Saved objects service - Phase 1

[rhoboat]

Let's release the first iteration of the saved objects system (on the new platform) as a core Kibana service that:

• exposes a Saved Objects Client as it works today
• allows a plugin to replace the Saved Objects Client
  • probably via a register-new-Client-factory method
  • supports Spaces

Once the bare service is written, we will push it up as a Feature Branch on Kibana for everyone to follow until it merges with master.

Since this looks a lot like the existing functionality in the legacy platform, what are the benefits of doing this work at all?

• API Clarity. In the new platform, we'll have better support for changes to the saved objects client.
• Core Service Responsibility. A great benefit of this work is the need to explore interactions between the Elasticsearch Service, Http Service, and Saved Object Service. By tackling this problem in the nascent stages of the new platform effort, we can set the stage for clearer boundaries and responsibilities for these core services.

Meta: #18842

• Basic Elasticsearch Service in the new platform [server] Elasticsearch service #18841
• Mappings [Saved Objects] Create mappings lib within core/server/saved_objects #21093
• Saved object legacy code in typescript
• New saved object service wired into core
• Wire into http service
• Update legacy usage of saved objects to new service

[tsullivan]

Would this effectively provide an API that the public can use for managing saved objects? For example, importing saved object backups in an automated way?

[rhoboat]

Phase 1 is just trying to get the same API into the new platform. @tsullivan