Refactor the SyncTrigger extensions payload to make it generic

[TsuyoshiUshio]

What problem would the feature you're requesting solve? Please describe.

Currently as a tactical solution for LIMA scenarios, FunctionsSyncManager is adding the extensions portion of host.json to the sync triggers payload only for Kubernetes environments. We want to remove that restriction so it's applied in other environments as well, which will allow us to address #5390 in a general manner.

For more details see the discussion in : #7386

CC: @pragnagopa @mathewc @cgillum

Describe the solution you'd like

Make the extensions payload to generic so it's always returned, not based on sku/environment. We'll need to update the minimal response that is returned when the full payload { triggers: [], functions: [], extensions: {}, secrets: {} } is over the size limit. The new minimal format will be { triggers: [], extensions: {} }. This way, consumers can rely on host level extensions config in addition to the functions config already included in the triggers data.

Describe alternatives you've considered

We can keep it only available for Kubernetes Environment, However, Container usage for the AppService will be the same.

Additional context

We considered the PR #7386 as hot fix. We need to refactor and add proper test for the generic usage.

[pragnagopa]

@TsuyoshiUshio - would you like to address this sometime in future as you have most context?

[TsuyoshiUshio]

@pragnagopa Yes. absolutely.

[pragnagopa]

cc @mathewc

@TsuyoshiUshio - Please address comments - #7386 (comment) as well as part of this fix.

[fabiocav]

@TsuyoshiUshio are you planning on working on this item as part of spring 103? Can we have a quick sync on this to talk about the proposed solution?

[mathewc]

Yes - before anything is checked in for this, I need to review. The general goals for this are captured in #5390.

[TsuyoshiUshio]

Not for todays deployment. I'd happy to discuss the design first! It should requires careful testing.

[TsuyoshiUshio]

I'd like to know the counter microservices spec at first. I mean I'd like to research the pattern How the SyncTrigger Payload is used. I know the usage of Kubernetes environment with KuduLite, However, I don't know about the other use cases. Do you know the pointer?

[fabiocav]

@TsuyoshiUshio moving this to the triaged milestone until we have a chance to discuss.

[pragnagopa]

Tagging @chiangvincent and @cachai2 - this needed for Scale Controller changes - Target Based Scaling feature

[pragnagopa]

Tagging @mathewc - as FYI for discussions and review

[fabiocav]

Is there a proposed design for this? Can we sync on a design prior to having this assigned to a sprint?

[kashimiz]

Marking this as in-progress as a PR by Tsuyoshi is under review: #7863

[TsuyoshiUshio]

We decide to create a separate API admin/host/extensions/config for fetching the host.json with AppSertings/default value.
I'm going to share the Pull Request.