8. Developer Guide

Cluster Genesis development is overseen by a team of IBM engineers.

8.1. Git Repository Model

Development and test is orchestrated within the master branch. Stable release-x.y branches are created off master and supported with bug fixes. Semantic Versioning is used for release tags and branch names.

8.2. Coding Style

Code should be implemented in accordance with PEP 8 – Style Guide for Python Code.

It is requested that modules contain appropriate __future__ imports to simplify future migration to Python3.

8.3. Commit Message Rules

  • Subject line
    • First line of commit message provides a short description of change

    • Must not exceed 50 characters

    • First word after tag must be capitalized

    • Must begin with one of the follwoing subject tags:

      feat:      New feature
      fix:       Bug fix
      docs:      Documentation change
      style:     Formatting change
      refactor:  Code change without new feature
      test:      Tests change
      chore:     Miscellaneous no code change
      Revert     Revert previous commit
  • Body
    • Single blank line seperates subject line and message body
    • Contains detailed description of change
    • Lines must not exceed 72 characters
    • Periods must be followed by single space

Your Commit message can be validated within the tox environment (see below for setup of the tox environment):

cluster-genesis$ tox -e commit_message_validate

8.4. Unit Tests and Linters

8.4.1. Tox

Tox is used to manage python virtual environments used to run unit tests and various linters.

To run tox first install python dependencies:

cluster-genesis$ ./scripts/install.sh

Install tox:

cluster-genesis$ pip install tox

To run all tox test environments:

cluster-genesis$ tox

List test environments:

cluster-genesis$ tox -l

Run only ‘pep8’ test environment:

cluster-genesis$ tox -e pep8

8.4.2. Unit Test

Unit test scripts reside in the cluster-genesis/tests/unit/ directory.

Unit tests can be run through tox:

cluster-genesis$ tox -e py27

Or called directly through python (be mindful of your python environment!):

cluster-genesis$ python -m unittest discover

8.4.3. Linters

Linters are required to run cleanly before a commit is submitted. The following linters are used:

  • Bash: bashate
  • Python: pep8/flake8
  • Ansible: ansible-lint

Linters can be run through tox:

cluster-genesis$ tox -e bashate
cluster-genesis$ tox -e pep8
cluster-genesis$ tox -e ansible-lint

Or called directly (again, be mindful of your python environment!)

8.5. Mock Inventory Generation

Upon completion, Cluster-Genesis provides an inventory of the cluster (saved locally on the deployer at /var/oprc/inventory.yml). This inventory is used to generate an Ansible dynamic inventory. It can also be consumed by other post-deployment services.

A ‘mock’ inventory can be generated from any config.yml file. A tox environment is provided to automatically create a python virtual environment with all required dependencies. By default the ‘config.yml’ file in the cluster-genesis root directory will be used as the input:

cluster-genesis$ tox -e mock_inventory

usage: mock_inventory.py [-h] [config_file] [inventory_file]

positional arguments:
  config_file     Input config.yml to process
  inventory_file  Output inventory.yml path

optional arguments:
  -h, --help      show this help message and exit