OpenStack Cookbook Versioning scheme

Include the URL of your launchpad blueprint:

https://blueprints.launchpad.net/openstack-chef/+spec/example

There has been multiple threads on the way that cookbook versioning is done. This doc is to attempt to consolidate and organize and ideally agree upon some guidelines on the way to bump/change work on the versioning for the cookbooks for instance the common cookbook.

Problem description

There is no standardization on the cookbook versioning we have. This doc is the attempt to give some general guidelines to fix this.

Proposed change

General Guidelines

When submitting cookbook patches, it is generally required that the version number (within metadata.rb) is incremented in a manor reflective of the level of the change. Any patch should also update the CHANGELOG.md and if appropriate the README.md should reflect the changes and any relevant how-to instructions. The CHANGELOG.md is our executive summary of changes, it should inform what the change was in a quick manner.

There are some differences between the development of patches on the Master and Stable branches. There is more restrictive and vigorous oversight given to changes on the Stable branches. The Master branch is bleeding edge and can relax the version requirement in some simple cases to allow for increased productivity.

Semantic Versioning

The cookbooks use the Semantic Versioning system (see http://semver.org) The system uses a three part version number, Major.Minor.Patch. For example: 9.2.33

The Major number shouldn’t change within a development branch. It will reflect the number that is the Alphabetized Letter of the base OpenStack release, see: https://wiki.openstack.org/wiki/Releases. An example would be Icehouse being the 9th letter and the 9th release all the stable cookbooks would be 9.Y.Z. When the Master branch becomes stabilized, a new Stable branch will be created from it and the Major number in the Master will be incremented by the core team.

The Minor and Patch numbers will be incremented as described in the branch specific sections below.

Stable Branch

The Stable branch cookbooks must leverage the Semantic Versioning system exclusively. All patches must update the metadata.rb and the CHANGELOG.md at a minimum. All patches should try to be backwards compatible.

Stable Branch Example Situations Level of Change
add a recipe Increment Minor
add a function or method Increment Minor
change Gemfile or Berksfile Increment Minor
backport a fix from Master branch Increment Minor
add attribute for a value in a configuration file with the same default Increment Patch
changing a resource option Increment Patch
add a test Increment Patch
fix a broken recipe Increment Patch
re-factoring recipe or test Increment Patch

The table above shows some examples of different levels of changes introduced by a patch and what part of the version number to increment for Stable branches.

Version Locking

The Stable branches are also locked down by added Berksfile.lock and Gemfile.lock to each cookbook. If any changes are made to the Gemfile, the Gemfile.lock would also have to be updated. If any changes are dependent upon other cookbook changes, then the Berkfile.lock and metadata.rb files would need to be updated accordingly.

Cookbook Dependencies

When a change requires hits to multiple cookbooks, like when adding attributes to Common, the metadata.rb file would need to be updated to reflect that required version level. The Berksfile.lock would also need to be updated with the commit id of the dependent change.

Master Branch

The master cookbook should leverage the Semantic Versioning system lightly. We consider the master branch a fast paced “Work in Progress” until we come to the Release Candidate 1 date (RC-1). This means it will be under rapid and active development where versioning isn’t always required. All patches must update the the CHANGELOG.md at a minimum.

Master Branch Example Situations Level of Change
Branching for a new Stable branch Increment Major
add a recipe Increment Minor
add a function or method Increment Minor
change Gemfile or Berksfile Increment Minor
add attribute for a value in a configuration file with the same default Increment Patch**
changing a resource option Increment Patch**
add a test Increment Patch**
fix a broken recipe Increment Patch**
re-factoring recipe or test Increment Patch**

The table above shows some examples of different levels of changes introduced by a patch and what part of the version number to increment for Master branches.

** There are cases where incrementing the Patch number is not necessary and only updating the CHANGELOG.md is required. To avoid re-base collisions on Patch number changes and allow more rapid development, if the change falls within these guidelines, incrementing the Patch version would not be required. - When the change only effects a single cookbook - When the change is just a simple addition of a new attribute for a template and no other logic change is required - When a patch only effects the tests - When a patch only effect the README or other comments

Version Locking

The Master branch is NOT locked down a Berksfile.lock or Gemfile.lock. Changes to the Berksfile and Gemfile can be made directly.

Cookbook Dependencies

When a change requires hits to multiple cookbooks, like when adding attributes to Common, the metadata.rb file would need to be updated to reflect that required version level.

Implementation

Assignee(s)

Everyone because this is an over arching process ;)

Work Items

None.

Dependencies

None, apart from the community approving these guide lines.

Testing

None.

Documentation Impact

See above, this should also be put on the wiki too.

References

This youtube video is the major discussion about this topic. There has also been multiple comments on the google group.