Migrating Existing Project

Here's the simplest, most reliable way to "adopt" RailsFast into an existing Rails project and start getting updates.

Goal

Link your project’s history to the RailsFast template so future updates are just normal git merges.
Keep your current code as-is during adoption.
Preserve secrets/config with merge guards.

One-time adoption (manual)

Prep

Commit or stash everything: git status should be clean.
Create a safety branch: git checkout -b adopt-railsfast-backup

Add RailsFast as a remote

git remote add railsfast [email protected]:railsfast/railsfast-base.git
git fetch railsfast --prune

Establish a baseline relationship (don’t change your files)

This records the template as a merge parent without altering your tree.

git merge --allow-unrelated-histories -s ours --no-ff -m "Adopt RailsFast upstream at baseline" railsfast/main

Result: histories are now related. Future git merge railsfast/main will bring only changes made in the template since this baseline.

Add merge guards so protected files always keep your local version

If you already have .gitattributes, add lines like:

echo '# RailsFast: Preserve local configuration during template merges' >> .gitattributes
echo 'Dockerfile merge=ours' >> .gitattributes
echo '.kamal/secrets merge=ours' >> .gitattributes
echo 'app/views/pwa/manifest.json.erb merge=ours' >> .gitattributes
echo 'config/application.rb merge=ours' >> .gitattributes
echo 'config/database.yml merge=ours' >> .gitattributes
echo 'config/deploy.yml merge=ours' >> .gitattributes
echo 'config/railsfast.yml merge=ours' >> .gitattributes
echo 'config/credentials.yml.enc merge=ours' >> .gitattributes
echo 'config/master.key merge=ours' >> .gitattributes
echo 'config/db.key merge=ours' >> .gitattributes

Configure the merge driver + rerere:

git config merge.ours.driver true
git config rerere.enabled true
git add .gitattributes
git commit -m "Configure RailsFast merge guards"

(Optional) Record metadata for RailsFast CLI status

If your repo already includes bin/railsfast, you can record the baseline and remote without changing your app:

bin/railsfast init --yes --skip-rename --skip-setup

This writes .railsfast/config.json and remembers the remote/branch/baseline. If you don’t have the scripts yet, you can skip this step.

Verifications

Check relation and baseline:

git log --oneline --graph --decorate --all | head -n 50

See behind count:

git rev-list --count HEAD..railsfast/main