Idea – [Micro] Services Registry as a Service

I’m taking a Node.js microservices course to stay up-to-date. This course is going through the process of building a service registry before going into microservices.

It occurs to me, why are we re-building a service registry for every app? Why is there not a Server Registry as a Service? I.E. Why not a “domain name service” for [micro]services so I can simply query the DNS for a given key/identifier to get the IP/port/args for the microservice.

Am I missing something? Has this been done before and I’m simply unaware of it?

Bottom line, imagine this:

• Microservice when started up, registers itself with the central registry service.
• On a regular basis (10 seconds, 30 seconds, 5 mins, etc) the microservices sends a heartbeat.
• Other microservices and components can query services by API key and service name.
  • On top of that it might be worth allowing additional arguments, like environment (dev/staging/prod) so it becomes even easier to have microservices/data mirrored for dev and production.

I certainly feel like a service/SaaS like this would handle some initial setup and make it easier to share microservices between many developers.