Open Development

Open Development is also part of the four tenets that help OpenStack to move forward. Just like Open Community and Open Source, an Open Development allows for engaging with larger communities and it welcomes a broader group of members. Open Development is the key behind the large developers community and the enormous collaboration model in the project.

Project Team Lead

Every OpenStack project has a Project Team Lead (PTL) who’s elected at the end of every cycle by the active contributors of the project. The PTL is responsible for taking the management leadership of the project it serves. It’s a volunteer position and it does not directly relate to other leadership positions in the Open Source world - i.e BDFL. Projects are driven by their communities and the PTL serves as a tie-breaker when hard decisions need to be made.

Core Reviewers

A core reviewer is a member of the OpenStack community that has volunteered to dedicate time to reviews for a specific project. To become a core reviewer, the interested person is required to have provided enough reviews to the project in order to demonstrate the understanding of the project structure, goals and policies.

Technically speaking, a core reviewer is someone that has +2/-2 powers on the project they are part of. It’s possible to be a core reviewer of several projects and it’s completely fine - and recommended - to step down at any time if your focus and priorities have changed.

Reviews Guidelines

Reviewing is a critical step in OpenStack’s development workflow. It requires reviewers to understand the project in order to be able to provide great feedback and guarantee better quality for that project. Nonetheless, reviews are also a great place for people to start from, to get into OpenStack and start contributing and to learn the project they are interested in.

In order to make the review process easier, OpenStack has developed some guidelines that aim to help reviewers identify potential issues and that also guides them in the interaction with the contributor.

  1. One easy first step is to verify that the proposed code complies with the project’s guidelines. Many projects have a file called HACKING.RST in their repository. This file contains the base guidelines of that project. If the file is not there, then following OpenStack’s general guidelines is the recommend thing to do. Note that these project’s guidelines inherit from the OpenStack’s guidelines anyway.

  2. Verify that the commit message is also compliant with the following criteria:

    1. The title is not longer than 50 characters.

    2. Summary lines should be wrapped at 70 characters.

    3. Make sure the title and the summary describe correctly what the goal of the patch is. Having a bug or a blueprint referenced is not enough. Sometimes the patches are partially fixes for a bigger problem and it’s extremely important to have all that explicitly stated in the commit message.

    4. Make sure the commit message is correctly flagged. If there are API changes then the APIImpact flag should be used. If there are security implications then the SecurityImpact flag should be used. If there are documentation changes then the DocImpact flag should be used.

    5. Make sure blueprints and bugs are correctly referenced in the commit message:

      1. Closes-bug: #12345

      2. Implements-blueprint: my-blueprint-slug

  3. Once the commit message has been reviewed, it’ll be a good moment to dive into the change itself. While doing this, make sure the following points apply as well:

    1. Make sure the code is readable and maintainable.

    2. Make sure the code supports both, python2 and python3. Using six for compatibility is recommended.

In general, reviewing code takes a lot of time and effort and it’s important for every reviewer to dedicate as much time as needed to each review in order to provide better comments and quality. However, when it comes to style and subjective arguments, it’s recommended not to be extremely nitpicky. Finding the right balance and evaluating trade-off is as important as verifying all the above points.

Every reviewer has the ability to vote on patches (+1, 0, -1) and only core reviewers have the ability to +2, -2 and approve patches. Each of these votes have an influence on the patch itself and they communicate agreement, disagreement or errors in the patch. Therefore, these votes must be used properly and it’s the reviewer’s responsibility to do so. Read How to Review Changes the OpenStack Way for guidance on how to use the different votes appropriately.


Whenever a change that introduces a new feature, breaks compatibility or requires discussion needs to be introduced, a specification (spec from now on) is what you’d need. Specs are no more than a RestructuredText file that contains enough information about the proposed change and the problems this change tries to solve.

Specs may change in form depending on the project and target change. However, the workflow to propose these specs is the same for every project. Specs ought to be committed to the project’s spec repository and they follow the same contribution workflow as every other patch. This guarantees that the discussion and proposal remains open and stands behind our open development tenet.

Projects may or may not have deadlines for spec proposals and approvals. These projects may also have a slightly different process and the team responsible for reviewing these specs might not be the same.

Just like OpenStack’s documentation, the merged specs are rendered and published on-line. The url where they can be found is .