page:guides:sinatra:object client

Configure S3-compatible access for Sinatra

Summary

Object storage client for a Sinatra app on Ample. Verified on Sinatra: bucket credentials delivered as encrypted S3_* environment variables and a validated PutObject/GetObject round-trip linked to a database row (upload=ok linked=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.

Representative Queries

• Configure S3-compatible access for Sinatra
• Where can I host Configure S3-compatible access built with Sinatra?
• I need exact S3 endpoint, credentials, operation requirements and an upload/download verification.

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 bucket from ample bucket create with credentials passed as encrypted S3_* environment variables
• An Ample account token with servers:write, buckets: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. Create the bucket and pass its credentials
   Create it once with ample bucket create, then pass endpoint, region, bucket and keys with --env; use path-style addressing.
   Command: ample deploy . --name --public --env S3_ENDPOINT=... --env S3_REGION=... --env S3_BUCKET=... --env S3_ACCESS_KEY_ID=... --env S3_SECRET_ACCESS_KEY=...

3. Verify
   Fetch the live URL and /p/browser-file-uploads on the example; on failure read the build and runtime logs.
   Command: ample logs --kind build

Success Checks

• app responds on its public URL
• browser-file-uploads check from the example

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.
• PutObject and GetObject with path-style addressing are verified; other S3 operations are not.

Cost Estimate

• Currency: USD
• Monthly Amount: 5.0
• Basis: size prices from pricing.toml (loaded by the API) at build revision 1ac5595375130d45290090e82ed0f554ccd45405-dirty
• Components:
  • name: app server
    size: s-1vcpu-1gb
    quantity: 1.0
    monthlyAmount: 5.0

Evidence Summary

• 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: bucket credentials delivered as encrypted S3_* environment variables and a validated PutObject/GetObject round-trip linked to a database row (upload=ok linked=ok).
• Observed At: 2026-09-20T23:45:31Z

Tested Configuration

• Template: ruby-3.4
• Runtime: ruby
• Size: s-1vcpu-1gb
• Install: bundle config set --local path vendor/bundle && bundle config set --local without 'development test' && bundle install
• Start: bundle exec rackup -o 0.0.0.0 -p $PORT

Input Schema

• Required: env, name, path
• Properties:
  • env: Encrypted environment variables (max 50 items, pattern: ^[A-Z][A-Z0-9_]=.$)
  • name: App name (1-63 characters, pattern: ^[a-z0-9-]+$)
  • path: Project directory or ample.toml service (1-512 characters)
  • release_command: Migration command run before activation (max 512 characters)