Lambda\@Edge

Lambda@Edge 是 Amazon Web Services 提供的无服务器（serverless）平台。它允许你在 Amazon CloudFront 的边缘节点运行 Lambda 函数，从而可以自定义 HTTP 请求/响应的行为。

Hono 支持在 Node.js 18+ 环境下运行于 Lambda\@Edge。

1. 设置

在 Lambda\@Edge 上创建应用时，可以使用 CDK 来配置 CloudFront、IAM Role、API Gateway 等资源。

使用 cdk CLI 初始化项目。

npm

mkdir my-app
cd my-app
cdk init app -l typescript
npm i hono
mkdir lambda

yarn

mkdir my-app
cd my-app
cdk init app -l typescript
yarn add hono
mkdir lambda

pnpm

mkdir my-app
cd my-app
cdk init app -l typescript
pnpm add hono
mkdir lambda

bun

mkdir my-app
cd my-app
cdk init app -l typescript
bun add hono
mkdir lambda

2. Hello World

编辑 lambda/index_edge.ts：

import { Hono } from 'hono'
import { handle } from 'hono/lambda-edge'
const app = new Hono()
app.get('/', (c) => c.text('Hello Hono on Lambda@Edge!'))
export const handler = handle(app)

3. 部署

编辑 bin/my-app.ts：

#!/usr/bin/env node
import 'source-map-support/register'
import * as cdk from 'aws-cdk-lib'
import { MyAppStack } from '../lib/my-app-stack'
const app = new cdk.App()
new MyAppStack(app, 'MyAppStack', {
  env: {
    account: process.env.CDK_DEFAULT_ACCOUNT,
    region: 'us-east-1',
  },
})

编辑 lambda/cdk-stack.ts：

import { Construct } from 'constructs'
import * as cdk from 'aws-cdk-lib'
import * as cloudfront from 'aws-cdk-lib/aws-cloudfront'
import * as origins from 'aws-cdk-lib/aws-cloudfront-origins'
import * as lambda from 'aws-cdk-lib/aws-lambda'
import { NodejsFunction } from 'aws-cdk-lib/aws-lambda-nodejs'
import * as s3 from 'aws-cdk-lib/aws-s3'
export class MyAppStack extends cdk.Stack {
  public readonly edgeFn: lambda.Function
  constructor(scope: Construct, id: string, props?: cdk.StackProps) {
    super(scope, id, props)
    const edgeFn = new NodejsFunction(this, 'edgeViewer', {
      entry: 'lambda/index_edge.ts',
      handler: 'handler',
      runtime: lambda.Runtime.NODEJS_20_X,
    })
    // 上传任意 HTML 文件
    const originBucket = new s3.Bucket(this, 'originBucket')
    new cloudfront.Distribution(this, 'Cdn', {
      defaultBehavior: {
        origin: new origins.S3Origin(originBucket),
        edgeLambdas: [
          {
            functionVersion: edgeFn.currentVersion,
            eventType: cloudfront.LambdaEdgeEventType.VIEWER_REQUEST,
          },
        ],
      },
    })
  }
}

最后运行以下命令进行部署：

cdk deploy

Callback

如果你想添加 Basic Auth，并在验证后继续处理请求，可以使用 c.env.callback()。

import { Hono } from 'hono'
import { basicAuth } from 'hono/basic-auth'
import type { Callback, CloudFrontRequest } from 'hono/lambda-edge'
import { handle } from 'hono/lambda-edge'
type Bindings = {
  callback: Callback
  request: CloudFrontRequest
}
const app = new Hono<{ Bindings: Bindings }>()
app.get(
  '*',
  basicAuth({
    username: 'hono',
    password: 'acoolproject',
  })
)
app.get('/', async (c, next) => {
  await next()
  c.env.callback(null, c.env.request)
})
export const handler = handle(app)