[Epic] KeyValue repository

[bajtos]

So far, LB4 persistence story is all about CRUD. Key-value stores are another common scenario we should support.

LoopBack 3.x introduced KeyValue API and Redis + eXtremeScale connectors.

For LoopBack 4, we need to add Repository implementations for KeyValue API and verify that all pieces work together as expected.

Scope

• [x] Add necessary Repository APIs and implementations (#1539)
• [x] Verify the use case against real Redis instance (#1481)
• [x] CLI support (#1588)
• Docs
  • [x] Documentation (#1654)
  • [x] Example app (https://github.com/strongloop/loopback4-example-shopping/pull/4)
  • [ ] Blog post

The use case to drive the features: a "shopping cart" component used on an e-shop platform like Walmart.

[raymondfeng]

The runtime support is added - https://github.com/strongloop/loopback-next/pull/1539

[bajtos]

Please note that the runtime implementation has a flaw we need to address, preferably before considering this feature as done. See https://github.com/strongloop/loopback-next/pull/1539#discussion_r209892539:

Ideally, I'd like our DefaultKeyValueRepository to leverage the same mechanism that DefaultCrudRepository uses:

• The backing model has the same name as the LB4 model.
• If the datasource already has a backing model defined, then we reuse it.
• When defining a new backing model, LB4 property definition is converted to juggler schema.

[raymondfeng]

Adding docs - https://github.com/strongloop/loopback-next/pull/1654

[dhmlau]

The docs task has been created and PR has merged. Closing this task as resolved.