page:guides:sinatra:cdn assets

Deliver public assets through CDN for Sinatra

Summary: Cdn assets for a Sinatra app on Ample. Verified on Sinatra: a versioned, immutable-cached asset uploaded to a published bucket and served from the CDN URL. 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

• Deliver public assets through CDN for Sinatra
• Where can I host Deliver public assets through CDN built with Sinatra?
• I need a public-origin configuration, versioned asset build and observable cache behavior.

Resource Requirements

• Compute (primitive:compute): Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.
• CDN (primitive:cdn): The CDN host serves objects from published buckets. It does not front app compute and is not a cache or key-value store.

Prerequisites

1. 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).
2. A bucket from ample bucket create with credentials passed as encrypted S3_* environment variables.
3. 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. Publish a bucket for public assets: Publish only the asset bucket; upload versioned keys with an immutable Cache-Control header and build URLs from its public URL. Command: ample bucket publish
3. Verify: Fetch the live URL and /p/versioned-static-assets on the example; on failure read the build and runtime logs. Command: ample logs --kind build

Examples

• Sinatra pattern fixture: Verified CDN assets on Sinatra.

Success Checks

• App responds on its public URL
• Versioned-static-assets 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.
• The CDN serves published-bucket objects only; cache rules, purge and TTL control are not verified.

Cost Estimate

• Currency: USD
• Monthly Amount: 5.0
• Basis: Size prices from pricing.toml at build revision 1ac5595375130d45290090e82ed0f554ccd45405-dirty
• Components:
  • App server, size: s-1vcpu-1gb, quantity: 1.0, monthly amount: 5.0
• Note: Always-on monthly price of the tested sizes; apps auto-pause when idle. Buckets are allocation-priced per quota and not included.

Last Verified At

2026-09-20T23:45:31Z

Formats

• HTML: https://ample.computer/guides/sinatra/cdn-assets
• Markdown: https://ample.computer/guides/sinatra/cdn-assets.md
• JSON: https://api.ample.computer/v1/catalog/recipes/page%3Aguides%3Asinatra%3Acdn-assets

Next Actions

• Browse the catalog index
• Search published recipes by intent, stack and constraints
• Prepare a side-effect-free deployment plan for an authorized project
• Read the existing agent authentication setup
• Browse Sinatra
• Browse Add CDN
• Browse Versioned static assets