如何在使用express.static时不在aws-lambda和aws-sam中的express中返回json

Question

我正在使用aws lambda和aws中的sma-cli工具创建一个无服务器网站(主要是为了测试对api的真实请求(。我想使用express.static函数为资产提供服务，但遇到问题。当我使用它时，我收到一个错误，说它没有返回json，错误说它需要这样做才能工作。我现在有两个函数：视图(为ejs文件服务(和资产(为css和frontendjs等静态文件服务(。这是我的模板。yml:

# This is the SAM template that represents the architecture of your serverless application
# https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/serverless-sam-template-basics.html
# The AWSTemplateFormatVersion identifies the capabilities of the template
# https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/format-version-structure.html
AWSTemplateFormatVersion: 2010-09-09
Description: >-
[Description goes here]
# Transform section specifies one or more macros that AWS CloudFormation uses to process your template
# https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/transform-section-structure.html
Transform:
- AWS::Serverless-2016-10-31
# Resources declares the AWS resources that you want to include in the stack
# https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/resources-section-structure.html
Resources:
assets:
Type: AWS::Serverless::Function
Properties:
Handler: amplify/backend/function/assets/src/index.handler
Runtime: nodejs14.x
MemorySize: 512
Timeout: 100
Description: serves the assets
Events:
Api:
Type: Api
Properties:
Path: /assets/{folder}/{file}
Method: GET
views:
Type: AWS::Serverless::Function
Properties:
Handler: amplify/backend/function/views/src/index.handler
Runtime: nodejs14.x
MemorySize: 512
Timeout: 100
Description: serves the views
Events:
Api:
Type: Api
Properties:
Path: /
Method: GET
Outputs:
WebEndpoint:
Description: "API Gateway endpoint URL for Prod stage"
Value: !Sub "https://${ServerlessRestApi}.execute-api.${AWS::Region}.amazonaws.com/Prod/"

我的资产函数代码：index.js:

const awsServerlessExpress = require('aws-serverless-express');
const app = require('./app');
const server = awsServerlessExpress.createServer(app);
exports.handler = (event, context) => {
console.log(`EVENT: ${JSON.stringify(event)}`);
return awsServerlessExpress.proxy(server, event, context, 'PROMISE').promise;
};

app.js:

const express = require('express'),
app = express()
app.use(express.json())
app.use('/assets', express.static('assets'))
app.listen(3000);
module.exports = app

template.yml是否有一些我应该知道的配置选项，或者我是否必须更改代码？

Answer 1

我在nodejs中用fs创建了自己的解决方案。我在视图函数中做了一个简单的代码集：

app.get('/assets/*', (req, res) => {
if (!fs.existsSync(__dirname + `/${req.url}`)) {
res.sendStatus(404).send(`CANNOT GET ${req.url}`);
return;
}
res.send(fs.readFileSync(__dirname + `/${req.url}`, 'utf-8'));
})

我还编辑了template.yml，使其成为/assets/{folder}/{file}路径的api用于视图函数，并删除了assets函数，将包含所有资产的assets文件夹移动到视图函数dir

编辑：对于一些resson来说，几乎所有的内容类型http头都总是设置为text/html，但将代码修改为这样可以修复它：

app.get('/assets/*', (req, res) => {
if (!fs.existsSync(`${__dirname}${req.url}`)) {
res.sendStatus(404).send(`CANNOT GET ${req.url}`);
return;
}
res.contentType(path.basename(req.url))
res.send(fs.readFileSync(__dirname + `${req.url}`, 'utf-8'));
})

所做的只是在res对象上使用contentType函数。您只需输入文件的名称，它就会自动找到正确的内容类型。