brandonbryant12

Absolutely—there’s a clean, idiomatic way to (a) **re‑use start/end date validation across many DTOs** and (b) **run unit + e2e in one Jest invocation with a single coverage report**.

---

## A. Re‑usable date‑range validation for query DTOs

**Goal:** many endpoints accept `start` / `end` query params; we want:

* parse strings → `Date`
* validate each value

brandonbryant12

Below is a **repo‑level structure** that makes GitHub Copilot automatically pick up the right guidance for each part of your monorepo (APIs with NestJS and UIs with Angular), using only what GitHub documents and supports today.

---

## What to create (folder & file layout)

```
your-monorepo/
├─ APIs/
│  └─ ... (NestJS apps & libs)

brandonbryant12

RFC: Implementing Circuit Breaker Functionality in Backstage Backend Using Opossum
Metadata
	•	RFC ID: [Internal - Circuit Breaker Integration]
	•	Authors: Grok (based on user query)
	•	Status: Draft Proposal
	•	Date: September 29, 2025
	•	Version: 1.0
Abstract
This RFC proposes the integration of circuit breaker patterns into the Backstage backend to enhance resilience against failures in API endpoints. We evaluate two options: a global circuit breaker applied to the entire backend and a per-plugin circuit breaker that can be optionally added to individual plugins. We recommend the per-plugin approach for better isolation and extensibility, avoiding modifications to core Backstage components. As an example, we demonstrate how to apply this to the Catalog API plugin.
Introduction

brandonbryant12

networks:
  app_network:
    driver: bridge

services:
  db:
    image: docker.io/postgres:latest
    ports:
      - 5433:5432
    command: ['postgres', '-c', 'log_statement=all']

brandonbryant12

Plan for Implementing Circuit Breaker Functionality in Backstage Backend Using Opossum
Overview
The goal is to add circuit breaker protection to each backend plugin in Backstage using the Opossum library (assuming “opaussum” is a typo for “opossum”). This will ensure that if a plugin’s API endpoints experience repeated failures (e.g., internal errors leading to 500+ status codes), the circuit opens, and subsequent requests to that plugin are rejected with a 503 (Service Unavailable) response to prevent cascading failures. When the circuit half-opens and succeeds, it closes again.
Key requirements:
	•	Per-plugin circuits: Each backend plugin operates on its own independent circuit breaker instance.
	•	Automatic configuration: The implementation uses Backstage’s service override mechanism, so no changes are needed in individual plugins. New plugins added via backend.add(...) will automatically inherit the circuit breaker without any additional code.
This approach treats the circuit breaker as a server-side mech

brandonbryant12

### Limitations of Ingress Annotations for Custom 503 Responses

- **No Direct Customization for Default 503 Errors**: The AWS Load Balancer Controller (LBC) Ingress annotations do not support modifying the response body or content of the default HTTP 503 "Service Unavailable" error that the Application Load Balancer (ALB) generates when a target group has no healthy or registered targets (e.g., no healthy pods). This is a core limitation of the ALB service itself, where such errors are handled at the infrastructure level before traffic reaches Kubernetes resources, and no annotations expose controls to override the hardcoded response.
  
- **Health Check Annotations Are Insufficient**: Annotations like `alb.ingress.kubernetes.io/healthcheck-*` (e.g., path, protocol, success-codes) only configure how the ALB determines target health but do not influence the error response when all targets fail health checks. They cannot inject custom content into the ALB's failure response.

- **Action Annotations Not Applica

brandonbryant12

To implement a circuit breaker that tracks errors per backend plugin in Backstage—triggering a cooldown (circuit open) when a plugin returns too many errors (e.g., 5xx status codes)—without requiring plugin developers to modify their code, customize the httpRouterService using a service factory override. This leverages Backstage’s backend architecture, where each plugin has its own isolated httpRouter instance (an Express Router), mounted at /api/. By overriding the core httpRouterService factory, you can inject a per-plugin circuit breaker middleware that monitors response statuses globally, applying to all plugins, including third-party ones. 20 0 11
This approach uses Opossum to manage the circuit state per plugin, manually recording successes/failures based on response status codes (e.g., counting 5xx as failures). When the error threshold is exceeded, the circuit opens, returning a 503 response for that plugin’s routes during cooldown. It aligns with the circuit breaker pattern for server-side resilience

brandonbryant12

general_settings:
  master_key: sk-ADMIN-KEY        # your admin key
  user_header_name: X-OpenWebUI-User-Email

litellm_settings:
  disable_end_user_cost_tracking: false
  disable_end_user_cost_tracking_prometheus_only: false
  extra_spend_tag_headers:
    - "X-OpenWebUI-User-Email"

brandonbryant12

curl -H "Authorization: Bearer $OPENWEBUI_API_KEY" http://localhost:3000/api/models

brandonbryant12

{
  "$schema": "https://opencode.ai/config.json",

  // 3-a.  Register WebUI as a provider
  "provider": {
    "openwebui": {
      "npm": "@ai-sdk/openai-compatible",   // tells OpenCode the wire protocol
      "name": "Open WebUI (local)",         // label shown in the /models list
      "options": {
        "baseURL": "http://localhost:3000/api"   /* <-- your URL here */