@terreno/api-health

Health check plugin for @terreno/api that provides a configurable health endpoint.

Quick Start

import {HealthApp} from "@terreno/api-health";
import {TerrenoApp} from "@terreno/api";

const app = new TerrenoApp({userModel: User})
  .register(new HealthApp())
  .start();

This creates a GET /health endpoint that returns {healthy: true}.

Custom Health Checks

Provide a custom check function for more complex health monitoring:

import {HealthApp} from "@terreno/api-health";
import mongoose from "mongoose";

const healthApp = new HealthApp({
  path: "/api/health",
  check: async () => {
    try {
      await mongoose.connection.db.admin().ping();
      return {
        healthy: true,
        details: {database: "connected"},
      };
    } catch (error) {
      return {
        healthy: false,
        details: {database: "disconnected"},
      };
    }
  },
});

const app = new TerrenoApp({userModel: User})
  .register(healthApp)
  .start();

Options

interface HealthOptions {
  enabled?: boolean;    // Default: true
  path?: string;        // Default: "/health"
  check?: () => Promise<HealthCheckResult> | HealthCheckResult;
}

interface HealthCheckResult {
  healthy: boolean;
  details?: Record<string, any>;
}

Response Codes

• 200 — Service is healthy
• 503 — Service is unhealthy (when healthy: false)

Use Cases

• Load balancer health checks — Simple endpoint for GCP/AWS health monitoring
• Database connectivity — Test connection before accepting requests
• Multi-service checks — Verify external dependencies (Redis, APIs, etc.)
• Kubernetes readiness/liveness probes

Best Practices

• Keep health checks fast (<1s) — they run frequently
• Return specific details for debugging: {database: "connected", cache: "ok"}
• Use /health for liveness, custom paths for readiness checks
• Don't expose sensitive information in health check responses