Microservice Configuration API

Centralized configuration management with type safety, caching, and real-time updates.

What It Does

The Microservice Configuration API provides a centralized, type-safe configuration management system for distributed microservices. It eliminates configuration duplication by storing key-value pairs centrally in Firestore with TTL caching and real-time update notifications.

Key Capabilities

• Centralized Storage: Single source of truth for all configuration
• Type Safety: Generic typing for configuration schemas
• TTL Caching: 5-minute cache with 10,000 entry max
• Real-Time Updates: RxJS observables for config changes
• Environment Override: Prefer environment variables over central config
• Batch Operations: Update multiple keys atomically
• Default Values: Fallback values for missing config
• Bypass Cache: Option for volatile/critical values

Main Components

ConfigurationService<T>

key<Key>(k: Key): Builder<T>
getAll(): Promise<Config>
setMany(config: Partial<Config>): Promise<void>

Builder Pattern

Fluent API for individual keys:

const builder = configService.key('BACKGROUND_JOB_URL')
 
// Access patterns
await builder  // Direct await
await builder.get()  // Explicit get
await builder.get({default: 'http://localhost'})  // With default
await builder.get({envarOverride: true})  // Prefer env var
await builder.getOrError()  // Throw if missing
builder.listen()  // Observable for changes
await builder.set('new-value')  // Update value

Configuration Interface

IPlatformConfig

Predefined schema for Foundation services:

{
  // Infrastructure
  REDIS_HOST: string
  REDIS_PORT: string
  CLOUD_HOST: 'gcp' | 'cpln'
  GVC_ALIAS: string
 
  // Firebase/GCP
  FIREBASE_API_KEY: string
  GCP_PROJECT_NUMBER: string
 
  // Service URLs
  AUTH_REST_URL: string
  BACKGROUND_JOB_REST_URL: string
  MESSAGING_REST_URL: string
  SSE_REST_URL: string
 
  // Storage
  CONTENT_BUCKET: string
  PDF_BUCKET: string
  CNAME: string
  BROWSER_BASE_URL: string
 
  // Defaults & Flags
  DEFAULT_PRODUCT_IDS: string[]
  INITIALIZE_SQL: boolean
  FORCE_APP_ENGINE: boolean
}

Storage Backend

FirestoreConfigurationEngine

• Document: configuration/microservice-config
• All config stored as key-value pairs in single document
• Real-time listeners via Firestore getValueChanges
• Batch upsert for efficient bulk updates

Caching Strategy

• TTL: 5 minutes
• Max Entries: 10,000
• Invalidation: Automatic on setMany() operations
• Bypass: bypassCache: true option

Common Use Cases

• Multi-environment configuration (dev, staging, prod)
• Dynamic feature flags without redeployment
• Service discovery with centralized URLs
• Real-time configuration updates
• Type-safe config access across microservices

What Customers Don’t Have to Build

• Centralized configuration storage
• TTL-based caching infrastructure
• Real-time config change listeners
• Type-safe configuration access
• Environment variable override logic
• Batch configuration updates
• Firestore integration for config
• Configuration validation