### Host inventory manager with Rails: private attachments  
Deploy an inventory manager built with Rails on Ample using the private document library 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, a private S3-compatible bucket holds objects with credentials delivered as encrypted environment variables. Verified on Rails: a role-to-document access model with negative tests (401 without identity, 403 for the wrong role) and a private-bucket round-trip for the allowed role (private=ok). Not separately tested: your identity integration and role assignments; treat the inventory manager-specific behavior as your application code.

#### Representative Queries  
- Host inventory manager with Rails: private attachments  
- Where can I host Inventory manager built with Rails?  
- I need attachment metadata, access checks and a tested private object access path.

#### Resource Requirements  
- primitive:compute  
- primitive:postgres  
- primitive:s3-compatible-object-storage

#### 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.
3. **S3-compatible object storage**  
   - Status: verified  
   - Summary: Buckets are S3-compatible with issued credentials; PutObject and GetObject are verified by canary. Other S3 operations are not verified.

### 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`.  
   - Ensure server binds to 0.0.0.0 on PORT.
2. **Implement the pattern on PostgreSQL**  
   - The fixture's module implements private document library: a role-to-document access model with negative tests. Copy the approach into your schema; keep migrations idempotent and run them with --release-command.
3. **Wire object storage**  
   - Create the bucket(s) and pass endpoint, region, bucket and keys as --env values. Use path-style addressing. Keep private data in an unpublished bucket.
4. **Deploy**  
   - Run the synchronous deploy once and read the result. Re-running with no change is a no-op.  
   - Command: `ample deploy . --name --public --env S3_ENDPOINT=... --env S3_REGION=... --env S3_BUCKET=... --env S3_ACCESS_KEY_ID=... --env S3_SECRET_ACCESS_KEY=...`
5. **Verify**  
   - Fetch the live URL and the pattern self-test route(s). Then run your own checks. On failure read logs for `--kind build` and `--kind runtime`.  
   - Command: `ample logs --kind build`

#### Prerequisites  
- A Rails project that builds and starts with the documented commands  
- A PostgreSQL driver reading DATABASE_URL at runtime  
- A bucket from `ample bucket create` with its credentials passed as encrypted S3_* environment variables  
- An Ample account token with servers:write, databases:read, buckets:read

### Examples  
1. **Rails pattern fixture**  
   - Description: Multi-pattern Rails app whose private document library module was checked live.  
   - Source Ref: `tests/deploy-canaries/rails-patterns`.

### Limitations  
- Verified on the ruby-3.4 template at s-1vcpu-1gb with the example fixture.

### Cost Estimate  
- **Currency:** USD  
- **Monthly Amount:** 10.0  
- **Basis:** Size prices from pricing.toml at build revision 1ac5595375130d45290090e82ed0f554ccd45405-dirty  
  - Components:  
  1. App server: s-1vcpu-1gb  
     - Quantity: 1.0  
     - Monthly Amount: 5.0  
  2. Managed PostgreSQL database: s-1vcpu-1gb  
     - Quantity: 1.0  
     - Monthly Amount: 5.0

### Success Checks  
1. App responds on its public URL  
2. Private-document-library self-test