common usage is to store all of your virtualenvs in the same place, such as under your home directory. To create a virtualenv for the default Python, likely a version 2, run the following:

$ virtualenv $HOME/envs/sdk

To create an environment for a different version, such as Python 3, run the following:

$ virtualenv -p python3.4 $HOME/envs/sdk3

When you want to enable your environment so that you can develop inside of it, you activate it. To activate an environment, run the /bin/activate script inside of it, like the following:

$ source $HOME/envs/sdk3/bin/activate
(sdk3)$

Once you are activated, you will see the environment name in front of your command prompt. In order to exit that environment, run the deactivate command.

tox¶

We use tox as our test runner, which allows us to run the same test commands against multiple versions of Python. Inside any of the virtualenvs you use for working on the SDK, run the following to install tox into it.:

(sdk3)$ pip install tox

Git¶

The source of the OpenStack SDK is stored in Git. In order to work with our source repository, you must have Git installed on your system. If your system has a package manager, it can likely be had from there. If not, you can find downloads or the source at http://git-scm.com.