Setting up all kinds of domain redirects in S3 and CloudFront http://blog.chrisdpeters.com/domain-redirects-s3-and-cloudfront/

index.js

'use strict';

exports.handler = (event, context, callback) => {
  const request = event.Records[0].cf.request;
  let uri = request.uri ? request.uri : '/';
  
  if (request.querystring) {
    uri += '?' + request.querystring;
  }
  
  const redirectTo = 'https://www.example.com/de' + uri;

  callback(null, {
    status: '301',
    statusDescription: 'Moved Permanently',
    headers: {
      location: [{
        key: 'Location',
        value: redirectTo,
      }]
    }
  });
};

redirects.xml

<RoutingRules>
  <RoutingRule>
    <Condition>
      <KeyPrefixEquals/>
    </Condition>
    <Redirect>
      <Protocol>https</Protocol>
      <HostName>www.example.org</HostName>
      <ReplaceKeyWith></ReplaceKeyWith>
    </Redirect>
  </RoutingRule>
</RoutingRules>