## Diagnose deployment failures for Sinatra

Deployment diagnostics for a Sinatra app on Ample. Verified on Sinatra: the same app deployed with a deliberate boot failure (CANARY_FAIL=boot): `ample deploy` exited 1 with a coded failure (health_check_failed when the process dies at boot, public_ingress_failed when the framework boots but every request answers 500) and the app's own error line was readable with `ample logs  --kind runtime`, so the cause is read from the framework's output rather than guessed. 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)
- An Ample account token with servers:write

### Workflow Steps
1. **Read the failure code**  
   Deploy is synchronous. Exit 1 with build_failed means the isolated build failed; health_check_failed means the app built but never answered on PORT (it crashed at boot or bound the wrong port); public_ingress_failed means it answered on PORT but the public URL returned an error status (a request handler or bootstrap failed); exit 2 means a required preflight action is blocking.

2. **Read the build log**  
   The last lines name the failing command and its output.  
   **Command:** `ample logs  --kind build`

3. **Read the runtime log**  
   For health_check_failed the runtime log carries the Sinatra process output: in the verified run the deliberate boot failure's own error line was there, followed by the platform's health-check verdict and the start command it ran.  
   **Command:** `ample logs  --kind runtime`

4. **Fix and redeploy once**  
   Change the source, the environment or the command override, then run ample deploy again. Do not loop deploys to poll status; an unchanged redeploy is a no-op.

5. **Verify**  
   Fetch the live URL on the example; on failure read the build and runtime logs.  
   **Command:** `ample logs  --kind build`

### Success Checks
- *Failed deploy reports health_check_failed synchronously*  
  Expect: `ample deploy exits 1 with error.code health_check_failed`
- *Runtime log carries the app's own error line*  
  Expect: `ample logs  --kind runtime shows the framework's error output before the health-check verdict`

### 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.

### Examples
- **Sinatra pattern fixture**  
  Verified deployment diagnostics on Sinatra.  
  Source Reference: `tests/deploy-canaries/sinatra-patterns`.

### Cost Estimate
- **Currency:** USD  
- **Monthly Amount:** 5.0  
- **Basis:** size prices from pricing.toml (loaded by the API)...