## Diagnose deployment failures for ASP.NET Core

### Summary
Deployment diagnostics for an ASP.NET Core app on Ample. Verified on ASP.NET Core: 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.

### Workload
Diagnose deployment failures

### Framework
ASP.NET Core

### Prerequisites
- A ASP.NET Core project (dotnet publish -c Release -o out in the builder, then dotnet .dll on the dotnet-10 template with ASPNETCORE_URLS bound to PORT)
- An Ample account token with servers:write

### Examples
- **ASP.NET Core pattern fixture**: Verified deployment diagnostics on ASP.NET Core.

### 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 ASP.NET Core 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
- **Health check failure**  
  failed deploy reports health_check_failed synchronously  
  **Expectation**: `ample deploy exits 1 with error.code health_check_failed`
- **Runtime log**  
  runtime log carries the app's own error line  
  **Expectation**: `ample logs  --kind runtime shows the framework's error output before the health-check verdict`

### Limitations
- Verified on the dotnet-10 template at s-1vcpu-1gb; other sizes and ASP.NET Core major versions are not verified.
- Region, compliance attestations and request-duration limits are unknown and not claimed.

### 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  
    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.