Release procedures

Here we try to keep an up to date record of how Mopidy releases are made. This documentation serves both as a checklist, to reduce the project’s dependency on key individuals, and as a stepping stone to more automation.

Releasing extensions

Extensions that are maintained in the Mopidy organization use a quite stream-lined release procedure.

Make sure that everything has been merged into the main branch on GitHub, and that all CI checks are green.
Perform any manual tests you feel are required.
Bump the version in setup.cfg in line with our strategy. For example, to 2.0.2.
Commit the bumped version:
```
git commit -m "Release v2.0.2"
```
Tag the commit:
```
git tag -m "Release v2.0.2" v2.0.2
```
It is encouraged to use -s to sign the tag if you have a GnuPG setup.
Push to GitHub:
```
git push origin main --follow-tags
```
Go to the GitHub repository’s tags page, e.g. https://github.com/mopidy/mopidy-foo/tags. Find the tag and select “Create release” in the tag’s dropdown menu.
Copy the tag, e.g. v2.0.2 into the “title” field. Write a changelog entry in the description field, and hit “Publish release”.
GitHub Actions now builds the package and uploads it to PyPI.

This procedure has several benefits:

Everyone with commit access can make releases.
No one, except those with direct PyPI access, can make releases without also leaving the source code of what they released publicly available on GitHub, creating an audit log in case of any malicious actions.
The changelog can be amended post-release through the GitHub Releases UI.

The primary drawback of this procedure is that there is no obvious way to maintain a changelog in-between releases. The preferred solution is to make releases often, so that writing up a changelog from the recent Git commits is done in a minute or two.

How to setup this release workflow

If you maintain a Mopidy extension, you’re encouraged to adopt the same procedure.

To setup this on your own repo, you must:

Copy .github/workflows/release.yml from the Mopidy cookiecutter project.
Create an API token in your account settings at PyPI with scope to access the extension’s PyPI package.
Copy the token to a new secret called PYPI_TOKEN in your GitHub repo’s settings. Ignore the section titled “Using this token” on PyPI.

With the release.yml file and the PYPI_TOKEN secret in place, releases should automatically be uploaded to PyPI when you follow the procedure above.

Releasing Mopidy itself

Mopidy itself is a bit more complicated than extensions because the changelog is maintained in the Git repo, and because we maintain multiple branches to be able to work towards the next bugfix release and the next feature release at the same time.

Preparations

Update the changelog. Commit and push it.
Make sure that everything has been merged into the develop branch on GitHub, and that all CI checks are green.
Perform any manual tests you feel are required.

Release

Bump the version in setup.cfg in line with our strategy. For example, to 3.3.0, and set the release date in the changelog.

Commit the bumped version and release date:

git commit -m "Prepare release of v3.3.0"

Merge the release branch (develop in the example) into main:

git checkout main
git pull
git merge --no-ff -m "Release v3.3.0" develop

Tag the commit:
```
git tag -m "Release v3.3.0" v3.3.0
```
It is encouraged to use -s to sign the tag if you have a GnuPG setup.
Push to GitHub:
```
git push origin main --follow-tags
```
Go to the GitHub repository’s tags page at https://github.com/mopidy/mopidy/tags. Find the tag and select “Create release” in the tag’s dropdown menu.
Copy the tag, e.g. v3.3.0 into the “title” field. Write a changelog entry in the description field, and hit “Publish release”.
GitHub Actions now builds the package and uploads it to PyPI.

Post-release

To prepare for further development, merge the main branch back into the develop branch and push it to GitHub:
```
git checkout develop
git merge main
git push origin develop
```
Make sure the new tag is built by Read the Docs, and that the “latest” version shows the newly released version.
Spread the word through an announcement post on the Discourse forum.
Notify distribution packagers, including but not limited to: