Document custom readiness endpoint for scale from zero

[welteki]

Description

Note on the Scale to Zero and Auto-scaling pages that some workloads may
need a custom readiness endpoint when scaling from zero.

Motivation and Context

Slow-starting functions may need a custom readiness endpoint so the
gateway only sends traffic once the function is fully ready. This wasn't
mentioned in the docs.

• I have raised an issue to propose this change (required)

How Has This Been Tested?

Checked the rendered Markdown and verified links.

Types of changes

• New feature (non-breaking change which adds functionality)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I've read the CONTRIBUTION guide
• I have signed-off my commits with git commit -s

[reviewfn]

AI Pull Request Overview

Disclaimer: This review was generated by automated AI and may contain errors. Do not trust its outputs without human verification.

Summary

• Documentation-only PR covering scale-from-zero readiness guidance.
• Adds guidance to both autoscaling architecture and OpenFaaS Pro scale-to-zero pages.
• Links to the existing custom HTTP health checks reference section.
• The internal anchor resolves to docs/reference/workloads.md.
• No blocking correctness, rendering, or publish-quality issues found in the scoped changes.

Approval rating (1-10)

8/10. The additions are accurate, scoped, and useful; no blocking issues found.

Summary per file

Summary per file

File path	Summary
docs/architecture/autoscaling.md	Adds scale-from-zero readiness guidance to autoscaling FAQ.
docs/openfaas-pro/scale-to-zero.md	Adds readiness endpoint guidance to scale-to-zero usage docs.

Overall Assessment

The PR adds focused documentation for a real scale-from-zero failure mode: functions whose process starts before the workload can safely serve traffic. The new guidance is consistent with the existing workload reference, uses the correct com.openfaas.ready.http.* annotation prefix, and links to the relevant reference material. I did not find blocking issues in the scoped documentation changes.

Detailed Review

Detailed Review

Content review

No blocking findings.

• Title and excerpt fit are not affected by this PR; the new content fits the existing scale-to-zero and autoscaling page purposes.
• The opening thesis of the added text is clear: default readiness may be insufficient for slow-starting functions, so a custom endpoint may be needed.
• The examples are concrete enough for readers to identify affected workloads, and the linked reference provides the implementation-level annotation list.
• The internal link target /reference/workloads#custom-http-health-checks matches the existing ### Custom HTTP health checks heading in docs/reference/workloads.md.

AI agent details.

Agent processing time: 1m12.39s
Environment preparation time: 10.61s
Total time from webhook: 1m32.456s