## Host form collection with Rails: relational workflow state

### Summary
Deploy a form collection 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 form collection-specific behavior as your application code.

### Representative Queries
- Host form collection with Rails: relational workflow state
- Where can I host Form collection built with Rails?
- I need a domain record schema, validation rules and concurrency behavior.

### Resource Requirements
- primitive:compute
- primitive:postgres

### Infrastructure Requirements
- **Compute**  
  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**  
  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
- 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

### Tested Configuration
- **Template:** ruby-3.4  
- **Runtime:** ruby  
- **Size:** s-1vcpu-1gb  
- **Install Command:** bundle config set --local path vendor/bundle && bundle config set --local without 'development test' && bundle install  
- **Start Command:** bundle exec rails server -b 0.0.0.0 -p $PORT

### 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.
   ```  
   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`.
   ```  
   ample logs  --kind build  
   ```

### Success Checks
- **App responds on its public URL**  
  - Kind: http_get  
  - Path: /  
  - Expected: ample canary rails patterns
- **Transactional-workflows self-test**  
  - Kind: http_get  
  - Path: /p/transactional-workflows  
  - Expected: 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 form collection itself (your domain records, validation rules and concurrency policy) is application code and was not separately tested; the pattern checks are what was verified.
- Region, compliance attestations and request-duration limits are unknown and not claimed.
- Apps auto-pause when idle and wake on the next request; always-on is an operator setting, not a plan feature.
- Managed PostgreSQL 16 only; extensions, connection limits and backup or restore procedures are not verified; apps and their databases are placed together.

### Cost Estimate
- **Currency:** USD  
- **Monthly Amount:** 10.0  
- **Authoritative:** true  
- **Basis:** size prices from pricing.toml (loaded by the API) at build revision 1ac5595375130d45290090e82ed0f554ccd45405-dirty  
- **Components:**  
  - App server: s-1vcpu-1gb, Quantity: 1.0, Monthly Amount: 5.0  
  - Managed PostgreSQL database: s-1vcpu-1gb, Quantity: 1.0, Monthly Amount: 5.0  
- **Note:** Always-on monthly price of the tested sizes; apps and databases auto-pause when idle. Buckets are allocation-priced per quota and not included.

### 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.  
  - Observed At: 2026-09-20T21:55:28Z  
  - Implementation Revision: 4f7cb9813c1f-dirty (CLI 4f7cb98)  
  - Expires At: 2027-03-19T21:55:28Z  
- **Canary Run:**  
  - Summary: The same Rails app deployed with a --release-command migration; the marker it created was readable after activation.  
  - Observed At: 2026-09-20T21:55:28Z  
  - Implementation Revision: 4f7cb9813c1f-dirty (CLI 4f7cb98)  
  - Expires At: 2027-03-19T21:55:28Z

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