# Host Asset Library with Rails: Data Exports

## Summary
Deploy a asset library built with Rails on Ample using the generated downloads 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: an export query rendered to a CSV artifact stored with metadata in a private bucket and returned only to an authorized caller (401 without token, export=ok rows=3). Not separately tested: your export formats, retention policy and entitlement model; treat the asset library-specific behavior as your application code.

## Representative Queries
- Host asset library with Rails: data exports
- Where can I host Asset library built with Rails?
- I need a scoped export format, artifact generation and authorized download procedure.

## Parent IDs
- workload:asset-library
- stack:framework-rails
- pattern:generated-downloads
- intent:deploy-web-app

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

## Infrastructure Requirements
1. **Compute**
   - 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**
   - 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**
   - Buckets are S3-compatible with issued credentials; PutObject and GetObject are verified by canary. Other S3 operations are not verified.

## 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).
- 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.

## 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 generated downloads: an export query rendered to a CSV artifact stored with metadata in a private bucket and returned only to an authorized caller (401 without token, export=ok rows=3). Copy the approach into your schema; keep migrations idempotent and run them with --release-command.

3. **Wire Object Storage**  
   Create the bucket(s), then 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 (exit 0 live, 1 failed, 2 blocked). Re-running with no change is a no-op. 
   ```  
   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) (/p/generated-downloads) from the example; then run your own checks. On failure read `ample logs  --kind build` then `--kind runtime`.  
   ```  
   ample logs  --kind build
   ```

## Examples
- **Rails Pattern Fixture**: Multi-pattern Rails app whose generated downloads 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. **Generated-Downloads Self-Test**
   - **Kind**: http_get
   - **Path**: /p/generated-downloads
   - **Expect**: export=ok rows=3 (with ?token=...; 401 without)

## 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 asset library itself (your export formats, retention policy and entitlement model) 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.
- PutObject and GetObject with path-style addressing are verified; multipart upload, listing, presigned URLs and lifecycle rules are not.

## Cost Estimate
- **Currency**: USD
- **Monthly Amount**: 10.0
- **Components**:
  1. **App Server**:  
     - Size: s-1vcpu-1gb  
     - Quantity: 1.0  
     - Monthly Amount: 5.0
  2. **Managed PostgreSQL Database**:  
     - Size: 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**: 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 generated-downloads and configuration-secrets. Pattern proof: an export query rendered to a CSV artifact stored with metadata in a private bucket and returned only to an authorized caller (401 without token, export=ok rows=3).
- **Latest Verified**: 2026-09-20T21:55:28Z

## MCP Binding
- **Registry Ref**: mcp:ample_deploy
- **Tool Name**: ample_deploy
- **Binding State**: current

## Unknowns
- Region availability is unknown until a verified region fact is recorded.
- Compliance attestations are unknown; none are claimed.

## Formats
- **HTML**: https://ample.computer/recipes/asset-library/rails/data-exports
- **Markdown**: https://ample.computer/recipes/asset-library/rails/data-exports.md
- **JSON**: https://api.ample.computer/v1/catalog/recipes/page%3Arecipes%3Aasset-library%3Arails%3Adata-exports

## Next Actions
1. **Browse the Catalog Index**
   - **Method**: GET
   - **Path**: /v1/catalog

2. **Search Published Recipes**
   - **Method**: POST
   - **Path**: /v1/catalog/search
   - **Body**: {"limit":5,"query":"Host asset library with Rails: data exports"}

3. **Prepare a Side-effect-free Deployment Plan**
   - **Method**: POST
   - **Path**: /v1/catalog/plan
   - **Body**: {"inputs":{},"projectId":"","recipeId":"page:recipes:asset-library:rails:data-exports","recipeRevision":"r1"}

4. **Read the Existing Agent Authentication Setup**
   - **Method**: GET
   - **Path**: /mcp/setup

5. **Browse Asset Library**
   - **Method**: GET
   - **Path**: /v1/catalog/nodes/workload%3Aasset-library

6. **Browse Rails**
   - **Method**: GET
   - **Path**: /v1/catalog/nodes/stack%3Aframework-rails

7. **Browse Generated Downloads**
   - **Method**: GET
   - **Path**: /v1/catalog/nodes/pattern%3Agenerated-downloads

8. **Browse Deploy Web App**
   - **Method**: GET
   - **Path**: /v1/catalog/nodes/intent%3Adeploy-web-app