page:migrate:digitalocean droplet app:rails

Migrate DigitalOcean Droplet app: Rails

Move Rails compute from DigitalOcean Droplet app to Ample, one component at a time. Destination verified on Ample: the app built, started and answered on its public HTTPS URL with encrypted configuration delivered.

Source procedure:

Collect the process environment from the droplet (systemd unit, PM2 or supervisor config) into an env file kept out of the repository. Not migrated automatically: Cron jobs, local upload directories and firewall rules are not migrated; move uploads to a bucket and data to a managed database.

Cutover:

Add the custom domain with ample domain add, update DNS from the droplet IP, keep the droplet until verified, then power it off.

Rollback:

Keep the source untouched until you confirm; nothing at the source is changed or deleted by this guide.

Prerequisites:

Authorized access to the DigitalOcean Droplet app source and its export tooling
An inventory of every component in scope and out of scope
A validated backup or copy before any cutover
An Ample account token with servers:write, databases:read

Workflow Steps:

Inventory the source: List what DigitalOcean Droplet app provides beyond the component you are moving. Out of scope here: Cron jobs, local upload directories and firewall rules are not migrated; move uploads to a bucket and data to a managed database.
Source step 1: Collect the process environment from the droplet (systemd unit, PM2 or supervisor config) into an env file kept out of the repository.
Source step 2: Replace the droplet's process manager and reverse proxy with the repository's start command; Ample provides HTTPS and supervision.
Source step 3: Inventory what else runs on the droplet: databases, cron, local uploads.
Deploy on Ample in parallel: bundle install into vendor/bundle from Gemfile.lock (development and test groups skipped), then Puma via rails server reading PORT on the ruby-3.4 template with RAILS_ENV=production. Pass the exported variables with --env; keep the source running.
Validate before cutover: Run the app's own checks and, for data, compare counts and checksums; the example checks are the pattern self-tests (/p/configuration-secrets, /p/relational-records).
Cut over: Add the custom domain with ample domain add, update DNS from the droplet IP, keep the droplet until verified, then power it off.
Rollback: Point DNS or configuration back to the source. The source was never modified; deletion is a separate, user-executed step after validation.

Success Checks:

Destination app responds on its public URL
Configuration-secrets check from the destination example
Relational-records check from the destination example
Data or object counts and checksums match the source

Limitations:

Documentation only: nothing is executed automatically and no execution binding is offered.
No full source-product parity is claimed: Cron jobs, local upload directories and firewall rules are not migrated; move uploads to a bucket and data to a managed database.
Verified on the ruby-3.4 template at s-1vcpu-1gb; region, compliance and request-duration limits are unknown.

Cost Estimate:

Monthly Amount: $10.00
- App server: 1 x s-1vcpu-1gb = $5.00
- Managed PostgreSQL database: 1 x s-1vcpu-1gb = $5.00

Evidence Summary:

Destination side verified: the Rails pattern fixture deployed on Ample (bundle install into vendor/bundle from Gemfile.lock (development and test groups skipped), then Puma via rails server reading PORT on the ruby-3.4 template with RAILS_ENV=production) and its checks passed.