Host Marketplace with Phoenix: Authorized File Delivery

Summary

Deploy a marketplace built with Phoenix on Ample using the generated downloads 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. Verified on Phoenix: an export query rendered to a CSV artifact stored with metadata in a private bucket and returned only to an authorized caller (401 without token, export=ok rows=3). Not separately tested: your export formats, retention policy and entitlement model; treat the marketplace-specific behavior as your application code.

Representative Queries

• Host marketplace with Phoenix: authorized file delivery
• Where can I host Marketplace built with Phoenix?
• I need a file entitlement model and an application-enforced download authorization flow.

Resource Requirements

• primitive:compute
• primitive:postgres
• primitive:s3-compatible-object-storage

Infrastructure Requirements

1. 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.
   • Canonical Path: /discover/primitive/compute

2. 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.
   • Canonical Path: /discover/primitive/postgres

3. S3-compatible object storage

   • Status: Verified
   • Summary: Buckets are S3-compatible with issued credentials; PutObject and GetObject are verified by canary. Other S3 operations are not verified.
   • Canonical Path: /discover/primitive/s3-compatible-object-storage

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)
• A bucket from ample bucket create with its credentials passed as encrypted S3_* environment variables
• An Ample account token with servers:write, databases:read, buckets: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 generated downloads: an export query rendered to a CSV artifact stored with metadata in a private bucket and returned only to an authorized caller (401 without token, export=ok rows=3). 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.

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.
   • Command: ample deploy . --name --public --env S3_ENDPOINT=... --env S3_REGION=... --env S3_BUCKET=... --env S3_ACCESS_KEY_ID=... --env S3_SECRET_ACCESS_KEY=...

5. Verify

   • Fetch the live URL and the pattern self-test route(s) (/p/generated-downloads) 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: Multi-pattern Phoenix app whose generated downloads module was checked live; the module is under tests/deploy-canaries/_pattern-modules.

Success Checks

1. App responds on its public URL

   • Kind: http_get
   • Path: /
   • Expect: ample canary phoenix patterns

2. Generated-Downloads Self-Test

   • Kind: http_get
   • Path: /p/generated-downloads
   • Expect: export=ok rows=3 (with ?token=...; 401 without)

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 marketplace itself (your export formats, retention policy and entitlement model) 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.
• PutObject and GetObject with path-style addressing are verified; multipart upload, listing, presigned URLs and lifecycle rules are not.