Host csv import tool with Rails: data exports

Deploy a csv import tool built with Rails 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 Rails: 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 csv import tool-specific behavior as your application code.

Prerequisites

• A Rails project that builds and starts with the documented commands (bundle install into vendor/bundle from Gemfile.lock (development and test groups skipped), then Puma via rails server reading PORT on the ruby-3.4 template with RAILS_ENV=production)
• 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

Resource Requirements

• Compute
• Postgres
• S3-compatible object storage

Workflow Steps

1. Build and start: bundle install into vendor/bundle from Gemfile.lock (development and test groups skipped), then Puma via rails server reading PORT on the ruby-3.4 template with RAILS_ENV=production.
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).
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 Keep private data in an unpublished bucket.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).
5. Verify: Fetch the live URL and the pattern self-test route(s) (/p/generated-downloads) from the example; then run your own checks.

Success Checks

• App responds on its public URL.
• Generated-downloads self-test.

Limitations

• Verified on the ruby-3.4 template at s-1vcpu-1gb with the example fixture; other sizes, templates and Rails major versions are not verified.
• The csv import tool itself (your export formats, retention policy and entitlement model) is application code and was not separately tested; the pattern checks are what was verified.

Cost Estimate

• Monthly Amount: $10.00 USD
• Components:
  • App server: s-1vcpu-1gb, $5.00
  • Managed PostgreSQL database: s-1vcpu-1gb, $5.00

Examples

• Title: Rails pattern fixture
  • Description: Multi-pattern Rails app whose generated downloads module was checked live; the module is under tests/deploy-canaries/_pattern-modules.
  • Source Ref: tests/deploy-canaries/rails-patterns

Evidence Summary

• Rails pattern fixture deployed on Ample, checks passed for generated-downloads and configuration-secrets.