# Configure build and start for Rails

## Summary

Build and start for a Rails app on Ample. Verified on Rails: the app built and started with the documented commands and answered on its public HTTPS URL. Build and start: 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.

## 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.)

## Prerequisites

- A Rails project (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)
- An Ample account token with servers:write

## 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. **Build and start.** 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; the server must bind 0.0.0.0 on PORT.
2. **Deploy.** Run the synchronous deploy once and read the result.

```
   ample deploy . --name <app-name> --public
   ```
3. **Verify.** Fetch the live URL on the example; on failure read the build and runtime logs.

```
   ample logs <deployment_id> --kind build
   ```

## Tested examples

- **Rails pattern fixture** (tests/deploy-canaries/rails-patterns): Verified build and start on Rails.

## Success checks

- app responds on its public URL (`/` on the live URL, expect ample canary rails patterns)

## Limitations

- Verified on the ruby-3.4 template at s-1vcpu-1gb; other sizes and Rails major versions are not verified.
- Region, compliance attestations and request-duration limits are unknown and not claimed.

## Cost estimate

Estimated 5.00 USD per month (size prices from pricing.toml at build revision a1b8c38919e59cd035ebabaced73cf84ece24371).
- app server x1 `s-1vcpu-1gb`: 5.00 USD

Always-on monthly price of the tested sizes; apps auto-pause when idle. Buckets are allocation-priced per quota and not included.

## Verification evidence

- canary_run on 2026-09-20T21:55:28Z at revision `4f7cb9813c1f-dirty (CLI 4f7cb98)`: 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); for this guide: the app built and started with the documented commands and answered on its public HTTPS URL. (expires 2027-03-19T21:55:28Z)

Last verified: 2026-09-20T21:55:28Z

## Execution binding

MCP tool `ample_deploy` (registry `mcp:ample_deploy`), schema hash `876465fce906da0c` observed 2026-09-21T03:19:59.461917+00:00 at revision `49962bcade4f`, binding state `current`, required scopes: servers:write.