使用IAM角色调用AWS API Gateway

Question

我有一个API网关，我已经使用aws4库从Node.js调用了以下格式：

let aws4 = require('aws4');

let request = {
  host: 'myapi.execute-api.us-west-2.amazonaws.com',
  method: 'GET',
  url: 'https://myapi.execute-api.us-west-2.amazonaws.com/Prod/foos',
  path: '/Prod/foos'
}

let signedRequest = aws4.sign(request,
  {
    secretAccessKey: AWS.config.credentials.secretAccessKey,
    accessKeyId: AWS.config.credentials.accessKeyId
  })

delete signedRequest.headers['Host']
delete signedRequest.headers['Content-Length']

let response = await axios(signedRequest)

现在，我们要停止直接在服务器上保存凭据，而是使用IAM角色。

当我尝试不使用凭据调用它时，无论是否使用aws4对其进行签名，都会出现此错误：

The security token included in the request is invalid.