Propagation of changelogs

Propagation of changelogs

1. Overview

This document outlines how to propagate change logs along with version changes when using jx promote and jx updatebot pr.

1.1 Motivation

At the moment, the change log resulting from upgrading a dependency of an application at best shows to which version of what dependency the upgrade was made. A lot more information would be useful to show, and it should be fairly easy to achieve.

1.2 Goal

The goal is that the resulting change log of a dependency upgrade done using jx promote or jx updatebot pr should show the change logs of the dependency. If there are versions that has not been deployed also the change log for the versions skipped over should be included.

Where possible dependency updates should also be added to the changelog.

The behaviour should be easily adaptable both in pipelines and for cluster repositories.

2. Design proposal

jx changelog create already supports generating a change log document to a file in Markdown format. The content of this file can then be added after a divider (I propose the section divider “-----”) to the body of the pull request by jx promote and jx updatebot pr. When jx promote and jx updatebot pr is updating an existing pull request any existing change log of the PR should be kept and the changelog for the current upgrade is added.

When jx changelog create encounters the merge of a pull request it should include the changelog from its body in the generated changelog. This has the added benefit that manually added or changed changelogs from these pull requests also will turn up in the changelog.

For added context in cluster repos the change in docs/releases.yaml could be used to populate the section Dependency Updates that is already partly supported by jx changelog create.

To support this by default the invocations of jx changelog create, jx promote and jx updatebot pr in jenkins-x/jx3-pipeline-catalog needs to be updated.

Also src/ in jenkins-x/jx3-versions needs to be updated to support changelog for cluster repositories. Since jx changelog create needs tags to create the changelog and tagging currently is only done when KUBEAPPLY = kpt-apply is set in the repository Makefile this will initially be required to get the changelog functionality for cluster repositories.

The command line arguments needs to be amendable using variables to ease customization.

3. Affected repositories

As outlined above the following repositories need changes:

  • jenkins-x-plugins/jx-changelog
  • jenkins-x-plugins/jx-promote
  • jenkins-x-plugins/jx-updatebot
  • jenkins-x/jx3-versions
  • jenkins-x/jx3-pipeline-catalog