page:guides:sinatra:deployment diagnostics

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

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

Limitations

Examples

Cost Estimate