Support named placements in GKE node pools

[arajmane-g]

About the Module Improvement

Toolkit users will be able to utilise named compact placement policy in their node pools when deploying GKE clusters.

Implementation

Introduce a new setting placement_policy by deprecating compact_placement. type and name are two nested settings. The latter is optional.

Placement policy is assumed to exist.

Testing

Integration test will be added as a follow-up.

Following things were tested from the dev environment:

• Not setting either of the settings should not include the relevant block in the generated plan
• Setting compact_placement should fail at the Terraform plan stage with a message indicating deprecation
• It was verified that named, unnamed compact placement policies work using the new setting
• Terraform apply should fail for an unknown policy
• Terraform apply should succeed for a known compact placement policy. It was verified that the policy is attached to the VMs in the provisioned node pool

Submission Checklist

Please take the following actions before submitting this pull request.

• [x] Fork your PR branch from the Toolkit "develop" branch (not main)
• [x] Test all changes with pre-commit in a local branch #
• [x] Confirm that "make tests" passes all tests
• [x] Add or modify unit tests to cover code changes: not applicable
• [x] Ensure that unit test coverage remains above 80%: not applicable
• [x] Update all applicable documentation
• [x] Follow Cluster Toolkit Contribution guidelines #