API Release Process (extract for RM GitHub)

DRAFT FOR REVIEW

The API-Release-Guidelines.md file will be created from the below after the review.

Definitions

API releases

In preparation of the public-release of an API version, an API Sub Project can create as many wip, alpha and release-candidate API versions as needed for API development and testing. The API versioning is done as described in the API versioning guidelines here: API versioning. 

The API Sub Project creates a release for an API version as follows:

• a pre-release may be created for an alpha API version. 
• a pre-release must be created for each release-candidate API version.
• a public-release must be created for an API version in order to be published as part of a meta-release.

Public-releases can have an initial or stable status: 

• an initial public-release indicates that the public-release API version is the result of rapid development and is still unstable, e.g. API versions with a v0.x.y version number.
• a stable public-release indicates that the public-release API version is stable and will be maintained.

When planning to deliver a public-release API version into a meta-release, the API Sub Project needs to participate in the meta-release cycle as described below. For more details see also: Meta-release Process.

To be part of a meta-release, (pre-)releases need to be provided as follows:

• the expected (pre-)releases for alpha, release-candidate and public-release API versions need to be provided.
• minimally an initial public-release needs to be provided for the meta-release.
• each (pre-)release must include the required set of API release assets according to the API readiness checklist described below.
• API (pre-)releases are numbered (tagged) using the API release numbering guideline (see below).

Technically, an API release is created using GitHub features:

• A GitHub issue for the release
• A "release PR" for this issue
• A GitHub release package (zip file of the API Sub Project repository)
• A GitHub release tag with the release name rx.y

API release numbering

API release numbers are GitHub tags of the format "rx.y".

IMPORTANT: Release numbers are not related to the API version.

The release numbers shall follow the guidelines described below.

• Release numbers start with x=1 and y=1: r1.1.
• y is incremented by 1 at each subsequent alpha, release-candidate and public-release, and for a maintenance release, e.g. rx.y+1.
• After a meta-release of an API through release rx.y, the next release number for this API is rx+1.1 (y resets to 1).
• In case of maintenance of a release rx.y, the new public-release shall be rx.y+1.

Example of continuous release numbering across the API version.

How to create an API release ? 

An API release is created using the GitHub PR and release features and results in:

• a release tag (following the release numbering guidelines below) on the main or on a maintenance release branch, identifying the release of the API version.
• a release package containing the API's repository with the corresponding API release assets for the released API version (zip file). This is optional for alpha releases.

API releases are numbered (tagged) following the API release numbering guidelines (see section above).

Releasing an API step by step 

This section gives the overview of the steps to release an API. More details can be found in the API Release Process description.

• Create a GitHub issue defining the scope of the targeted API release. Descriptive information in this issue can be reused in the changelog/release notes.
• Create the API release tracker for the target API version as describer here: API release trackers.
• On the main branch, develop the API scope in a "work-in-progress mode" (API version = wip and version in URL is vwip).
  • during development and test, make sure to create and record the required release assets according to the API-Readiness-Checklist file
• Once the required stability is reached, create the "release PR". The “release PR” provides only the following changes: 
  • update the version information in the API OAS definition files (no "wip" in any of the API files).
  • update of the <API name>-API-Readiness-Checklist.md ensuring all required release assets are available.
  • update of the Changelog.md in the repository with new content on the top for each changed API:
    • for an alpha API version, the delta to the previous release
    • for the first release-candidate, all changes since the last public-release
    • for the subsequent release-candidate, only the delta to the previous release candidate
    • for the public-release, the consolidated changes since the last public-release
  • the update of the README.md (as necessary)

• Manage the "release PR" approval, merge the approved "release PR" and create the release

  • An API release is created using the GitHub release feature.
  • The release name shall be the same as the release tag and shall have the following format: rx.y
  • The x.y number shall follow the release numbering scheme as defined in the above section on API release numbering. 
  • Outside the API Sub Project, the release name shall be the API name (for definition see versioning section in the API Design Guidelines) combined with the release number e.g. qod rx.y

Repeat step 3, 4 and 5 for

• alpha releases up to the M3 milestone:  rx.1 through rx.m (with first alpha release: r0.1)
• release-candidates between the M3 and the M4 milestone: rx.m+1 through rx.n
• finishing with the public-release for inclusion in the meta-release: rx.n+1
• maintenance-releases (for MINOR and PATCH updates) after public release: rx.n+2 and up
• next release (for MAJOR updates): same as above, starting at rx+1.0

Example moved back to Confluence