Actors v1/v2 Interface

[DeepanshuA]

Description

Adding an initial draft of v2 version of Placement/Actors Service Interface.
Still need to update Makefile to generate protos from a v2 version.
Still need to update helm charts to load appropriate service and corresponding component, if associated with the Control Plane Service.

Issue reference

Please reference the issue this PR will close: #[issue number]

Checklist

Please make sure you've completed the relevant tasks for this PR, out of the following list:

• Code compiles correctly
• Created/updated tests
• Unit tests passing
• End-to-end tests passing
• Extended the documentation / Created issue in the https://github.com/dapr/docs/ repo: dapr/docs#[issue number]
• Specification has been updated / Created issue in the https://github.com/dapr/docs/ repo: dapr/docs#[issue number]
• Provided sample for the feature / Created issue in the https://github.com/dapr/docs/ repo: dapr/docs#[issue number]

[ItalyPaleAle]

Thanks for doing this. However, we don't need an interface for a proto service, as that will be implementation-dependent.

We just need to expand the existing interfaces in pkg/actors/internals for placement and reminders.

[DeepanshuA]

Thanks for doing this. However, we don't need an interface for a proto service, as that will be implementation-dependent.

We just need to expand the existing interfaces in pkg/actors/internals for placement and reminders.

As LookupActor etc. calls would be now handled by a separate service, won't we require RPCs for those?
My understanding is that we would need a new v2 service in vNext version of Dapr, catering to v1 and v2 of Placement/Actor Service.

[ItalyPaleAle]

Yes we will need RPCs but I think those should not be exposed to Dapr. Because different implementations will need separate stuff: for example, Placement in v1 is "push-based" (disseminates data ahead of time), while in v2 it's "pull-based" (responds to queries on demand).

Let's chat tomorrow, I'll show you what I think!