# Host community forum with Rails: tenant-scoped workspaces

## Summary
Deploy a community forum built with Rails on Ample using the multi-tenant relational data 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: a tenant column on every row and query, with a cross-tenant read returning nothing (tenant_isolation=ok). Not separately tested: your tenant model, membership and per-tenant authorization; treat the community forum-specific behavior as your application code.

## Representative Queries
- Host community forum with Rails: tenant-scoped workspaces
- Where can I host Community forum built with Rails?
- I need an explicit tenant model and application-enforced tenant isolation tests.

## 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

## 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.

## 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 multi-tenant relational data: a tenant column on every row and query, with a cross-tenant read returning nothing (tenant_isolation=ok). 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 <your-app-name> --public`

4. **Verify**  
   Fetch the live URL and the pattern self-test route(s) (/p/multi-tenant-relational-data) from the example; then run your own checks. On failure read `ample logs <app-name> --kind build` then `--kind runtime`.  
   Command: `ample logs <app-name> --kind build`

## Examples
- **Rails pattern fixture**: Multi-pattern Rails app whose multi-tenant relational data module was checked live; the module is under tests/deploy-canaries/_pattern-modules.
  - Source Reference: `tests/deploy-canaries/rails-patterns`

## Success Checks
- **App responds on its public URL**  
  Kind: `http_get`  
  Path: `/`  
  Expect: `ample canary rails patterns`
- **Multi-tenant-relational-data self-test**  
  Kind: `http_get`  
  Path: `/p/multi-tenant-relational-data`  
  Expect: `tenant_isolation=ok`

## 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 tenant model, membership and per-tenant authorization) 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.