feat: support enabling default compute class in cluster autoscaler

[romancin]

This PR enables Default Compute Class support for Cluster Autoscaler.

[apeabody]

Thanks for the contribution @romancin!

Please resolve the linter error:

╷
│ Error: Unsupported argument
│ 
│   on ../../modules/beta-private-cluster/cluster.tf line 179, in resource "google_container_cluster" "primary":
│  179:     default_compute_class_enabled = lookup(var.cluster_autoscaling, "enable_default_compute_class", false)
│ 
│ An argument named "default_compute_class_enabled" is not expected here.

[romancin]

Thanks for the contribution @romancin!

Please resolve the linter error:

╷
│ Error: Unsupported argument
│ 
│   on ../../modules/beta-private-cluster/cluster.tf line 179, in resource "google_container_cluster" "primary":
│  179:     default_compute_class_enabled = lookup(var.cluster_autoscaling, "enable_default_compute_class", false)
│ 
│ An argument named "default_compute_class_enabled" is not expected here.

Which google provider version is the linter using? Because this argument is available only since v7.

[apeabody]

Thanks for the contribution @romancin!
Please resolve the linter error:

╷
│ Error: Unsupported argument
│ 
│   on ../../modules/beta-private-cluster/cluster.tf line 179, in resource "google_container_cluster" "primary":
│  179:     default_compute_class_enabled = lookup(var.cluster_autoscaling, "enable_default_compute_class", false)
│ 
│ An argument named "default_compute_class_enabled" is not expected here.

Which google provider version is the linter using? Because this argument is available only since v7.

Got it - It's not the linter per say, but all the relevant versions constraints in the Terraform code as the highest allowed is selected. In this case it's the most recent v6.x.

I recommend you start by bumping the relevant minimum versions in https://github.com/terraform-google-modules/terraform-google-kubernetes-engine/blob/main/autogen/main/versions.tf.tmpl#L27, as that will more clearly illustrate the dependencies. I know at a minimum we are waiting on #2456 for some examples.

[apeabody]

Thanks for the contribution @romancin!

The code base is now TPGv7 compatible, and initial support was added in #2434. However this implementation might be preferable?