Connect Postgres for Sinatra

Summary

Database connection for a Sinatra app on Ample. Verified on Sinatra: a managed PostgreSQL database auto-provisioned and injected as DATABASE_URL, with real queries succeeding at request time (records=ok). Build and start: bundle install into vendor/bundle from Gemfile.lock (development and test groups skipped), then Puma via rackup (config.ru) reading PORT on the ruby-3.4 template.

Prerequisites

• A Sinatra project (bundle install into vendor/bundle from Gemfile.lock (development and test groups skipped), then Puma via rackup (config.ru) reading PORT on the ruby-3.4 template)
• A PostgreSQL driver reading DATABASE_URL at runtime
• An Ample account token with servers:write, databases:read

Workflow Steps

1. Build and start
   bundle install into vendor/bundle from Gemfile.lock (development and test groups skipped), then Puma via rackup (config.ru) reading PORT on the ruby-3.4 template; the server must bind 0.0.0.0 on PORT.

2. Read DATABASE_URL at runtime
   Open connections from the environment inside handlers or a pool; omit DATABASE_URL to auto-provision a managed database or pass --env DATABASE_URL=... for an existing one.

3. Verify
   Fetch the live URL and /p/relational-records on the example; on failure read the build and runtime logs.
   ample logs --kind build

Success Checks

• app responds on its public URL
  • Kind: http_get
  • Path: /
  • Expect: ample canary sinatra patterns
• relational-records check from the example
  • Kind: http_get
  • Path: /p/relational-records
  • Expect: see the pattern fixture checks

Limitations

• Verified on the ruby-3.4 template at s-1vcpu-1gb; other sizes and Sinatra major versions are not verified.
• Region, compliance attestations and request-duration limits are unknown and not claimed.
• Managed PostgreSQL 16 only; extensions, connection limits and backup or restore procedures 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

Evidence Summary

• Kind: canary_run
  • Summary: Sinatra pattern fixture deployed on Ample (bundle install into vendor/bundle from Gemfile.lock (development and test groups skipped), then Puma via rackup (config.ru) reading PORT on the ruby-3.4 template); for this guide: a managed PostgreSQL database auto-provisioned and injected as DATABASE_URL, with real queries succeeding at request time (records=ok).
  • Observed At: 2026-09-20T23:45:31Z

Formats

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• JSON: Link