AWS Cloudfront Functions

This note was created on 2023-04-03
This note was last edited on 2023-04-03

=== Redirect apex to www ===
The following code will add www subdomain and make a redirect, preserving query string(s):
~~~
function handler(event) {
  var request = event.request;
  var target = 'https://www.' + request.headers.host.value + request.uri;

  if (Object.keys(request.querystring).length > 0) {
    target = target + '?';
    for (var key in request.querystring) {
      if (!target.endsWith('?')) {
        target = target + '&';
      }
      target = target + key + '=' + request.querystring[key].value;
    }
  }

  var response = {
    statusCode: 302,
    statusDescription: 'Found',
    headers: {
      location: {
        value: target
      }
    }
  };

  return response;
}
~~~