NestJS Serverless - 应用程序不断重新启动自己答案

【问题标题】：NestJS Serverless - App keeps reinitiating itselfNestJS Serverless - 应用程序不断重新启动自己
【发布时间】：2022-07-13 17:52:11
【问题描述】：

我正在尝试设置 NestJS 无服务器应用程序。该应用程序以sls offline start 开始正常运行。但问题是应用程序不断地重新启动自己。未设置缓存服务器。每次我调用端点时，服务器都会重新启动。

Lambda

import { Handler, Context } from 'aws-lambda';
import { Server } from 'http';
import { createServer, proxy } from 'aws-serverless-express';
import { eventContext } from 'aws-serverless-express/middleware';
import { NestFactory } from '@nestjs/core';
import { ExpressAdapter } from '@nestjs/platform-express';
import { AppModule } from './app.module';
import express from "express";

let cachedServer: Server;

async function bootstrapServer(): Promise<Server> {
    console.log("cached?", !!cachedServer);
    if (!cachedServer) {
        const expressApp = express();
        const nestApp = await NestFactory.create(AppModule, new ExpressAdapter(expressApp))
        nestApp.use(eventContext());
        await nestApp.init();
        
        // here is the set
        cachedServer = createServer(expressApp);
    }
    return cachedServer;
}

export const handler: Handler = async (event: any, context: Context) => {
    // here is another set
    cachedServer = await bootstrapServer();
    return proxy(cachedServer, event, context, 'PROMISE').promise;
}

输出

ANY /dev (λ: graphql)
cached? false
[Nest] 24777  - 05/29/2022, 9:00:31 AM     LOG [NestFactory] Starting Nest application... +186ms
[Nest] 24777  - 05/29/2022, 9:00:31 AM     LOG [InstanceLoader] AppModule dependencies initialized +3ms
[Nest] 24777  - 05/29/2022, 9:00:31 AM     LOG [RoutesResolver] AppController {/}: +0ms
[Nest] 24777  - 05/29/2022, 9:00:31 AM     LOG [RouterExplorer] Mapped {/, GET} route +1ms
[Nest] 24777  - 05/29/2022, 9:00:31 AM     LOG [NestApplication] Nest application successfully started +0ms
(λ: graphql) RequestId: cl3r0i9bu000b49v67zkk50gl  Duration: 12.56 ms  Billed Duration: 13 ms


ANY /dev (λ: graphql)
cached? false
[Nest] 24777  - 05/29/2022, 9:00:31 AM     LOG [NestFactory] Starting Nest application... +188ms
[Nest] 24777  - 05/29/2022, 9:00:31 AM     LOG [InstanceLoader] AppModule dependencies initialized +3ms
[Nest] 24777  - 05/29/2022, 9:00:31 AM     LOG [RoutesResolver] AppController {/}: +1ms
[Nest] 24777  - 05/29/2022, 9:00:31 AM     LOG [RouterExplorer] Mapped {/, GET} route +0ms
[Nest] 24777  - 05/29/2022, 9:00:31 AM     LOG [NestApplication] Nest application successfully started +0ms
(λ: graphql) RequestId: cl3r0i9h5000e49v65mfs21vo  Duration: 15.21 ms  Billed Duration: 16 ms

有人有什么想法吗？

【问题讨论】：

标签： nestjs serverless serverless-framework

【解决方案1】：

From the docs: serverless-offline 是一个模拟 lambda 和 api-gateway 的插件。

意思不是执行环境，它就像你每次都调用一个冷函数一样。你需要添加一个选项才能让它作为一个真正的函数工作。

sls offline start --allowCache

【讨论】：