# Host Product Catalog with Phoenix: Relational Catalog Data

## Summary
Deploy a product catalog built with Phoenix 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 Phoenix: 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 product catalog-specific behavior as your application code.

## Representative Queries
- Host product catalog with Phoenix: relational catalog data
- Where can I host Product catalog built with Phoenix?
- I need catalog tables, transactional update logic and application-level access boundaries.

## Resource Requirements
- Compute
- PostgreSQL

## Infrastructure Requirements
### 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.  
  
### 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.

## Framework
Phoenix

## Workload
Product Catalog

## Release Status
Published

## Execution Status
Ready

## Prerequisites
- A Phoenix project that builds and starts with the documented commands (mix deps.get, MIX_ENV=prod mix compile and mix release in the builder, then the release bin script with PHX_SERVER=true on the elixir-1.18 template; PORT, DATABASE_URL and SECRET_KEY_BASE read in config/runtime.exs)
- 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

## Tested Configuration
- **Template:** elixir-1.18  
- **Runtime:** elixir  
- **Size:** s-1vcpu-1gb  
- **Install Command:** mix local.hex --force && mix local.rebar --force && MIX_ENV=prod mix deps.get --only prod  
- **Build Command:** MIX_ENV=prod mix compile && MIX_ENV=prod mix release --overwrite  
- **Start Command:** PHX_SERVER=true _build/prod/rel/$(ls _build/prod/rel | head -n 1)/bin/$(ls _build/prod/rel | head -n 1) start

## Workflow Steps
### 1. Build and Start
mix deps.get, MIX_ENV=prod mix compile and mix release in the builder, then the release bin script with PHX_SERVER=true on the elixir-1.18 template; PORT, DATABASE_URL and SECRET_KEY_BASE read in config/runtime.exs. The server must bind 0.0.0.0 on PORT.

### 2. Implement the Pattern on PostgreSQL
The fixture's module implements transactional workflows: 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). 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  --public

### 4. Verify
Fetch the live URL and the pattern self-test route(s) (/p/transactional-workflows) from the example; then run your own checks. On failure read `ample logs  --kind build` then `--kind runtime`.

Command: ample logs  --kind build

## Examples
### Phoenix Pattern Fixture
- **Description:** Multi-pattern Phoenix app whose transactional workflows module was checked live; the module is under tests/deploy-canaries/_pattern-modules.
- **Source Reference:** tests/deploy-canaries/phoenix-patterns

## Success Checks
- **Description:** app responds on its public URL  
  **Kind:** http_get  
  **Path:** /  
  **Expect:** ample canary phoenix patterns

- **Description:** transactional-workflows self-test  
  **Kind:** http_get  
  **Path:** /p/transactional-workflows  
  **Expect:** tx=ok history=2 conflict=rejected

## Limitations
- Verified on the elixir-1.18 template at s-1vcpu-1gb with the example fixture; other sizes, templates and Phoenix major versions are not verified.
- The product catalog 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:** 10.0  
- **Components:**  
  - **App Server:**  
    - **Size:** s-1vcpu-1gb  
    - **Quantity:** 1.0  
    - **Monthly Amount:** 5.0  
  - **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
- **Kind:** canary_run  
  **Summary:** Phoenix pattern fixture deployed on Ample; checks passed for transactional-workflows and configuration-secrets.

## Last Verified At
2026-09-20T23:45:31Z

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

## Formats
- **HTML:** [View](/content/recipes/product-catalog/phoenix/relational-catalog/index.html)  
- **Markdown:** [View](/content/recipes/product-catalog/phoenix/relational-catalog.md)  
- **JSON:** [View](https://api.ample.computer/v1/catalog/recipes/page%3Arecipes%3Aproduct-catalog%3Aphoenix%3Arelational-catalog)