# Host order tracking with Rails: relational catalog data

Deploy a order tracking built with Rails on Ample using the transactional workflows pattern. Compute runs the app in an isolated microVM behind a public HTTPS URL, a managed PostgreSQL 16 database is auto-provisioned and injected as DATABASE_URL. Verified on Rails: an optimistic version check and an event row written in the same transaction, a stale update rejected, and a history query over the application-owned events (history=2 conflict=rejected). Not separately tested: your domain records, validation rules and concurrency policy; treat the order tracking-specific behavior as your application code.

## Representative Queries
- Host order tracking with Rails: relational catalog data
- Where can I host Order tracking built with Rails?
- I need catalog tables, transactional update logic and application-level access boundaries.

## Resource Requirements
- Compute
- Postgres

## Infrastructure Requirements
1. **Compute**  
   - Status: verified  
   - Summary: Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.
2. **Postgres**  
   - Status: verified  
   - Summary: 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
- A Rails project that builds and starts with the documented commands (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)
- A PostgreSQL driver reading DATABASE_URL at runtime (auto-provisioned when omitted, or supplied with --env)
- An Ample account token with servers:write, databases:read

## Workflow 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. **Implement the pattern on PostgreSQL**  
   The fixture's module implements transactional workflows: an optimistic version check and an event row written in the same transaction, a stale update rejected, and a history query over the application-owned events (history=2 conflict=rejected). Copy the approach into your schema; keep migrations idempotent and run them with --release-command.
3. **Deploy**  
   Run the synchronous deploy once and read the result (exit 0 live, 1 failed, 2 blocked). Re-running with no change is a no-op.
   - Command: ample deploy . --name  --public
4. **Verify**  
   Fetch the live URL and the pattern self-test route(s) (/p/transactional-workflows) from the example; then run your own checks. On failure read `ample logs  --kind build` then `--kind runtime`.
   - Command: ample logs  --kind build

## Success Checks
- App responds on its public URL: **http_get** to `/` expects `ample canary rails patterns`.
- Transactional-workflows self-test: **http_get** to `/p/transactional-workflows` expects `tx=ok history=2 conflict=rejected`.

## Limitations
- Verified on the ruby-3.4 template at s-1vcpu-1gb with the example fixture; other sizes, templates and Rails major versions are not verified.
- The order tracking itself (your domain records, validation rules and concurrency policy) is application code and was not separately tested; the pattern checks are what was verified.

## Cost Estimate
- Currency: USD  
- Monthly Amount: 10.0  
- Components:
  - App server: **s-1vcpu-1gb** - $5.0/month  
  - Managed PostgreSQL database: **s-1vcpu-1gb** - $5.0/month._
- Note: Always-on monthly price of the tested sizes; apps and databases auto-pause when idle.

## Evidence Summary
- **Canary run**:  
  Summary: 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); checks passed for transactional-workflows and configuration-secrets.

## Formats
- [HTML Format](/content/recipes/order-tracking/rails/relational-catalog/index.html)  
- [Markdown Format](/content/recipes/order-tracking/rails/relational-catalog.md)  
- [JSON Format](https://api.ample.computer/v1/catalog/recipes/page%3Arecipes%3Aorder-tracking%3Arails%3Arelational-catalog)

## Next Actions
- **Browse catalog index**: [Operation ID](catalog_index).
- **Search published recipes**: [Operation ID](search_recipes).
- **Prepare deployment plan**: [Operation ID](plan_deployment). 
- **Read authentication setup**: [Operation ID](existing_auth_setup).  
- **Browse Order tracking**: [Operation ID](browse_node).  
- **Browse Rails**: [Operation ID](browse_node).  
- **Browse Transactional workflows**: [Operation ID](browse_node).  
- **Browse Deploy web app**: [Operation ID](browse_node).