Host Reporting Dashboard with Phoenix: Relational Workflow State

Summary

Deploy a reporting dashboard 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 reporting dashboard-specific behavior as your application code.

Resource Requirements

• Compute
• Postgres

Infrastructure Requirements

1. Compute
   Managed 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.

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

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.
   ample deploy . --name <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 <deployment_id> --kind build then --kind runtime.
   ample logs --kind build

Success Checks

• App responds on its public URL.
• Transactional-workflows self-test.

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 reporting dashboard 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: $10.00

Breakdown

1. App server (s-1vcpu-1gb) - $5.00
2. Managed PostgreSQL database (s-1vcpu-1gb) - $5.00

• Always-on monthly price of the tested sizes; apps and databases auto-pause when idle.

Evidence Summary

1. Canary Run: Phoenix pattern fixture deployed on Ample; checks passed for transactional-workflows and configuration-secrets.
2. Canary Run: The same Phoenix app deployed with a --release-command migration; the marker it created was readable after activation.

Next Actions

• Browse the catalog index.
• Search published recipes by intent, stack and constraints.
• Prepare a side-effect-free deployment plan for an authorized project.