Keep uv.lock file up-to-date with Dependabot updates

In the past couple of weeks, there has been a lot of interest in the Python community for what started as a new Python package manager, but is now slowly growing into so much more, shipping features faster that people can blog about them.

I’ve been looking at adding it to some projects, but one of the main blocker is that Dependabot doesn’t support it yet.

However, as the project dependencies rely on the standard PEP-621, updating these is already supported by Dependabot, and it sends some PRs for them, however, the lock file (uv.lock) is not updated automatically yet.

To workaround that, I came up with a small workflow powered by GitHub actions:

name: uv

on:
  pull_request:
    paths:
      - 'pyproject.toml'

permissions:
  contents: write
  pull-requests: write

jobs:
  lock:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          token: ${{ secrets.GH_PAT }}
      - uses: astral-sh/setup-uv@v3
        with:
          enable-cache: true
      - run: uv lock
      - uses: stefanzweifel/git-auto-commit-action@v5
        with:
          commit_message: Regenerate uv.lock

Here are a few things to note:

• The workflow only runs on changes to pyproject.toml, which is AFAIK the only file that could cause a lock file change.
• I run the checkout with a Personal Access Token, to trigger the CI build on push. This is explained in the GitHub action I use to push.
• Finally, stefanzweifel/git-auto-commit-action commit and pushes any changes back to the branch, if any.

The fact that I need to set a GitHub token in the repo secrets isn’t ideal, but hopefully support will be added soon.

Alternatively, if you’ve not tied to Dependabot, you can use Renovate instead, which already supports the uv.lock file.

It’s quite nice that we can extend GitHub features like this, the product was quite different a few years ago before actions were introduced.