# Host community forum with Rails: application activity history

Deploy a community forum 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 community forum-specific behavior as your application code.

## Representative Queries
- Host community forum with Rails: application activity history
- Where can I host Community forum built with Rails?
- I need an application-owned event schema and tested history queries; not native platform audit logs.

## Resource Requirements
- **Compute**
- **Postgres**

## Infrastructure Requirements
- **Compute**: Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.
- **Postgres**: Managed PostgreSQL 16 runs in its own microVM and is auto-provisioned when an app needs a database and no DATABASE_URL is supplied.

## Framework
- Rails

## Workload
- Community forum

## Release Status
- Published

## Support Status
- Verified

## Execution Status
- Ready

## Prerequisites
1. 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)
2. A PostgreSQL driver reading DATABASE_URL at runtime (auto-provisioned when omitted, or supplied with --env)
3. An Ample account token with servers:write, databases:read

## 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

## 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**: `ample deploy . --name --public`
4. **Verify**: `ample logs --kind build` then `--kind runtime`.

## Examples
- **Rails pattern fixture**: Multi-pattern Rails app whose transactional workflows module was checked live; the module is under tests/deploy-canaries/_pattern-modules.

## Success Checks
1. **App responds on its public URL**: 
   - **Kind**: http_get  
   - **Path**: /  
   - **Expect**: ample canary rails patterns
2. **Transactional-workflows self-test**:  
   - **Kind**: http_get  
   - **Path**: /p/transactional-workflows  
   - **Expect**: 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 community forum 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  
- **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
1. **Canary Run**: Rails pattern fixture deployed on Ample; checks passed for transactional-workflows and configuration-secrets. Pattern proof: 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.
2. **Canary Run**: The same Rails app deployed with a --release-command migration; the marker it created was readable after activation.

## Last Verified At
- 2026-09-20T21:55:28Z