first commit

apps/api/src/app/health.controller.ts

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+import {
+  Controller,
+  Get,
+  Inject,
+  ServiceUnavailableException,
+} from '@nestjs/common';
+import { InjectConnection } from '@nestjs/mongoose';
+import { Public } from '@task-stream/api/identity/presenters';
+import { REDIS_CLIENT } from '@task-stream/api/shared/infrastructure';
+import Redis from 'ioredis';
+import { Connection } from 'mongoose';
+import { DataSource } from 'typeorm';
+
+@Controller('health')
+export class HealthController {
+  constructor(
+    private readonly postgres: DataSource,
+    @InjectConnection() private readonly mongo: Connection,
+    @Inject(REDIS_CLIENT) private readonly redis: Redis,
+  ) {}
+
+  @Public()
+  @Get()
+  async check() {
+    const checks = await Promise.allSettled([
+      this.postgres.query('SELECT 1'),
+      this.mongo.db?.admin().ping(),
+      this.redis.ping(),
+    ]);
+    const [postgres, mongo, redis] = checks.map((c) =>
+      c.status === 'fulfilled' ? 'up' : 'down',
+    );
+    const result = { status: 'ok', postgres, mongo, redis };
+    if (checks.some((c) => c.status === 'rejected')) {
+      throw new ServiceUnavailableException({ ...result, status: 'degraded' });
+    }
+    return result;
+  }
+}