Support lb:// url in FeingClient annotation

Current behaviour

In a project where is used spring cloud gateway, feign client (with target put in configuration), we ended up having feign clients declared as follows

@FeignClient(name="${service.name:any-name}", url="${service.direct-url:}")

With configuration as follows

service:
   name: service-id
   # url: http://direct-url (only used when service discovery is not available)

This way we are able, by configuration, to either run in service discovery/load balancing mode and direct mode.

Proposal

I kind of like the way spring cloud gateway handle that by allowing lb:// protocol. Allowing this protocol in url attribute would allow the following implementation

@FeignClient(name="technical-name", url="${service.uri}")

with following configuration

service:
   uri: "lb://service-id" # or "http//direct-url"

this way it will let common behaviour, allowing to have a common behaviour in url specification.

I spotted the code responsible for feign client building and think that it would be easily doable by

• only appending http:// if url attribute value does not match the [a-z]+://.* pattern
• remove load balancing client if and only if url attribute does not starts with lb://

I am eager to implement it if you allow me to do so. I am also pleased to discuss about it and about any alternative I missed.

Thank you