fix: add ACL-specific butane config with first-boot service workaround

[aadhar-agarwal]

What this PR does / why we need it:

• Adds an ACL-specific Butane config (acl.yml) with explicit storage.links symlinks for the ignition-bootcmds and ignition-file-extract services into sysinit.target.wants.

• Reorder nodecustomdata.yml conditionals to check IsACL before IsAzlOSGuard

  • ACL uses CustomizedImageLinuxGuard for BYOI image testing, so IsAzlOSGuard also matches ACL nodes. Check IsACL first to avoid using OSGuard provisioning scripts, which are incompatible with ACL. To fix this, the goal is to end up using CustomizedImageTrustedLaunch to test BYOI images - Need to enable this in aks-rp

Why: On ACL, machine-id is empty (not absent) after VHD build. systemd only triggers ConditionFirstBoot=yes when machine-id is missing, so enabled services don't start on first boot. On Flatcar, waagent's CoreOS deprovisioning removes machine-id entirely, avoiding this issue. The explicit symlinks ensure these services start regardless of first-boot stat

Testing

• [TEST All VHDs] AKS Linux VHD Build - Msft Tenant

• Vendored this changed into aks-rp to run AKS E2Es

Which issue(s) this PR fixes:

Fixes #

[Copilot]

Pull request overview

This PR adds an ACL (Azure Container Linux) specific Butane template to ensure first-boot systemd services run correctly when /etc/machine-id is left empty after VHD build, and updates the Flatcar/ACL Ignition generation path to select the appropriate template. It also reorders nodecustomdata.yml conditionals so ACL nodes don’t incorrectly take the AzlOSGuard path when both match.

Changes:

• Add parts/linux/cloud-init/acl.yml with ACL-specific systemd enablement symlink workaround.
• Parameterize cloudInitToButane() to accept a Butane YAML path and select ACL vs Flatcar template based on config.IsACL().
• Reorder nodecustomdata.yml conditionals to check IsACL before IsAzlOSGuard.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
pkg/agent/const.go	Adds a constant for the ACL Butane template path (linux/cloud-init/acl.yml).
pkg/agent/baker.go	Parameterizes Butane conversion and selects ACL vs Flatcar Butane template when generating Ignition customData.
pkg/agent/baker_test.go	Updates tests to pass the Flatcar Butane template path into cloudInitToButane.
parts/linux/cloud-init/nodecustomdata.yml	Reorders templating conditionals so ACL uses ACL-specific provisioning scripts instead of AzlOSGuard ones.
parts/linux/cloud-init/acl.yml	Introduces ACL-specific Butane config with explicit sysinit.target.wants symlinks.

[Copilot]

Pull request overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.