Extpillar nodegroups support lists

[oeko2002]

What does this PR do?

Supporting of YAML lists for the nodegroups ext_pillar

What issues does this PR fix or reference?

#55146

Previous Behavior

Nodegroups formed as YAML list

nodegroups:
  mynodegroup:
    - host1
    - host2

fail to parse as ext_pillar nodegroups, resulting in ERROR logs:

2026-05-06 12:47:54,667 [salt.utils.minions:616 ][DEBUG   ][528] Evaluating final compound matching expr: {'host1'} {'host2'} 
2026-05-06 12:47:54,668 [salt.utils.minions:621 ][ERROR   ][528] Invalid compound target: ['host1', 'host2']

New Behavior

Parsing works:

2026-05-06 12:47:55,097 [salt.utils.minions:616 ][DEBUG   ][528] Evaluating final compound matching expr: {'host1', 'host2'}
2026-05-06 12:47:55,100 [salt.utils.minions:482 ][DEBUG   ][528] minions: {'host1', 'host2'}

Merge requirements satisfied?

• Docs
• Changelog - https://docs.saltproject.io/en/master/topics/development/changelog.html
• Tests written/updated

Commits signed with GPG?

No

[welcome]

Hi there! Welcome to the Salt Community! Thank you for making your first contribution. We have a lengthy process for issues and PRs. Someone from the Core Team will follow up as soon as possible. In the meantime, here's some information that may help as you continue your Salt journey.
Please be sure to review our Code of Conduct. Also, check out some of our community resources including:

• Salt's Contributor Guide
• Join our Community Discord
• Salt Project YouTube channel
• GitHub Discussions

There are lots of ways to get involved in our community. Every month, there are around a dozen opportunities to meet with other contributors and the Salt Core team and collaborate in real time. The best way to keep track is by subscribing to the Salt Community Events Calendar.
If you have additional questions, email us at saltproject.pdl@broadcom.com. We're glad you've joined our community and look forward to doing awesome things with you!

[dwoz]

@oeko2002 This needs to go into 3006.x. I've took the liberty of changing the base branch but there are conflicts that need to be resolved.

[oeko2002]

Ok, rebased to 3006.x branch :D

[oeko2002]

Adjusted the tests

[oeko2002]

Anything I need to do?

[twangboy]

While using nodegroup_comp is the correct approach to flatten the list, modifying all_nodegroups[nodegroup_name] in-place mutates the global opts["nodegroups"] structure during the master's runtime. This can cause unexpected side effects for other parallel operations or subsequent lookups that expect the raw definition.

Suggested Change:
Assign the expanded group string to a local variable instead:

group_expr = nodegroup_comp(nodegroup_name, all_nodegroups)
_res = ckminions.check_minions(group_expr, "compound")

[twangboy]

In production, nodegroup_comp returns a compressed compound match string (e.g., L@minion1,minion2). Because of this, group_sel will never actually be a list at runtime. Forcing it into a list here (group_sel = [group_sel]) causes the test to pass green, but it masks the real string-matching behavior of the code.

Suggested Change:
Update the mock side-effect to directly evaluate the string returned by nodegroup_comp:

        def _side_effect(group_sel, t):
            # group_sel is a compound string here, not a list
            if fake_minion_id in group_sel:
                return {"minions": [fake_minion_id], "missing": []}
            return {"minions": ["another_minion_id"], "missing": []}

[twangboy]

We are no longer accepting Bugfix releases on the 3006.x branch. Please rebase this on the 3008.x branch.