A DNS server suitable for testing. Records can be updated via HTTP requests. Missing records are resolved using the system resolver. This is distinct in behaviour from Let's Encrypt's challtestsrv which has a notion of a default response, which would not be suitable for general DNS usage.
The following are Examples of HTTP requests that the server supports:
GET /
GET /v1/a/www.google.com
PUT /v1/a/www.google.com?v=127.0.0.1
DELETE /v1/a/www.google.com