9. Development

This section only needs to be read by developers of the pywbem package. People that want to make a fix or develop some extension, and people that want to test the project are also considered developers for the purpose of this section.

9.1. Repository

The repository for pywbem is on GitHub:

https://github.com/pywbem/pywbem

9.2. Setting up the development environment

The development environment is pretty easy to set up.

Besides having a supported operating system with a supported Python version (see Supported environments), it is recommended that you set up a virtual Python environment.

Then, with a virtual Python environment active, clone the Git repo of this project and prepare the development environment with make develop:

$ git clone git@github.com:pywbem/pywbem.git
$ cd pywbem
$ make develop

This will install all prerequisites the package needs to run, as well as all prerequisites that you need for development.

Generally, this project uses Make to do things in the currently active Python environment. The command make help (or just make) displays a list of valid Make targets and a short description of what each target does.

9.3. Building the documentation

The ReadTheDocs (RTD) site is used to publish the documentation for the pywbem package at http://pywbem.readthedocs.io/

This page is automatically updated whenever the Git repo for this package changes the branch from which this documentation is built.

In order to build the documentation locally from the Git work directory, issue:

$ make builddoc

The top-level document to open with a web browser will be build_doc/html/docs/index.html.

9.4. Testing

To run unit tests in the currently active Python environment, issue one of these example commands:

$ make test                                              # Run all unit tests
$ PYTHONPATH=. py.test testsuite/test_cim_obj.py -s      # Run only this test source file
$ PYTHONPATH=. py.test InitCIMInstanceName -s            # Run only this test class
$ PYTHONPATH=. py.test -k InitCIMInstanceName or Bla -s  # py.test -k expressions are possible

Invoke py.test --help for details on the expression syntax of its -k option.

To run the unit tests and some more commands that verify the project is in good shape in all supported Python environments, use Tox:

$ tox                              # Run all tests on all supported Python versions
$ tox -e py27                      # Run all tests on Python 2.7

9.5. Updating the DMTF MOF Test Schema

Pywbem uses DMTF CIM Schemas in its CI testing. The schema used is stored in the form received from the DMTF in the directory testsuite/schema and is expanded and compiled in testsuite/test_mof_compiler.py as part of the tests.

Since the DMTF regularly updates the schema, the pywbem project tries to stay up-to-date with the current schema. At the same time, earlier schemas can be used for testing also by changing the definitions for the dmtf schema to be tested.

The schema used for testing can be modified by modifying the test file:

testsuite/dmtf_mof_schema_def.py

Detailed information on this process is in testsuite/dmtf_mof_schema_def.py

9.6. Developing PyWBEM Ipython Documentation Notebooks

The pywbem developers are using ipython notebooks to demonstrate the use of pywbem. Today we generally have one notebook per operation or group of operations including definition of the operation, references back to the pywbem documentation, and one or more examples (hopefully examples that will actually execute against a wbem server)

These can easily be extended or supplemented using a local ipython or jupyter server by:

1. Install ipython or Jupyter software using pip or pip3. The notebook server may be installed as root or within a python virtual environment. For example:

$ sudo pip install ipython
or
$ sudo pip3 install ipython
or
$ sudo pip install jupyter

The notebook server may be installed as root or within a python virtual environment.

2. Start the local ipython/jupyter notebook server in the notebook directory (pywbem/docs/notebooks) referencing that directory in the command line call:

$ ipython notebook docs/notebooks
or
$ jupyter notebook docs/notebooks

This will start the local ipython/juypter notebook server and on the first page displayed in your web browser all existing pywbem ipython notebooks will be available for editing. New ones can be created using the commands on that ipython server web page.

New and changed notebooks must go through the same contribution process as other components of pywbem to be integrated into the github repository.

9.7. Contributing

Third party contributions to this project are welcome!

In order to contribute, create a Git pull request, considering this:

  • Test is required.
  • Each commit should only contain one “logical” change.
  • A “logical” change should be put into one commit, and not split over multiple commits.
  • Large new features should be split into stages.
  • The commit message should not only summarize what you have done, but explain why the change is useful.
  • The commit message must follow the format explained below.

What comprises a “logical” change is subject to sound judgement. Sometimes, it makes sense to produce a set of commits for a feature (even if not large). For example, a first commit may introduce a (presumably) compatible API change without exploitation of that feature. With only this commit applied, it should be demonstrable that everything is still working as before. The next commit may be the exploitation of the feature in other components.

For further discussion of good and bad practices regarding commits, see: