Automate releases

[merwok]

Proposal:

• Normal PRs go into a develop branch (git-flow style)
• To make a release, we use bumpversion to update files and make a PR to master
• The CI system already runs setup.py check, safety check, check-manifest for all branches
• For release branches, we could push sdist and wheel to TestPyPI (or a Caravan devpi server)
• When the PR is merged, CircleCI makes a tag (unsigned?), pushes it to the repo and uses twine to push wheel and sdist to PyPI

[merwok]

Refined proposal

Pre-release

• Pre-release is a PR from a branch derived from develop into master named like release/something (git-flow again)
• A CI workflow for this branch pattern runs bumpversion and other needed commands, commits and pushes to the PR

Release tagging

• A dev merges the PR
• CI runs for master, with an extra job that creates a tag and pushes it

Release publication

• A workflow configured for tags only creates the sdist and wheel
• These are pushed to PyPI or to CircleCI artifacts if some testing flag is set
• A branch to merge master into dev (+ version bumped to a dev number) is created
• A PR is opened

Nice properties:

• The bot account needs write permissions but only pushes tags or non-master branches
• PRs are protected by status checks and merged by humans
• Boring tasks are done by a bot
• Released artifacts == git tags == PR merge commits on master

Edit: this matches official recommendations https://circleci.com/blog/continuously-deploying-python-packages-to-pypi-with-circleci/

[merwok]

https://packaging.python.org/en/latest/guides/publishing-package-distribution-releases-using-github-actions-ci-cd-workflows/

Publishing package distribution releases using GitHub Actions CI/CD workflows — Python Packaging User Guide