Release Automation¶

Shaken Fist Python projects use a standardised release workflow based on GitHub Actions, PyPI trusted publishers, and Sigstore signing. This page describes the release infrastructure and how to add it to a new project.

How It Works¶

When a maintainer pushes a git tag matching v* (e.g. v0.6.0), the release.yml workflow:

Builds the package using python3 -m build in a clean venv
Validates the package with twine check
Waits for approval from a required reviewer (via a GitHub environment)
Signs the tag using Sigstore/gitsign (keyless, OIDC-based)
Publishes to PyPI using trusted publishers (no API tokens)
Creates a GitHub Release with the built artifacts and auto-generated release notes

The release job downloads the distribution to a named path and sets fail_on_unmatched_files, so that a release which attaches nothing fails rather than reporting success. Both are load bearing: with a bare download and the action's default of warning on an unmatched glob, an empty release is indistinguishable from a good one.

The workflow can also be started by hand, which runs the build and the twine check as a smoke test and stops there. Everything from the tag signing down is confined to a pushed tag with if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags/v'). Both clauses are needed: aimed at a branch, an unguarded sign-tag would take refs/heads/<branch> for a tag name and force-push refs/tags/refs/heads/<branch>; aimed at an existing tag, a ref-only guard would let the run re-sign and force-push that tag, rewriting a signed object someone may already have verified. Re-running a failed release still works, because "Re-run jobs" replays the original push event.

These runners are persistent and download-artifact extracts into its target rather than replacing it, so a publishing job must not read a directory an earlier job may have left files in. The two jobs solve that differently. publish-pypi checks out, which cleans the workspace with git clean -ffdx, and works in dist/ -- it has to, because pypa/gh-action-pypi-publish delegates to a Docker container action, and the container is given RUNNER_TEMP at /github/runner_temp while ${{ runner.temp }} expands to the host path, which is not there. github-release runs a JavaScript action on the host, so it skips the checkout and downloads into the per-job ${{ runner.temp }} instead.

flowchart TB
    tag["Maintainer pushes v0.6.0 tag"]
    build["Build package"]
    artifacts["Upload artifacts"]
    approve["Wait for reviewer approval<br/>(GitHub environment)"]
    sign["Sign tag with Sigstore"]
    pypi["Publish to PyPI"]
    release["Create GitHub Release"]

    tag --> build
    build --> artifacts
    build --> approve
    approve --> sign
    sign --> pypi
    pypi --> release

Security Properties¶

The release process is designed to eliminate long-lived secrets:

No PyPI API tokens -- authentication uses OIDC trusted publishers, where PyPI verifies the GitHub Actions workflow identity directly
No GPG keys -- tag signing uses Sigstore's keyless signing with OIDC identity certificates, recorded in the Rekor transparency log
Multi-party approval -- the release environment requires a reviewer to approve before publishing proceeds
Protected tags -- tag rulesets prevent unauthorized users from creating release tags
Build provenance -- Sigstore attestations cryptographically link published artifacts to the exact source commit

Adding Release Automation to a Project¶

Prerequisites¶

The project must:

Use pyproject.toml with setuptools_scm (or similar) for version detection from git tags
Not have an old release.sh script (remove it first)

Step 1: Copy the Templates¶

Templates are in templates/release-automation/:

Template	Destination
`release.yml`	`.github/workflows/release.yml`
`RELEASE-SETUP.md`	`RELEASE-SETUP.md` (repo root)

Replace the placeholders in the copied files:

Placeholder	Description	Example
`{{PROJECT_DISPLAY_NAME}}`	Human-readable name	`Occy Strap`
`{{PYPI_PACKAGE_NAME}}`	PyPI package name	`occystrap`
`{{GITHUB_REPO_NAME}}`	GitHub repo name	`occystrap`

Step 2: Configure PyPI Trusted Publisher¶

Log in to pypi.org
If the package has never been published, there is no project to scope a publisher to: add a pending publisher from https://pypi.org/manage/account/publishing/ instead, which also asks for the PyPI project name and becomes an ordinary trusted publisher on the first upload. Otherwise, navigate to your project's Publishing settings
Add a trusted publisher:
Owner: shakenfist
Repository: your repo name
Workflow: release.yml
Environment: release

A wrong value here only fails at publish-pypi, after sign-tag has already pushed the signed tag, so the recovery is the next version rather than a re-pushed tag.

Step 3: Create GitHub Environment¶

Go to Settings > Environments in the repository
Create an environment named release
Add required reviewers
Restrict deployment to tags matching v*

Step 4: Configure Protected Tags¶

Go to Settings > Rules > Rulesets
Create a tag ruleset for v* restricting creation, deletion and force pushes
Add maintainers to the bypass list, and not GitHub Actions: sign-tag collides with none of those rules, so the bypass would only let every workflow create and delete release tags

Tag updates stay unrestricted, so anyone with write access can rewrite a released tag. RELEASE-SETUP.md step 3 explains why the fleet accepts that gap rather than close it with Restrict updates.

Step 5: Remove Old Release Scripts¶

Delete any existing release.sh and commit the removal.

Projects Using This Infrastructure¶

Project	PyPI Package	Status
shakenfist	`shakenfist`	Live
occystrap	`occystrap`	Live
kerbside	`kerbside`	Live
agent-python	`shakenfist-agent`	Added

Verifying a Release¶

Tag Signature¶

gitsign verify --certificate-identity-regexp='.*' \
    --certificate-oidc-issuer='https://token.actions.githubusercontent.com' \
    v0.6.0

PyPI Attestation¶

Check the Provenance section on the package's PyPI page.

Artifact Attestation¶

cosign verify-attestation \
    --certificate-identity-regexp='.*' \
    --certificate-oidc-issuer='https://token.actions.githubusercontent.com' \
    package-0.6.0.tar.gz

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