Host Asset Library with Phoenix: Relational Workflow State

Deploy an asset library built with Phoenix on Ample using the transactional workflows pattern. Compute runs the app in an isolated microVM behind a public HTTPS URL, and 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 asset library-specific behavior as your application code.

Summary

• Family: Workload recipe
• Framework: Phoenix
• Workload: Asset library
• Release Status: Published
• Support Status: Verified
• Execution Status: Ready

Representative Queries

• Host asset library with Phoenix: relational workflow state
• Where can I host Asset library built with Phoenix?
• I need a domain record schema, validation rules, and concurrency behavior.

Resource Requirements

• primitive:compute
• primitive:postgres

Infrastructure Requirements

Compute

• Primitive ID: primitive: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

• Primitive ID: primitive: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.

Workflow Steps

1. Build and Start
   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. 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
   Command: ample deploy . --name --public

4. Verify
   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 Ref: tests/deploy-canaries/phoenix-patterns

Success Checks

• App responds on its public URL
  Kind: http_get
  Path: /
  Expect: ample canary phoenix patterns

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

Cost Estimate

• Currency: USD
• Monthly Amount: 10.0
• Basis: Size prices from pricing.toml

Components

• App Server
  Size: s-1vcpu-1gb
  Monthly Amount: 5.0
• Managed PostgreSQL Database
  Size: s-1vcpu-1gb
  Monthly Amount: 5.0

Limitations

• Verified on the elixir-1.18 template at s-1vcpu-1gb.
• The asset library itself is application code and was not separately tested.

Next Actions

• Browse the catalog index
  Action ID: browse-catalog
• Prepare a side-effect-free deployment plan
  Action ID: plan:page:recipes:asset-library:phoenix:relational-workflow