filter-repo-action

Filter a repository history for mirroring to an untrusted forge.

Use case

Want to make your projects discoverable on centralised forges, but don't want to support the centralisation? Use this action to mirror only a readme and license file, so that interested users can find your repository on a centralised site, but have to leave it to use your code.

Usage

This action filters a local repository using git-filter-repo and writes the result to a target directory.

Example

This example assumes the same user/repo on Codeberg/Forgejo as on GitHub.

on:
  push:
    branches:
      - main

jobs:
  mirror:
    runs-on: codeberg-tiny-lazy
    steps:
      - name: Check out the source repository
        uses: actions/checkout@v6
        with:
          fetch-depth: 0 # fetch all commits; we need history to rewrite it

      - name: Check out the target repository
        run: |
          git clone github.com/${{ forgejo.repository }} target || {
            git init --initial-branch=${{ forgejo.ref_name }} target &&
            git remote set-url origin https://github.com/${{ forgejo.repository }}.git
          }

      - name: Filter repository
        uses: https://codeberg.org/alinnow/filter-repo-action@main
        with:
          source: .
          target: target
          paths: |
            README.md
            LICENSE
          prune_empty: never

      - name: Push filtered repository
        run: |
          cd target
          git push --force --mirror https://${{ secrets.OTHER_FORGE_TOKEN }}@github.com/${{ forgejo.repository }}

It's important to name the secret for the other forge something that is not GITHUB_TOKEN, because this variable name is already used by forgejo, for compatibility with GitHub Actions.

Inputs

Input	Description	Default
source	Path where the source repository is checked out	.
target	Target directory to write the filtered repository	(required)
paths	Paths to include in filtered history (multi-line string)	""
path_globs	Path globs to include in filtered history (multi-line string)	""
prune_empty	Whether to prune empty commits	auto