Changelog entries

This guide contains instructions for when and how to generate a changelog entry file, as well as information and history about our changelog process.

Overview

Each bullet point, or entry, in our CHANGELOG.md file is generated from a single data file in the changelogs/unreleased/ (or corresponding EE) folder. The file is expected to be a YAML file in the following format:

---
title: "Change[log]s"
merge_request: 1972
author: Black Sabbath
type: added

The merge_request value is a reference to a merge request that adds this entry, and the author key is used to give attribution to community contributors. Both are optional. The type field maps the category of the change, valid options are: added, fixed, changed, deprecated, removed, security, performance, other. Type field is mandatory.

Community contributors and core team members are encouraged to add their name to the author field. GitLab team members should not.

What warrants a changelog entry?

Writing good changelog entries

A good changelog entry should be descriptive and concise. It should explain the change to a reader who has zero context about the change. If you have trouble making it both concise and descriptive, err on the side of descriptive.

The first example provides no context of where the change was made, or why, or how it benefits the user.

Again, the first example is too vague and provides no context.

The first example is too focused on implementation details. The user doesn't care that we changed CSS and HTML, they care about the end result of those changes.

The first example focuses on how we fixed something, not on what it fixes. The rewritten version clearly describes the end benefit to the user (fewer 500 errors), and when (searching commits with Elasticsearch).

Use your best judgement and try to put yourself in the mindset of someone reading the compiled changelog. Does this entry add value? Does it offer context about where and why the change was made?

How to generate a changelog entry

A bin/changelog script is available to generate the changelog entry file automatically.

Its simplest usage is to provide the value for title:

bin/changelog 'Hey DZ, I added a feature to GitLab!'

If you want to generate a changelog entry for GitLab EE, you will need to pass the --ee option:

bin/changelog --ee 'Hey DZ, I added a feature to GitLab!'

At this point the script would ask you to select the category of the change (mapped to the type field in the entry):

>> Please specify the category of your change:
1. New feature
2. Bug fix
3. Feature change
4. New deprecation
5. Feature removal
6. Security fix
7. Performance improvement
8. Other

The entry filename is based on the name of the current Git branch. If you run the command above on a branch called feature/hey-dz, it will generate a changelogs/unreleased/feature-hey-dz.yml file.

The command will output the path of the generated file and its contents:

create changelogs/unreleased/my-feature.yml
---
title: Hey DZ, I added a feature to GitLab!
merge_request:
author:
type:

Arguments

Argument Shorthand Purpose
--amend Amend the previous commit
--force -f Overwrite an existing entry
--merge-request -m Set merge request ID
--dry-run -n Don't actually write anything, just print
--git-username -u Use Git user.name configuration as the author
--type -t The category of the change, valid options are: added, fixed, changed, deprecated, removed, security, performance, other
--help -h Print help message

--amend

You can pass the --amend argument to automatically stage the generated file and amend it to the previous commit.

If you use --amend and don't provide a title, it will automatically use the "subject" of the previous commit, which is the first line of the commit message:

$ git show --oneline
ab88683 Added an awesome new feature to GitLab

$ bin/changelog --amend
create changelogs/unreleased/feature-hey-dz.yml
---
title: Added an awesome new feature to GitLab
merge_request:
author:
type:

--force or -f

Use --force or -f to overwrite an existing changelog entry if it already exists.

$ bin/changelog 'Hey DZ, I added a feature to GitLab!'
error changelogs/unreleased/feature-hey-dz.yml already exists! Use `--force` to overwrite.

$ bin/changelog 'Hey DZ, I added a feature to GitLab!' --force
create changelogs/unreleased/feature-hey-dz.yml
---
title: Hey DZ, I added a feature to GitLab!
merge_request: 1983
author:
type:

--merge-request or -m

Use the --merge-request or -m argument to provide the merge_request value:

$ bin/changelog 'Hey DZ, I added a feature to GitLab!' -m 1983
create changelogs/unreleased/feature-hey-dz.yml
---
title: Hey DZ, I added a feature to GitLab!
merge_request: 1983
author:
type:

--dry-run or -n

Use the --dry-run or -n argument to prevent actually writing or committing anything:

$ bin/changelog --amend --dry-run
create changelogs/unreleased/feature-hey-dz.yml
---
title: Added an awesome new feature to GitLab
merge_request:
author:
type:

$ ls changelogs/unreleased/

--git-username or -u

Use the --git-username or -u argument to automatically fill in the author value with your configured Git user.name value:

$ git config user.name
Jane Doe

$ bin/changelog -u 'Hey DZ, I added a feature to GitLab!'
create changelogs/unreleased/feature-hey-dz.yml
---
title: Hey DZ, I added a feature to GitLab!
merge_request:
author: Jane Doe
type:

--type or -t

Use the --type or -t argument to provide the type value:

$ bin/changelog 'Hey DZ, I added a feature to GitLab!' -t added
create changelogs/unreleased/feature-hey-dz.yml
---
title: Hey DZ, I added a feature to GitLab!
merge_request:
author:
type: added

History and Reasoning

Our CHANGELOG file was previously updated manually by each contributor that felt their change warranted an entry. When two merge requests added their own entries at the same spot in the list, it created a merge conflict in one as soon as the other was merged. When we had dozens of merge requests fighting for the same changelog entry location, this quickly became a major source of merge conflicts and delays in development.

This led us to a boring solution of "add your entry in a random location in the list." This actually worked pretty well as we got further along in each monthly release cycle, but at the start of a new cycle, when a new version section was added and there were fewer places to "randomly" add an entry, the conflicts became a problem again until we had a sufficient number of entries.

On top of all this, it created an entirely different headache for release managers when they cherry-picked a commit into a stable branch for a patch release. If the commit included an entry in the CHANGELOG, it would include the entire changelog for the latest version in master, so the release manager would have to manually remove the later entries. They often would have had to do this multiple times per patch release. This was compounded when we had to release multiple patches at once due to a security issue.

We needed to automate all of this manual work. So we started brainstorming. After much discussion we settled on the current solution of one file per entry, and then compiling the entries into the overall CHANGELOG.md file during the release process.

Return to Development documentation