## The short version

Deploy a product catalog built with Rails on Ample using the public media 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, and a published bucket serves public assets from the CDN host.

## WHAT WAS VERIFIED

Verified on Rails: an object written to a published bucket with an immutable Cache-Control header, a mapping row, and the CDN URL serving it publicly.

## INFRASTRUCTURE

### What it needs

- [Compute](/content/discover/primitive/compute/index.html): verified (Apps run in isolated x86_64 Firecracker microVMs; sizes are the priced VM sizes.)  
- [Postgres](/content/discover/primitive/postgres/index.html): verified (Managed PostgreSQL 16 runs in its own microVM and is auto-provisioned when an app needs a database and no `DATABASE_URL` is supplied.)  
- [S3-compatible object storage](/content/discover/primitive/s3-compatible-object-storage/index.html): verified (Buckets are S3-compatible with issued credentials; PutObject and GetObject are verified by canary. Other S3 operations are not verified.)  
- [CDN](/content/discover/primitive/cdn/index.html): verified (A published bucket's objects are served at its `public_url`. It does not front app compute and is not a cache or key-value store.)

## PREREQUISITES

### Before you start

- 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 and a second, published bucket for public assets (`CDN_*`)  
- An Ample account token with `servers:write`, `databases:read`, `buckets:read`

## STEP BY STEP

### How to do it

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 public media library: an object written to a published bucket with an immutable Cache-Control header, a mapping row, and the CDN URL serving it publicly. 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. Publish only the bucket that serves public assets and reference its CDN URL.

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 <app-name> --public --env S3_ENDPOINT=... --env S3_REGION=... --env S3_BUCKET=... --env S3_ACCESS_KEY_ID=... --env S3_SECRET_ACCESS_KEY=... --env CDN_PUBLIC_URL=...
    ```

5. **Verify**  
    
    Fetch the live URL and the pattern self-test route(s) (/p/public-media-library) from the example; then run your own checks. On failure read `ample logs <deployment_id> --kind build` then `--kind runtime`.
    
    ```
    ample logs <deployment_id> --kind build
    ```

## EXAMPLES

### Tested examples

- **Rails pattern fixture** (`tests/deploy-canaries/rails-patterns`): Multi-pattern Rails app whose public media library module was checked live; the module is under `tests/deploy-canaries/_pattern-modules`.

## SUCCESS CHECKS

### How to know it worked

- app responds on its public URL (`/` on the live URL, expect ample canary rails patterns)  
- public-media-library self-test (`/p/public-media-library` on the live URL, expect a CDN URL whose content is served publicly)

## COST

### Cost estimate

Estimated 10.00 USD per month (size prices from pricing.toml at build revision ca0b484a7a9957c573a88d3a32dc603c3c10135a).

- app server x1 `s-1vcpu-1gb`: 5.00 USD  
- managed PostgreSQL database x1 `s-1vcpu-1gb`: 5.00 USD

Upper-bound monthly price of the tested sizes. Buckets are allocation-priced per quota and not included.

## EVIDENCE

### Verification evidence

- canary_run on 2026-09-20T21:55:28Z at revision `4f7cb9813c1f (CLI 4f7cb98)`: 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 public-media-library and configuration-secrets. Pattern proof: an object written to a published bucket with an immutable Cache-Control header, a mapping row, and the CDN URL serving it publicly. (expires 2027-03-19T21:55:28Z)  
- canary_run on 2026-09-20T21:55:28Z at revision `4f7cb9813c1f (CLI 4f7cb98)`: The same Rails app deployed with a --release-command migration; the marker it created was readable after activation. (expires 2027-03-19T21:55:28Z)

## EXECUTION

### Execution binding

MCP tool `ample_deploy` (registry `mcp:ample_deploy`), schema hash `876465fce906da0c` observed 2026-09-22T00:31:22.774679+00:00 at revision `e6446ceea69b`. Binding state at export: schema_changed. Required scopes: `servers:write`, `databases:read`, `buckets:read`.

## NEXT ACTIONS

### Typed next actions

- Browse the catalog index (`GET /v1/catalog` on the api origin; authentication not required, approval not required)  
- Search published recipes by intent, stack and constraints (`POST /v1/catalog/search` on the api origin; authentication not required, approval not required)  
- Prepare a side-effect-free deployment plan for an authorized project (`POST /v1/catalog/plan` on the api origin; authentication required, approval not required)  
- Read the existing agent authentication setup (`GET /mcp/setup` on the api origin; authentication not required, approval not required)  
- Browse Product catalog (`GET /v1/catalog/nodes/workload%3Aproduct-catalog` on the api origin; authentication not required, approval not required)  
- Browse Rails (`GET /v1/catalog/nodes/stack%3Aframework-rails` on the api origin; authentication not required, approval not required)  
- Browse Public media library (`GET /v1/catalog/nodes/pattern%3Apublic-media-library` on the api origin; authentication not required, approval not required)  
- Browse Deploy web app (`GET /v1/catalog/nodes/intent%3Adeploy-web-app` on the api origin; authentication not required, approval not required)

## ABOUT THIS RECIPE

### Identifiers and status

Recipe `page:recipes:product-catalog:rails:product-media`. Revision r1.

release **published** support **verified** execution **blocked (schema_changed: live tool schema differs from the recorded binding)**

Formats: [HTML](/content/recipes/product-catalog/rails/product-media/index.html) | [Markdown](/content/recipes/product-catalog/rails/product-media.md) | [JSON contract](https://api.ample.computer/v1/catalog/recipes/page%3Arecipes%3Aproduct-catalog%3Arails%3Aproduct-media)