# Diagnose Deployment Failures for Phoenix

## Summary
Deployment diagnostics for a Phoenix app on Ample. Verified on Phoenix: 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.

## Framework
Phoenix

## Workload
Diagnose deployment failures

## Release Status
Published

## Support Status
Verified

## Execution Status
Unbound

## Docs Only
True

## Prerequisites
- A Phoenix project (mix deps.get, MIX_ENV=prod mix compile and mix release in the builder, then the release bin script with PHX_SERVER=true on the elixir-1.18 template; PORT, DATABASE_URL and SECRET_KEY_BASE read in config/runtime.exs)
- 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 Phoenix 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`

## Limitations
- Verified on the elixir-1.18 template at s-1vcpu-1gb; other sizes and Phoenix 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.

## 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 Phoenix**
- **Browse Troubleshoot deployment**
- **Browse Public web service**