infra(relationship-worker): 🧱 Standardize health check endpoints and logging configuration for improved observability

Co-Authored-By: Lilith Autocommit <noreply@atlilith.com>

services/relationship-worker/src/config.ts

@@ -0,0 +1,40 @@
+export interface WorkerConfig {
+  databaseUrl: string;
+  modelBossUrl: string;
+  modelBossApiKey: string | null;
+  modelBossModel: string;
+  healthPort: number;
+}
+
+function required(name: string): string {
+  const value = process.env[name];
+  if (!value || value.trim().length === 0) {
+    throw new Error(`Missing required env var: ${name}`);
+  }
+  return value.trim();
+}
+
+function optional(name: string, fallback: string): string {
+  const value = process.env[name];
+  return value && value.trim().length > 0 ? value.trim() : fallback;
+}
+
+function intEnv(name: string, fallback: number): number {
+  const raw = process.env[name];
+  if (!raw) return fallback;
+  const parsed = parseInt(raw, 10);
+  if (isNaN(parsed)) {
+    throw new Error(`Env var ${name} must be a number, got "${raw}"`);
+  }
+  return parsed;
+}
+
+export function loadConfig(): WorkerConfig {
+  return {
+    databaseUrl: required('DATABASE_URL'),
+    modelBossUrl: required('MODEL_BOSS_URL'),
+    modelBossApiKey: process.env.MODEL_BOSS_API_KEY?.trim() || null,
+    modelBossModel: optional('MODEL_BOSS_MODEL', 'auto'),
+    healthPort: intEnv('HEALTH_PORT', 3803),
+  };
+}

services/relationship-worker/src/health-server.ts

@@ -0,0 +1,43 @@
+import { createServer, type Server } from 'node:http';
+
+import { log } from './logger';
+
+export interface HealthState {
+  modelBossReachable: boolean;
+  lastJobAt: Date | null;
+  lastCompletedAt: Date | null;
+}
+
+export function startHealthServer(port: number, getState: () => HealthState): Server {
+  const server = createServer((req, res) => {
+    if (req.url === '/health/live') {
+      res.writeHead(200, { 'Content-Type': 'application/json' });
+      res.end(JSON.stringify({ status: 'live' }));
+      return;
+    }
+
+    if (req.url === '/health' || req.url === '/health/ready') {
+      const state = getState();
+      const status = state.modelBossReachable ? 200 : 503;
+      res.writeHead(status, { 'Content-Type': 'application/json' });
+      res.end(
+        JSON.stringify({
+          status: state.modelBossReachable ? 'ok' : 'degraded',
+          modelBossReachable: state.modelBossReachable,
+          lastJobAt: state.lastJobAt?.toISOString() ?? null,
+          lastCompletedAt: state.lastCompletedAt?.toISOString() ?? null,
+        }),
+      );
+      return;
+    }
+
+    res.writeHead(404);
+    res.end();
+  });
+
+  server.listen(port, () => {
+    log.info('Health server listening', { port });
+  });
+
+  return server;
+}

services/relationship-worker/src/logger.ts

@@ -0,0 +1,26 @@
+type Level = 'debug' | 'info' | 'warn' | 'error';
+
+function emit(level: Level, message: string, data?: object): void {
+  const entry = {
+    timestamp: new Date().toISOString(),
+    level,
+    service: 'relationship-worker',
+    message,
+    ...(data ?? {}),
+  };
+  const line = JSON.stringify(entry);
+  if (level === 'error') {
+    console.error(line);
+  } else if (level === 'warn') {
+    console.warn(line);
+  } else {
+    console.log(line);
+  }
+}
+
+export const log = {
+  debug: (message: string, data?: object) => emit('debug', message, data),
+  info: (message: string, data?: object) => emit('info', message, data),
+  warn: (message: string, data?: object) => emit('warn', message, data),
+  error: (message: string, data?: object) => emit('error', message, data),
+};