اكتشاف الخدمات (Service Discovery)

import { ServiceNotFoundError, logContext } from './lib/base_repository';
import Consul from 'consul';

// Repository Pattern — طبقة الوصول إلى Consul
interface ServiceDiscoveryRepository {
  discover(name: string): Promise<string>;
}

class ConsulServiceRepository implements ServiceDiscoveryRepository {
  private readonly consul = new Consul({ host: 'consul', port: 8500 });

  async discover(name: string): Promise<string> {
    const services = await this.consul.agent.service.list();
    const instances = Object.values(services).filter(s => s.Service === name);

    if (instances.length === 0) {
      // Domain Exception — وليس throw new Error('Service not found')
      throw new ServiceNotFoundError(name);
    }

    const instance = instances[Math.floor(Math.random() * instances.length)];
    const url = `http://${instance.Address}:${instance.Port}`;

    // Structured logging مع context
    structuredLog('info', 'Service discovered', { service: name, url });

    return url;
  }
}

# Docker Compose مع خدمة اكتشاف
version: '3.8'
services:
  api-gateway:
    image: nginx
    depends_on:
      - user-service
      - order-service
  user-service:
    image: user-service:latest
    ports:
      - "3001"
  order-service:
    image: order-service:latest
    ports:
      - "3002"

const consul = require('consul')();

app.on('ready', async () => {
  await consul.agent.service.register({
    name: 'user-service',
    address: 'localhost',
    port: 3001,
    check: {
      http: 'http://localhost:3001/health',
      interval: '10s',
    },
  });
});

app.on('shutdown', async () => {
  await consul.agent.service.deregister('user-service');
});

# Kubernetes Service
apiVersion: v1
kind: Service
metadata:
  name: user-service
spec:
  selector:
    app: user-service
  ports:
    - port: 3001
---

apiVersion: v1
kind: Endpoints
metadata:
  name: user-service
subsets:
  - addresses:
      - ip: 10.0.0.1
    ports:
      - port: 3001