Contributor Guidelines

Contributor Guidelines

Reporting Bugs

Bugs should be filed on Bug Launchpad for OpenStack-Ansible.

When submitting a bug, or working on a bug, please ensure the following criteria are met:

  • The description clearly states or describes the original problem or root cause of the problem.
  • Include historical information on how the problem was identified.
  • Any relevant logs are included.
  • If the issue is a bug that needs fixing in a branch other than master, please note the associated branch within the launchpad issue.
  • The provided information should be totally self-contained. External access to web services/sites should not be needed.
  • Steps to reproduce the problem if possible.


If it’s a bug that needs fixing in a branch in addition to master, add a ‘<release>-backport-potential’ tag (e.g. liberty-backport-potential). There are predefined tags that will auto-complete.


Please leave the status of an issue alone until someone confirms it or a member of the bugs team triages it. While waiting for the issue to be confirmed or triaged the status should remain as New.


Should only be touched if it is a Blocker/Gating issue. If it is, please set to High, and only use Critical if you have found a bug that can take down whole infrastructures. Once the importance has been changed the status should be changed to Triaged by someone other than the bug creator.

The triaging process is explained on the bug triage documentation page.

General Guidelines for Submitting Code

  • Write good commit messages. We follow the OpenStack “Git Commit Good Practice” guide. if you have any questions regarding how to write good commit messages please review the upstream OpenStack documentation.
  • Changes to the project should be submitted for review via the Gerrit tool, following the workflow documented here.
  • Pull requests submitted through GitHub will be ignored and closed without regard.
  • Patches should be focused on solving one problem at a time. If the review is overly complex or generally large the initial commit will receive a “-2” and the contributor will be asked to split the patch up across multiple reviews. In the case of complex feature additions the design and implementation of the feature should be done in such a way that it can be submitted in multiple patches using dependencies. Using dependent changes should always aim to result in a working build throughout the dependency chain. Documentation is available for advanced gerrit usage too.
  • All patch sets should adhere to the Ansible Style Guide listed here as well as adhere to the Ansible best practices when possible.
  • All changes should be clearly listed in the commit message, with an associated bug id/blueprint along with any extra information where applicable.
  • Refactoring work should never include additional “rider” features. Features that may pertain to something that was re-factored should be raised as an issue and submitted in prior or subsequent patches.
  • New features, breaking changes and other patches of note must include a release note generated using the reno tool. Please see the Documentation and Release Note Guidelines for more information.
  • All patches including code, documentation and release notes should be built and tested locally with the appropriate test suite before submitting for review. See Development and Testing for more information.

Working on Features

  • All feature additions/deletions should be accompanied by a blueprint/spec. e.g. adding additional active agents to neutron, developing a new service role, etc…
  • Before creating blueprint/spec an associated ‘Wishlist Bug’ can be raised on launchpad. This issue will be triaged and a determination will be made on how large the change is and whether or not the change warrants a blueprint/spec. Both features and bug fixes may require the creation of a blueprint/spec. This requirement will be voted on by core reviewers and will be based on the size and impact of the change.
  • All blueprints/specs should be voted on and approved by core reviewers before any associated code will be merged. For more information on blueprints/specs please review the OpenStack documentation regarding Working on Specifications and Blueprints.
  • Once the blueprint work is completed the author(s) can request a backport of the blueprint work into a stable branch. Each backport will be evaluated on a case by case basis with cautious consideration based on how the backport affects any existing deployments. See the Backporting section for more information.
  • Any new OpenStack services implemented which have Tempest tests available must be implemented along with suitable functional tests enabled as part of the feature development in order to ensure that any changes to the code base do not break the service functionality.
  • Feature additions must include documentation which provides reference to OpenStack documentation about what the feature is and how it works. The documentation should then describe how it is implemented in OpenStack-Ansible and what configuration options there are.


  • Backporting is defined as the act of reproducing a change from another branch. Unclean/squashed/modified cherry-picks and complete reimplementations are OK.
  • Backporting is often done by using the same code (via cherry picking), but this is not always the case. This method is preferred when the cherry-pick provides a complete solution for the targeted problem.
  • When cherry-picking a commit from one branch to another the commit message should be amended with any files that may have been in conflict while performing the cherry-pick operation. Additionally, cherry-pick commit messages should contain the original commit SHA near the bottom of the new commit message. This can be done with cherry-pick -x. Here’s more information on Submitting a change to a branch for review.
  • Every backport commit must still only solve one problem, as per the guidelines in General Guidelines for Submitting Code.
  • If a backport is a squashed set of cherry-picked commits, the original SHAs should be referenced in the commit message and the reason for squashing the commits should be clearly explained.
  • When a cherry-pick is modified in any way, the changes made and the reasons for them must be explicitly expressed in the commit message.
  • Refactoring work must not be backported to a “released” branch.
  • Backport reviews should be done with due consideration to the effect of the patch on any existing environment deployed by OpenStack-Ansible. The general OpenStack Guidelines for stable branches can be used as a reference.

Documentation and Release Note Guidelines

Documentation is a critical part of ensuring that the deployers of OpenStack-Ansible are appropriately informed about:

  • How to use the project’s tooling effectively to deploy OpenStack.
  • How to implement the right configuration to meet the needs of their specific use-case.
  • Changes in the project over time which may affect an existing deployment.

To meet these needs developers must submit code comments, documentation and release notes with any code submissions. All forms of documentation should comply with the guidelines provided in the OpenStack Documentation Contributor Guide, with particular reference to the following sections:

  • Writing style
  • RST formatting conventions

Code Comments

Code comments for variables should be used to explain the purpose of the variable. This is particularly important for the role defaults file as the file is included verbatim in the role’s documentation. Where there is an optional variable, the variable and an explanation of what it is used for should be added to the defaults file.

Code comments for bash/python scripts should give guidance to the purpose of the code. This is important to provide context for reviewers before the patch has merged, and for later modifications to remind the contributors what the purpose was and why it was done that way.


OpenStack-Ansible has multiple forms of documentation with different intent.


The statements below regarding the Install Guide and Role Documentation are statements of intent. The work to fulfill the intent is ongoing. Any new documentation submissions should try to help this intent where possible.

The Deployment Guide intends to help deployers deploy OpenStack-Ansible for the first time.

The role documentation (for example, the keystone role documentation) intends to explain all the options available for the role and how to implement more advanced requirements. To reduce duplication, the role documentation directly includes the role’s default variables file which includes the comments explaining the purpose of the variables. The long hand documentation for the roles should focus less on explaining variables and more on explaining how to implement advanced use cases.

Where possible the documentation in OpenStack-Ansible should steer clear of trying to explain OpenStack concepts. Those explanations belong in the OpenStack Manuals or service documentation and OpenStack-Ansible documentation should link to those documents when available, rather than duplicate their content.

Release Notes

Release notes are generated using the reno tool. Release notes must be written with the following guidelines in mind:

  • Each list item must make sense to read without the context of the patch or the repository the patch is being submitted into. The reason for this is that all release notes are consolidated and presented in a long list without reference to the source patch or the context of the repository.
  • Each note should be brief and to the point. Try to avoid multi-paragraph notes. For features the note should typically refer to documentation for more details. For bug fixes the note can refer to a registered bug for more details.

In most cases only the following sections should be used for new release notes submitted with patches:

  • features: This should inform the deployer briefly about a new feature and should describe how to use it either by referencing the variables to set or by referring to documentation.
  • issues: This should inform the deployer about known issues. This may be used when fixing an issue and wanting to inform deployers about a workaround that can be used for versions prior to that which contains the patch that fixes the issue. Issue notes should specifically make mention of what versions of OpenStack-Ansible are affected by the issue.
  • upgrade: This should inform the deployer about changes which may affect them when upgrading from a previous major or minor version. Typically, these notes would describe changes to default variable values or variables that have been removed.
  • deprecations: If a variable has been deprecated (ideally using the deprecation filter), then it should be communicated through notes in this section. Note that if a variable has been removed entirely then it has not been deprecated and the removal should be noted in the upgrade section.

Ansible Style Guide

YAML formatting

When creating tasks and other roles for use in Ansible please create them using the YAML dictionary format.

Example YAML dictionary format:

- name: The name of the tasks
     thing1: "some-stuff"
     thing2: "some-other-stuff"
     - some-tag
     - some-other-tag

Example what NOT to do:

- name: The name of the tasks
  module_name: thing1="some-stuff" thing2="some-other-stuff"
  tags: some-tag
- name: The name of the tasks
  module_name: >
  tags: some-tag

Usage of the “>” and “|” operators should be limited to Ansible conditionals and command modules such as the Ansible shell or command.

Tags and tags conventions

Tags are assigned based on the relevance of each individual item. Higher level includes (for example in the tasks/main.yml) need high level tags. For example, *-config or *-install. Included tasks can have more detailed tags.

The following convention is used:

  • A tag including the word install handles software installation tasks. Running a playbook with --tags <role>-install only deploys the necessary software on the target, and will not configure it to your needs or run any service.
  • A tag including the word config prepares the configuration of the software (adapted to your needs), and all the components necessary to run the service(s) configured in the role. Running a playbook with --tags <role>-config is only possible if the target already ran the tags <role>-install.
  • A tag including the word upgrade handles all the upgrade tasks.

Variable files conventions

The variables files in a role are split in 3 locations:

  1. The defaults/main.yml file
  2. The vars/main.yml file
  3. The vars/<platform specific>.yml file

The variables with lower priority should be in the defaults/main.yml. This allows their overriding with group variables or host variables. A good example for this are default database connection details, default queues connection details, or debug mode.

In other words, defaults/main.yml contains variables that are meant to be overridable by a deployer or a continuous integration system. These variables should be limited as much as possible, to avoid increasing the test matrix.

The vars/main.yml is always included. It contains generic variables that aren’t meant to be changed by a deployer. This includes for example static information that aren’t distribution specific (like aggregation of role internal variables for example).

The vars/<platform specific>.yml is the place where distribution specific content will be stored. For example, this file will hold the package names, repositories urls and keys, file paths, service names/init scripts.

Development cycle checklist

On top of the normal cycle goals, a contributor can help the OpenStack-Ansible development team by performing one of the following recurring tasks:

  • By milestone 1:
    • Community goal acknowledgement
  • By milestone 2:
    • Handle deprecations from upstream project’s previous cycle
    • Handle OpenStack-Ansible roles deprecations from the previous cycle
    • Refresh static elements in roles. For example, update a specific version of the software packages.
    • Bump ceph_stable_release to latest Ceph LTS release in the integrated OpenStack-Ansible repo, and inside the ceph_client role defaults.
  • By milestone 3:
    • Implement features
  • After milestone 3:
    • Feature freeze, bug fixes, and testing improvements
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