feat(controller): support serverless serving with keda support by k8s scale subresource.

[X1aoZEOuO]

What this PR does / why we need it

Detailed Explanation of Commit

This commit introduces a guide for configuring serverless environments on Kubernetes, focusing on integrating Prometheus for monitoring and KEDA for autoscaling. The guide aims to optimize resource efficiency through event-driven scaling while maintaining observability for AI/ML workloads.

• Prometheus Integration: Configured with namespaceSelector for cross-namespace monitoring
• KEDA Autoscaling: Custom metric scaling with Prometheus triggers
• Scale-to-Zero: Activator pattern with request buffering and CloudEvents

Which issue(s) this PR fixes

Fixes #

Special notes for your reviewer

Does this PR introduce a user-facing change?

cc @pacoxu @kerthcet

[X1aoZEOuO]

/kind feature

[X1aoZEOuO]

@pacoxu @googs1025 @carlory @kerthcet Hello all! Could you spare a few minutes to review my PRs when you have a chance?

Other ref PRs:

• doc: add serverless doc with keda and activator. #499
• feat(controller): support serverless serving with 0-1 activator. #498

[pacoxu]

/assign
I will take a look this week or early next week.

[X1aoZEOuO]

@pacoxu @kenwoodjw Friendly ping, do you have some time to take a look at my PRs? Thanks a lot for your assistance!

[kerthcet]

/assign

[kerthcet]

seems some docs are duplicated with https://github.com/InftyAI/llmaz/pull/499/files, can we just put one here and refer to it in another one.

[X1aoZEOuO]

seems some docs are duplicated with https://github.com/InftyAI/llmaz/pull/499/files, can we just put one here and refer to it in another one.

@kerthcet Thank you for catching this! I've refactored the documentation structure to eliminate duplication, Now focuses specifically, and reference link to the main serverless documentation (PR #499)

[kerthcet]

The test is always failing ...

[pacoxu]

/retest

[X1aoZEOuO]

@pacoxu I have resolved the conflict. :)

[X1aoZEOuO]

/retest