无法使用无服务器框架和 TypeScript 从 Lambda 层导入模块

Question

我的无服务器应用程序中有多个功能。其中两个用于 REST 端点，一个是 SQS 处理程序。他们都使用相同的库。因此，我想将它们移至 Lambda Layer 并跨函数共享以减小大小。

我正在使用 Serverless Framework 2.46、TypeScript 4.3 和 NodeJS 14。我有以下项目结构：

/
 - layers/
   - nodejs/
     - node_modules/
     - package.json
 - src/
   - handlers/ - here are my handlers 
   - etc...

我已将 TypeScript 配置为从图层文件夹导入库，如下所示import middy from '/opt/nodejs/@middy/core';。这是我的 tsconfig

{
  "compilerOptions": {
    "preserveConstEnums": true,
    "strictNullChecks": true,
    "sourceMap": true,
    "allowJs": false,
    "target": "ES2020",
    "module": "CommonJS",
    "outDir": ".build",
    "moduleResolution": "node",
    "esModuleInterop": true,
    "resolveJsonModule": true,
    "experimentalDecorators": true,
    "emitDecoratorMetadata": true,
    "lib": [
      "ES6",
      "ES2019",
      "ES2020"
    ],
    "baseUrl": ".",
    "paths": {
      "/opt/nodejs/*": [
        "layers/nodejs/node_modules/*"
      ]
    }
  },
  "exclude": [
    "node_modules",
    "opt/nodejs/node_modules"
  ]
}

并有像这样的无服务器配置

service: my_serverless-app
frameworkVersion: '2'
useDotenv: true
variablesResolutionMode: 20210326
configValidationMode: error

custom:
  stage: ${opt:stage, self:provider.stage}
  dbHost:
    local: ${env:DB_HOST, ''}
    dev: ${ssm:DB_HOST_DEV}

  dbPort:
    local: ${env:DB_PORT, ''}
    dev: ${ssm:DB_PORT_DEV}

  dbUser:
    local: ${env:DB_USER, ''}
    dev: ${ssm:DB_USER_DEV}

  dbPassword:
    local: ${env:DB_PASSWORD, ''}
    dev: ${ssm:DB_PASSWORD_DEV}

  dbName:
    local: ${env:DB_NAME, ''}
    dev: ${ssm:DB_NAME_DEV}

provider:
  name: aws
  region: us-east-1
  stage: dev
  runtime: nodejs14.x
  lambdaHashingVersion: 20201221
  environment:
    NODE_PATH: "./:opt/nodejs/node_modules"
    DB_HOST: ${self:custom.dbHost.${self:custom.stage}}
    DB_PORT: ${self:custom.dbPort.${self:custom.stage}}
    DB_USER: ${self:custom.dbUser.${self:custom.stage}}
    DB_PASSWORD: ${self:custom.dbPassword.${self:custom.stage}}
    DB_NAME: ${self:custom.dbName.${self:custom.stage}}

plugins:
  - serverless-plugin-typescript
  - serverless-offline

functions:
  getLedgerRecords:
    handler: src/handlers/ledger.ledgerRecords
    events:
      - http:
          path: /ledger-records
          method: get
    layers:
      - { Ref: CommonLibsLambdaLayer }

  getLedgerRecord:
    handler: src/handlers/ledger.ledgerRecord
    events:
      - http:
          path: /ledger-records/{id}
          method: get
    layers:
      - { Ref: CommonLibsLambdaLayer }

layers:
  CommonLibs:
    path: layers/nodejs
    description: "Common dependencies"
    compatibleRuntimes:
      - nodejs14.x

当我通过命令在本地运行应用程序时，serverless offline --stage local没有错误，但是当我执行 REST 端点（或任何其他端点）时，出现以下错误：

[offline] Loading handler... (D:\Projects\services\.build\src\handlers\ledger)
[offline] _____ HANDLER RESOLVED _____
offline: Failure: Cannot find module '/opt/nodejs/@middy/core'
Require stack:
- D:\Projects\services\.build\src\handlers\ledger.js
- D:\Projects\services\node_modules\serverless-offline\dist\lambda\handler-runner\in-process-runner\InProcessRunner.js
- D:\Projects\services\node_modules\serverless-offline\dist\lambda\handler-runner\in-process-runner\index.js
- D:\Projects\services\node_modules\serverless-offline\dist\lambda\handler-runner\HandlerRunner.js
- D:\Projects\services\node_modules\serverless-offline\dist\lambda\handler-runner\index.js
- D:\Projects\services\node_modules\serverless-offline\dist\lambda\LambdaFunction.js
- D:\Projects\services\node_modules\serverless-offline\dist\lambda\LambdaFunctionPool.js
- D:\Projects\services\node_modules\serverless-offline\dist\lambda\Lambda.js
- D:\Projects\services\node_modules\serverless-offline\dist\lambda\index.js
- D:\Projects\services\node_modules\serverless-offline\dist\ServerlessOffline.js
- D:\Projects\services\node_modules\serverless-offline\dist\index.js
- D:\Projects\services\node_modules\serverless-offline\dist\main.js
- D:\Projects\services\node_modules\serverless\lib\classes\PluginManager.js
- D:\Projects\services\node_modules\serverless\lib\Serverless.js
- D:\Projects\services\node_modules\serverless\scripts\serverless.js
- D:\Projects\services\node_modules\serverless\bin\serverless.js

另外，当我尝试部署应用程序时，我遇到了同样的问题。我究竟做错了什么？请给我一个链接，获取如何正确配置 lambda 层的教程。提前致谢！

Answer 1

从无服务器框架和 TypeScript 的角度来看，您的层配置是正确的。

问题可能出在项目本身的打包上（例如内部serverless-plugin-typescript）

我建议尝试另一个 TypeScript 插件，比如serverless-esbuild

使用您的tsconfig.json示例和示例serverless.yml。我在这里创建了一个例子：

https://github.com/oieduardorabelo/2021-07-21-serverless-typescript-layers

它使用 esbuild 来打包 TypeScript 并将其转换为 JavaScript，并且按预期工作