action-template-sync

Sync files from a parent template repository to downstream repos via pull request.

How it works

1. Clones the parent template repo
2. Reads .sync-manifest.yml from the template to determine which files to sync
3. Compares template files against local versions
4. If differences exist, opens (or updates) a PR with the changes

Usage

Add this workflow to any repo that should sync from a template:

# .github/workflows/template-sync.yml
name: Template Sync

on:
  schedule:
    - cron: "0 8 * * 1" # Weekly Monday 8 AM
  workflow_dispatch:

permissions:
  contents: write
  pull-requests: write

jobs:
  sync:
    name: Sync from template
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: gremlinltd/action-template-sync@v1
        with:
          template-repo: gremlinltd/template-rust
          token: ${{ secrets.GITHUB_TOKEN }}

Inputs

Input	Required	Default	Description
template-repo	yes		Parent template repo (e.g., gremlinltd/template-rust)
template-ref	no	main	Branch or tag to sync from
pr-label	no	template-sync	Label for sync PRs
token	yes		GitHub token with contents:write and pull-requests:write

Template manifest

The parent template repo must contain a .sync-manifest.yml in its root:

files:
  - .github/workflows/stale-prs.yml
  - .github/ISSUE_TEMPLATE/bug_report.yml
  - .github/ISSUE_TEMPLATE/feature_request.yml
  - CONTRIBUTING.md
  - SECURITY.md
  - LICENSE

Only files listed in the manifest are synced. Add a new file to the manifest and every downstream repo gets it on next sync.

Ignoring files

Downstream repos can place a .sync-ignore file in their root to skip specific files:

# These files are intentionally customized
CONTRIBUTING.md
.github/pull_request_template.md

Behavior

• Uses a fixed branch chore/template-sync (force-pushed on each run)
• Opens a single PR per repo, updates it if already open
• Files removed from the manifest are left in place (no automatic deletion)
• Missing template files produce a warning, not a failure
• If all files are in sync, no PR is created

License

MIT