# Host admin dashboard with Rails: application activity history

## Summary
Deploy a admin dashboard 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 admin dashboard-specific behavior as your application code.

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

## Resource Requirements
- **primitive:compute**
- **primitive: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.  
   [More Info](/content/discover/primitive/compute/index.html)

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.  
   [More Info](/content/discover/primitive/postgres/index.html)

## 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

## Workflow Steps
1. **Build and start**  
   Command: `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**  
   Command: Copy the approach into your schema; keep migrations idempotent and run them with --release-command.

3. **Deploy**  
   Command: `ample deploy . --name  --public`

4. **Verify**  
   Command: `ample logs  --kind build`

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

## 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 admin dashboard 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:** $10.00  
- **Components:**  
  1. **app server** - $5.00  
  2. **managed PostgreSQL database** - $5.00

## Evidence Summary
1. **Canary Run**  
   Summary: Rails pattern fixture deployed on Ample; checks passed for transactional-workflows and configuration-secrets.  
   Observed At: 2026-09-20T21:55:28Z

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

## Formats
- **HTML:** [View](/content/recipes/admin-dashboard/rails/activity-history/index.html)
- **Markdown:** [View](/content/recipes/admin-dashboard/rails/activity-history.md)
- **JSON:** [View](https://api.ample.computer/v1/catalog/recipes/page%3Arecipes%3Aadmin-dashboard%3Arails%3Aactivity-history)