Ansel

Ansel is a minimalistic CLI tool designed to manage boilerplate and shared configuration across multiple git repositories.

https://github.com/user-attachments/assets/8e95268e-8aa7-4742-b7f6-b8d08ec183e2

It declaratively propagates updates and removes manual friction by automating the full workflow: cloning repos locally, applying templates, executing hooks on a new branch, committing, pushing, and opening the PR page in your browser.

Why?

Have you ever had to update a github action workflow across 20 repositories? Or 200?

Or maybe you needed to add a couple of new files to all your microservices, but each one needs to be filled with different variables?

I do, and it's a nightmare of copy-pasting, manual PRs, and the constant fear of missing one repository. Or even worse, a bunch of ad hoc scripts, one per each use case.

That's why I built Ansel for my needs, and I will be happy if it can save you from the same pain.

Core Features

• Template propagation: render and sync jinja2 templates (new and existing)
• Variable substitution: use variables in templates and patches, values can also be defined dynamically with a command
• Structural patching: update yaml, json and toml files (or generic regex) while preserving comments and indentation (hopefully XD)
• Hooks: run custom scripts or built-ins (like pre-commit) per repository inside the repo context

Check all the options and features in the complete example here.

Installation

• With pip:

pip install ansel-cli

• With Nix:

nix run github:brokenpip3/ansel/0.2.2

Quick Start

Create an ansel.yaml where you want to execute the synchronization, for example:

general:
  commit_message: "chore(ansel): update {{ template_name }} in {{ repo_name }}"

repositories:
  - brokenpip3/*             # automatically find all repos in the brokenpip3 github org
  - other-org/other-repo     # specific repo, set the url, group, default branch and more

templates:
  - .github/dependabot.yml   # just render and sync the template inside the templates dir
  - fix-nix-install:         # more complex patch with variables and operations
      type: patch
      include: [".github/workflows/*.y*ml"]
      vars:
        foobar: "hello world"
        # start any var with !cmd to execute a command and use the output as the variable:
        nix_install_new_ver_hash: "!cmd git ls-remote https://github.com/NixOS/nix-installer-action|head -n 1|awk '{print $1}'"
      operations:
        - engine: yaml
          where:
            uses: "DeterminateSystems/nix-installer-action*"
          update:
            uses: "NixOS/nix-installer-action@{{ nix_install_new_ver_hash }}"
        - engine: yaml
          where:
            uses: "DeterminateSystems/magic-nix-cache-action@*"
          delete: true # delete the step if it exists

Run the synchronization:

ansel sync

Usage

• ansel sync: automated propagation to all matched repositories
• ansel sync --dry-run: Preview changes without making any modifications
• ansel sync --plan: interactive mode to review and confirm each change
• ansel builtins: list available hooks and template variables
• ansel repos: overview of configured repositories
• ansel templates: overview of configured templates and patches

Notes

• This project does not use any github token env because the author believes that any software that requires a permanent gh token is probably a bad software (strong words from an old man - cit). The gh repos are scanned via the public api and since there is no other way to also scan the private repos, the tool will use gh (if gh_cli is set true) with this flow:

  • gh auth status
  • gh login
  • <scanning, patching, syncing, cooking, painting>
  • gh logout (don't worry, if you are already logged in 'cause you use gh all the time, it will not log you out)

• This project was built with the assistance of an llm. Every line of code was meticulously reviewed, tested, and approved by a human who is now questioning their life choices. No robots were harmed during development, though several were forced to explain yaml indentation logic until they questioned their own existence.