uDiscovery Redesign

[stevenhartley]

Purpose

uDiscovery started out as a simple uE for service discovery, got merged with uRegistry scope, and then became a dumping ground for all kinds of stuff not related to service discovery. The widened scope resulted in APIs that no one understands how to use as well as a slew of synchronization issues between LDS/CDS.

The purpose of this issue shall be to track the requirements for building a new uDiscovery that is intention revealing and easy to use.

uDiscovery with now be used only for uE & device discovery, as a result, it will contain:

• Location
• Versions
• List of topics

NOTE: UService specific properties will no longer be part of uDiscovery but published by the service, more details will be provided in the COVESA project
 

Proposed High level APIs:

rpc FindUE(UUri) returns (UUriBatch) {} 

Lookup a uE based on the passed UAuthority and UEntity (supporting wildcards in the UUri names)
Returns a list of fully qualified UUris that includes UAuthority and UEntity information (where they are and what version they are)
FYI, this is similar to the old LookupUri() but rebranded to make more sense

rpc GetUETopics(UUri) returns (UUriBatch){} 

Given a UUri that has UAuthority and UEntity, return a list of the uE's topics in UUri format (notification & publish)

NOTE: Additional APIs could be considered later but start small and simple and we drop the Node and NodeProperties garbage