page:recipes:subscription content:rails:download delivery
Host subscription content with Rails: authorized file delivery
Summary
Deploy a subscription content 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 subscription content-specific behavior as your application code.
Representative Queries
- Host subscription content with Rails: authorized file delivery
- Where can I host Subscription content built with Rails?
- I need a file entitlement model and an application-enforced download authorization flow.
Resource Requirements
- Compute
- Postgres
- 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.
Framework
Rails
Workload
Subscription content
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 serverreading 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 createwith its credentials passed as encrypted S3_* environment variables - An Ample account token with servers:write, databases:read, buckets:read
Workflow Steps
- Build and start: bundle install into vendor/bundle from Gemfile.lock (development and test groups skipped), then Puma via
rails serverreading PORT on the ruby-3.4 template with RAILS_ENV=production. The server must bind 0.0.0.0 on PORT. - 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.
- 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.
- 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=... - 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 buildthen--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 (expect: ample canary rails patterns)
- Generated-downloads self-test (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 subscription content 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.
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, monthlyAmount: 5.0)
- managed PostgreSQL database (size: s-1vcpu-1gb, quantity: 1.0, monthlyAmount: 5.0)