[AKS] aks-preview: bump minCliCoreVersion to 2.85.0 for ACNS performance compatibility

[FumingZhang]

Related command

az aks create, az aks update (network profile / ACNS setup path)

Description

Raise azext.minCliCoreVersion for aks-preview from 2.76.0 to 2.85.0 and bump the extension to 21.0.0b9.

Since aks-preview 20.0.0b5 (PR #9779), AKSPreviewManagedClusterContext.get_acns_enablement() returns four values (adding the ACNS performance / datapath-acceleration flag). The extension's set_up_network_profile() calls super().set_up_network_profile(), and the base acs module only started consuming that fourth value (via get_acns_enablement_with_perf()) in azure-cli core 2.85.0.

On any core older than 2.85.0, the base set_up_network_profile() still unpacks three values:

(acns_enabled, acns_observability, acns_security) = self.context.get_acns_enablement()

so every az aks create / az aks update fails with:

ValueError: too many values to unpack (expected 3)

Because the manifest advertised minCliCoreVersion = 2.76.0, the extension could be installed on incompatible cores and crashed at runtime (e.g. aks-preview 21.0.0b6 on azure-cli 2.82.0). Raising the floor makes az refuse to load the extension on an incompatible core (prompting an upgrade) instead of crashing mid-command.

• Regression introduced in: 20.0.0b5
• Minimum required core: >= 2.85.0

---

This checklist is used to make sure that common guidelines for a pull request are followed.

General Guidelines

• Have you run azdev style aks-preview locally? (pip install azdev required)
• Have you run python scripts/ci/test_index.py -q locally? (pip install azdev required)
• My extension version conforms to the Extension version schema

About Extension Publish

Only setup.py (version) and HISTORY.rst are updated for the release; src/index.json is intentionally left untouched.

[azure-client-tools-bot-prd]

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[Copilot]

Pull request overview

This PR updates the aks-preview extension release metadata to prevent runtime crashes on older Azure CLI cores by enforcing a higher minimum supported azure-cli core version.

Changes:

• Bump aks-preview extension version to 21.0.0b9.
• Raise azext.minCliCoreVersion from 2.76.0 to 2.85.0.
• Add a release note entry documenting the minimum core version change.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
src/aks-preview/setup.py	Bumps the extension package version to 21.0.0b9.
src/aks-preview/HISTORY.rst	Adds release notes for 21.0.0b9, including the new minimum CLI core requirement.
src/aks-preview/azext_aks_preview/azext_metadata.json	Raises azext.minCliCoreVersion to 2.85.0 to prevent loading on incompatible cores.

[yonzhan]

AKS