使用Typeorm和Express.js的无服务器Typescript Rest API

Question

我是Node.js的新手。目前，我在Heroku上有一个基于微服务架构的工作系统，我的目标是将我们的基础设施改为AWS Lambda，使用带有Typescript的Serverless，同时也从Sequelize切换到TypeORM，并继续使用express.js作为Restful API框架。

我试图让所有这些东西一起工作，最终在对我的服务运行基本的GET请求时(使用sls脱机运行)，我收到了Cannot Get /documents

我确信问题出在app.ts。路由是空的，但我不知道如何修复它。

我已经尝试了许多其他选项，但这个选项似乎与数据库一起工作得很好，它甚至自动迁移了我的实体并在我的数据库中正确地创建了表。

任何提示或指导都将不胜感激。

我的代码：

//serverless.ts

import type { Serverless } from 'serverless/aws';

const serverlessConfiguration: Serverless = {
  service: {
    name: 'iod-typeorm-test',
    // app and org for use with dashboard.serverless.com
    // app: your-app-name,
    // org: your-org-name,
  },
  frameworkVersion: '2',
  custom: {
    webpack: {
      webpackConfig: './webpack.config.js',
      includeModules: true
    }
  },
  // Add the serverless-webpack plugin
  plugins: ['serverless-webpack','serverless-offline'],
  provider: {
    name: 'aws',
    profile: '01iod',
    region: 'eu-central-1',
    runtime: 'nodejs12.x',
    apiGateway: {
      minimumCompressionSize: 1024,
    },
    environment: {
      AWS_NODEJS_CONNECTION_REUSE_ENABLED: '1',
    },
  },
  functions: {
    hello: {
      handler: 'handler.hello',
      events: [
        {
          http: {
            method: 'get',
            path: '/documents',
          }
        },
        {
          http: {
            method: 'post',
            path: '/documents',
          }
        }
      ]
    }
  }
}

module.exports = serverlessConfiguration;

//ormconfig.json
{
   "type": "postgres",
   "host": "localhost",
   "port": 5432,
   "username": "root",
   "password": "password",
   "database": "myService",
   "synchronize": true,
   "logging": true,
   "uuidExtension": true,
   "keepConnectionAlive": true,
   "entities": [
      "src/entity/**/*.ts"
   ],
   "migrations": [
      "src/migration/**/*.ts"
   ],
   "subscribers": [
      "src/subscriber/**/*.ts"
   ],
   "cli": {
      "entitiesDir": "src/entity",
      "migrationsDir": "src/migration",
      "subscribersDir": "src/subscriber"
   }
}

//handler.ts
import "reflect-metadata";
import { createServer, proxy } from 'aws-serverless-express';
import { Context } from 'aws-lambda';
import { configureApp } from './app';

const binaryMimeTypes: string[] = [
  'application/json'
];
const app = configureApp();
const server = createServer(app, undefined, binaryMimeTypes);

export const hello = (event: any, context: Context) =>
  proxy(server, event, context);

//app.ts
import * as express from 'express';
import { json, urlencoded } from 'body-parser';
import * as cors from 'cors';
import { eventContext } from 'aws-serverless-express/middleware';
import {createConnection} from "typeorm";
import {Routes} from "./src/routes/routes"
import {Request, Response} from "express";
import * as bodyParser from "body-parser";

export function configureApp() {
  const app = express();

  createConnection().then(async connection => {

    app.use(cors());
    app.use(json());
    app.use(urlencoded({ extended: true }));
    app.use(eventContext());

    // create express app
    app.use(bodyParser.json());
  
    // register express routes from defined application routes
    Routes.forEach(route => {
        (app as any)[route.method](route.route, (req: Request, res: Response, next: Function) => {
            const result = (new (route.controller as any))[route.action](req, res, next);
            if (result instanceof Promise) {
                result.then(result => result !== null && result !== undefined ? res.send(result) : undefined);
  
            } else if (result !== null && result !== undefined) {
                res.json(result);
            }
        });
    });

    if (!connection.isConnected) {
      connection = await connection.connect();
    }

  }).catch(error => console.log(error));
  

  return app;
}

//./src/routes/routes
import {DocumentController} from "../controller/DosumentsController";

export const Routes = [{
    method: "get",
    route: "/documents",
    controller: DocumentController,
    action: "all"
}, {
    method: "get",
    route: "/documents/:id",
    controller: DocumentController,
    action: "one"
}, {
    method: "post",
    route: "/documents",
    controller: DocumentController,
    action: "save"
}];

Answer 1

我实际上遇到了同样的问题，我花了很长时间才解决。问题是您需要在每次lambda调用开始时初始化数据库。在本例中，您的configureApp方法返回一个promise，在启动服务器之前不会等待它。

我不完全确定使用无服务器AWS的解决方案，但您应该能够这样做：

export const hello = async (event: any, context: Context) => {
  const app = await configureApp()
  const server = createServer(app, undefined, binaryMimeTypes);
  proxy(server, event, context);
}