page:recipes:marketplace:rails:download delivery

Host marketplace with Rails: authorized file delivery

Deploy a marketplace 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 marketplace-specific behavior as your application code.

Representative Queries

• Host marketplace with Rails: authorized file delivery
• Where can I host Marketplace built with Rails?
• 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

• 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.
• S3-compatible object storage: Buckets are S3-compatible with issued credentials; PutObject and GetObject are verified by canary. Other S3 operations are not verified.

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. 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 Keep private data in an unpublished bucket.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

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

Success Checks

• App responds on its public URL (HTTP GET path: /, expect: ample canary rails patterns)
• Generated-downloads self-test (HTTP GET path: /p/generated-downloads, expect: export=ok rows=3 (with ?token=...; 401 without))

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 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 verified.

Cost Estimate

• Currency: USD
• Monthly Amount: 10.0
• Basis: Size prices from pricing.toml (loaded by the API) at build revision 1ac5595375130d45290090e82ed0f554ccd45405-dirty.
• Components:
  • App server (size: s-1vcpu-1gb, quantity: 1.0, monthly amount: 5.0)
  • Managed PostgreSQL database (size: 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: Rails pattern fixture deployed on Ample; checks passed for generated-downloads and configuration-secrets.
  • Observed At: 2026-09-20T21:55:28Z
  • Implementation Revision: 4f7cb9813c1f-dirty (CLI 4f7cb98)
  • Expires At: 2027-03-19T21:55:28Z
  • Scope: Checks: [/p/generated-downloads], pattern: pattern:generated-downloads, template: ruby-3.4.
• Canary Run: The same Rails app deployed with a --release-command migration; the marker it created was readable after activation.
  • Observed At: 2026-09-20T21:55:28Z
  • Implementation Revision: 4f7cb9813c1f-dirty (CLI 4f7cb98)
  • Expires At: 2027-03-19T21:55:28Z
  • Scope: Pattern: pattern:generated-downloads.

Last Verified At

• 2026-09-20T21:55:28Z

Next Actions

• Browse the catalog index: GET /v1/catalog
• Search published recipes by intent, stack and constraints: POST /v1/catalog/search with query: Host marketplace with Rails: authorized file delivery
• Prepare a side-effect-free deployment plan: POST /v1/catalog/plan
• Read the existing agent authentication setup: GET /mcp/setup
• Browse Marketplace: GET /v1/catalog/nodes/workload%3Amarketplace
• Browse Rails: GET /v1/catalog/nodes/stack%3Aframework-rails
• Browse Generated downloads: GET /v1/catalog/nodes/pattern%3Agenerated-downloads
• Browse Deploy web app: GET /v1/catalog/nodes/intent%3Adeploy-web-app