Host csv import tool with Phoenix: relational workflow state

Summary

Deploy a csv import tool 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 csv import tool-specific behavior as your application code.

Representative Queries

• Host csv import tool with Phoenix: relational workflow state
• Where can I host CSV import tool built with Phoenix?
• I need a domain record schema, validation rules and concurrency behavior.

Resource Requirements

• Compute
• Postgres

Infrastructure Requirements

• Compute: Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.
• 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.

Framework

Phoenix

Workload

CSV import tool

Release Status

Published

Support Status

Verified

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: mix local.hex --force && mix local.rebar --force && MIX_ENV=prod mix deps.get --only prod
• Build: MIX_ENV=prod mix compile && MIX_ENV=prod mix release --overwrite
• Start: 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 <deployment-name> --kind build then --kind runtime. Command: ample logs --kind build.

Examples

• Phoenix pattern fixture: Multi-pattern Phoenix app whose transactional workflows module was checked live; the module is under tests/deploy-canaries/_pattern-modules.

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.

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 csv import tool itself (your domain records, validation rules and concurrency policy) 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.

Cost Estimate

• Currency: USD
• Monthly Amount: 10.0
• Basis: size prices from pricing.toml (loaded by the API) at build revision
• Components:
  • App server: s-1vcpu-1gb, Quantity: 1.0, Monthly Amount: 5.0
  • Managed PostgreSQL database: 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: Phoenix pattern fixture deployed on Ample (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; checks passed for transactional-workflows and configuration-secrets). Pattern proof: 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).

Next Actions

• Browse the catalog index: GET /v1/catalog
• Search published recipes by intent, stack and constraints: POST /v1/catalog/search
• Prepare a side-effect-free deployment plan for an authorized project: POST /v1/catalog/plan
• Read the existing agent authentication setup: GET /mcp/setup
• Browse CSV import tool: GET /v1/catalog/nodes/workload%3Acsv-import-tool
• Browse Phoenix: GET /v1/catalog/nodes/stack%3Aframework-phoenix
• Browse Transactional workflows: GET /v1/catalog/nodes/pattern%3Atransactional-workflows
• Browse Deploy web app: GET /v1/catalog/nodes/intent%3Adeploy-web-app