# Migrate AWS EC2 app: Rails ## Summary Move Rails compute from AWS EC2 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 instance (systemd unit or process manager config) into an env file kept out of the repository. Not migrated automatically: Cron jobs, local files on the instance disk, security-group networking and IAM instance roles are not migrated; use managed databases, buckets and encrypted env instead. Cutover: Add the custom domain with `ample domain add`, update DNS from the instance or load balancer, keep the instance until verified, then stop it. Rollback: keep the source untouched until you confirm; nothing at the source is changed or deleted by this guide. ## Infrastructure requirements - [Compute](/content/discover/primitive/compute/index.html): verified (Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.) - [Postgres](/content/discover/primitive/postgres/index.html): verified (Managed PostgreSQL 16 runs in its own microVM and is auto-provisioned when an app needs a database and no DATABASE_URL is supplied.) ## Prerequisites - Authorized access to the AWS EC2 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 ## Exact tested configuration - template: `ruby-3.4` - runtime: `ruby` - size: `s-1vcpu-1gb` - install: `bundle config set --local path vendor/bundle && bundle config set --local without 'development test' && bundle install` - start: `bundle exec rails server -b 0.0.0.0 -p $PORT` ## Steps 1. **Inventory the source.** List what AWS EC2 app provides beyond the component you are moving. Out of scope here: Cron jobs, local files on the instance disk, security-group networking and IAM instance roles are not migrated; use managed databases, buckets and encrypted env instead. 2. **Source step 1.** Collect the process environment from the instance (systemd unit or process manager config) into an env file kept out of the repository 3. **Source step 2.** Replace the instance's process manager with the repository's start command; Ample supervises the process and restarts it 4. **Source step 3.** Inventory what else runs on the instance: databases, cron, reverse proxy rules, local files 5. **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. ``` ample deploy . --name --public --env-file .env.production ``` 6. **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). 7. **Cut over.** Add the custom domain with `ample domain add`, update DNS from the instance or load balancer, keep the instance until verified, then stop it. 8. **Rollback.** Point DNS or configuration back to the source. The source was never modified; deletion is a separate, user-executed step after validation. ## Tested examples - **Rails pattern fixture (destination)** (tests/deploy-canaries/rails-patterns): Verified destination basis: Rails compute. ## Success checks - destination app responds on its public URL (`/` on the live URL, expect ample canary rails patterns) - configuration-secrets check from the destination example (`/p/configuration-secrets` on the live URL, expect see the pattern fixture checks) - relational-records check from the destination example (`/p/relational-records` on the live URL, expect see the pattern fixture checks) - data or object counts and checksums match the source ## Limitations - Documentation only: nothing is executed automatically and no execution binding is offered. - The source-side procedure is documented from AWS EC2 app's standard tooling and was not executed in this catalog's evidence; the destination side was verified with the pattern fixture. - No full source-product parity is claimed: Cron jobs, local files on the instance disk, security-group networking and IAM instance roles are not migrated; use managed databases, buckets and encrypted env instead. - Verified on the ruby-3.4 template at s-1vcpu-1gb; region, compliance and request-duration limits are unknown. - Managed PostgreSQL 16 only; extensions, connection limits and backup or restore procedures on the managed side are not verified beyond the pattern checks. ## Cost estimate Estimated 10.00 USD per month (size prices from pricing.toml at build revision a1b8c38919e59cd035ebabaced73cf84ece24371). - app server x1 `s-1vcpu-1gb`: 5.00 USD - managed PostgreSQL database x1 `s-1vcpu-1gb`: 5.00 USD Destination always-on monthly price of the tested sizes; apps auto-pause when idle. Source costs are unknown to Ample. ## Verification evidence - canary_run on 2026-09-20T21:55:28Z at revision `4f7cb9813c1f-dirty (CLI 4f7cb98)`: 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 (the app built, started and answered on its public HTTPS URL with encrypted configuration delivered). The source-side export from AWS EC2 app is documented from the vendor's standard tooling and was not executed by this catalog's evidence. (expires 2027-03-19T21:55:28Z) Last verified: 2026-09-20T21:55:28Z ## Execution binding No execution binding. This recipe is documentation only; nothing is executed automatically. ## Next actions - Browse the catalog index - Search published recipes by intent, stack and constraints - Prepare a side-effect-free deployment plan for an authorized project - Read the existing agent authentication setup - Browse AWS EC2 app - Browse Rails - Browse Migrate compute Actions describe possible next steps. They are typed data, not commands, and grant no permission.