# Diagnose deployment failures for Axum

## Summary
Deployment diagnostics for an Axum app on Ample. Verified on Axum: 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: cargo build --release in the rust builder image (stable toolchain, Cargo.lock committed, pure-Rust dependencies), then the release binary on the ubuntu-24.04 template reading PORT and DATABASE_URL.

## Prerequisites
- A Axum project (cargo build --release in the rust builder image (stable toolchain, Cargo.lock committed, pure-Rust dependencies), then the release binary on the ubuntu-24.04 template reading PORT and DATABASE_URL)  
- 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 Axum 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 ubuntu-24.04 template at s-1vcpu-2gb; other sizes and Axum major versions are not verified.  
- Region, compliance attestations and request-duration limits are unknown and not claimed.

## Cost Estimate
| Component     | Size         | Quantity | Monthly Amount |
|---------------|--------------|----------|----------------|
| app server    | s-1vcpu-1gb  | 1.0      | 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.

## Evidence Summary
- **Canary Run**: Axum pattern fixture deployed on Ample with CANARY_FAIL=boot...  
  Observed at: 2026-09-21

## Examples
- **Axum pattern fixture**: Verified deployment diagnostics on Axum.  
  Source Ref: tests/deploy-canaries/axum-patterns

## Next Actions
- **Browse the catalog index**  
- **Search published recipes by intent, stack and constraints**