Cloud Function - CloudFront Cache poisoning prevention

cache-poisoning-prevention

function handler(event) {
  var request = event.request;
  var allowed = ["accept", "accept-encoding", "if-none-match", "if-modified-since", "user-agent", "range"];
  var sanitized = {};
  for (var h in request.headers) {
    if (allowed.indexOf(h) !== -1) sanitized[h] = request.headers[h];
  }
  request.headers = sanitized;
  request.uri = request.uri.replace(/\/+/g, "/");
  return request;
}