API has some inherent (from ExternalDNS upstream) poor design choices: annotation label filtering (was made to support ingress.class filtering), namespace flag (we prefer the whole cluster scope or more advanced flags) . The idea of this user story is to work upstream to enforce our line of thoughts so that we can make the operator's API cleaner.

• Acceptance Criteria
  • Label filtering is the only option  for the source filtering available to operators
  • ExternalDNS can watch for endpoints from all namespaces only

• Tasks:
  • ExternalDNS upstream. Add label filtering for all sources.
  • Operator. Change API/code to use label filter for all sources.
  • Operator. Remove namespace API for the source
  • Make sure Kohl's feedback is integrated into API (tracked by NE-676)
  • Review the API with David Eads again (last step)

• Open questions:
  • Log level
  • Synchronization interval 
  • Sync policy (for future - out of scope for this release)