Introduction to OpenMDAO Development Process

This documentation for OpenMDAO developers attempts to explain the OpenMDAO development process and how to interact with the various tools the project uses for configuration management, testing, deployment, etc. The source files for this tutorial can be found in the docs/dev-guide directory in the top level directory of your OpenMDAO source branch.

System Configuration

Some steps of the development process, e.g., downloading a branch of the source repository and downloading Python eggs, require network access. If you’re behind an http proxy, you may have to set the http_proxy environment variable on your system in order for Bazaar and virtualenv to function properly.

Getting Started

Before you can start working on source code or running tests, you need to get your own copy of the source code. We use Bazaar, for version control, so you’ll need to have that installed on your system. To install all of the packages you’ll need to run OpenMDAO, just run the script found at the top of the source repository. Under the covers, it uses virtualenv to build the OpenMDAO virtual environment.

Bazaar User Setup

If you have not previously used Bazaar on a particular machine where you intend to work with Bazaar repositories, you should run the whoami command so that Bazaar will know your email address. You need to supply your first and last name and your email address in the following way:

bzr whoami "Joe Cool <>"

This way, your contact information will be included whenever you commit to a repository on that machine.

Code Location

The Bazaar repository for the OpenMDAO source code is available on Launchpad. You can get a copy of the repository as follows:

bzr branch lp:openmdao <your_branch_name>

To submit patches you must upload your branch to the openmdao project on Launchpad and request that it be merged. Please see Pushing a Branch Back to Launchpad

Layout of a Source Repository

Within an OpenMDAO branch repository, the directory structure will look like this:

The directory containing the the OpenMDAO virtual environment. Note that this is not part of the source repository. You will build it by running the script that sits at the top of the source repository.
All Sphinx user documentation for OpenMDAO. The documentation is broken up into several major documents, each found in a separate subdirectory, e.g., arch-doc contains the Architecture Document, dev-guide contains the Developer’s Guide, and user-guide contains the User’s Guide.
Python package containing all infrastructure source for OpenMDAO.
Python package containing source for the OpenMDAO standard library of modules.
Python package containing source for various Python utility routines used by OpenMDAO developers.
Python package containing source for various OpenMDAO plugins used for testing.
Python package containing examples of using OpenMDAO.
Miscellaneous scripts and configuration files used by OpenMDAO developers.
Contains source to be packaged into Python eggs that are releasable separately from OpenMDAO. These eggs may or may not depend upon OpenMDAO. Eggs that have not yet been approved to be part of openmdao.lib can live here, as long as their license is compatible with NOSA. No proprietary code or GPL code can live in the OpenMDAO repository.

Layout of a Namespace Package

OpenMDAO is large enough that it makes sense to split it up into multiple Python packages, but we want all of those packages to be under the umbrella of openmdao. To do this in Python, we use what is called a namespace package. Namespace packages all have a similar directory layout. Currently in OpenMDAO, openmdao.main, openmdao.lib,, openmdao.util and openmdao.test are all namespace packages that are in the openmdao namespace. They all have a layout like this:

The top level directory for the package denoted by <package>. This contains the script which is used to build and create an egg for the package.
Contains all of the package source code.
Contains a special file and a <package> subdirectory.
This is where the actual source code, usually a bunch of Python files, is located. There could be a standard Python package directory structure under this directory as well.

Creating Your Branch

To create a branch, use the command:

bzr branch lp:openmdao <branch_name>

where <branch_name> is the name you are giving to the top level directory of your branch repository. The name should reflect the purpose of the branch to avoid confusion in the case where you have multiple branches active at the same time. If you do not supply <branch_name>, the name by default will be the last part of the source repository URI, which in this case is openmdao.

At Glenn Research Center (GRC), we name branches based on ticket numbers in the bug tracker, and we use the form T<ticket_number>-<desc> where ticket_number is the bug tracker ticket number and <desc> is a short description of the branch. For example, T0029-workflow_fix.

After you’ve created your branch, run the following:


from the top level of your branch directory. This will create a devenv directory in your current directory and will install all of the necessary python packages there. The next step is to activate your virtual environment. This requires that you are running the bash shell if you are on a linux or OS X machine. If you are not running the bash shell, just type bash before moving on to the next step.

Change your directory to devenv and run:

source bin/activate

or, on Windows


At this point, your devenv directory should contain the following subdirectories:

Contains python and a number of other scripts that are associated with the python packages that are installed in the virtual environment. On Windows, this directory is called Scripts
Contains Python standard library and installed modules.
Contains Python C header files.
Contains miscellaneous files that don’t fit in bin, lib, or include.