How to extend instance pool with discover service?

[vaxilicaihouxian]

For example:
I have the etcd that manage the IP+Port of my app.
When the IP+Port offline the api-server can remove it from the instance pool.

[liuqing6767]

There is a project to do it.
We have finished the design.
One contributor submit nacos implement .

We will write a develop guide to introduce how to extend discover server in next month.
Welcome to submit PR😊

[githublaohu]

good issue。What is the difference between ECD path and value。