Missing docs on `load_balancing_scheme` for compute_forwarding_rule

[wyardley]

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Terraform Version & Provider Version(s)

Terraform v1.11.3
on darwin_arm64
+ provider registry.terraform.io/hashicorp/google v6.27.0
+ provider registry.terraform.io/hashicorp/google-beta v6.27.0
+ provider registry.terraform.io/hashicorp/null v3.2.3
+ provider registry.terraform.io/hashicorp/random v3.7.1

Affected Resource(s)

• google_compute_forwarding_rule

Terraform Configuration

resource "google_compute_forwarding_rule" "foo" {
  name                    = "foo"
  region                  = "us-central1"
  network                 = "foo"
  ip_address              = google_compute_address.xyz.self_link
  load_balancing_scheme   = ""
  target                  = data.google_sql_database_instance.xyz.psc_service_attachment_link
  allow_psc_global_access = true
}

Debug Output

No response

Expected Behavior

All resource attributes to be documented.

Actual Behavior

https://registry.terraform.io/providers/hashicorp/google/latest/docs/resources/compute_forwarding_rule contains examples of load_balancing_scheme being set for google_compute_forwarding_rule, but doesn't appear to list it among the resource attributes that can be set.

Looking through https://github.com/GoogleCloudPlatform/magic-modules/blob/main/mmv1/products/compute/ForwardingRule.yaml, I don't see it, but seems like it's coming from
https://github.com/GoogleCloudPlatform/magic-modules/blob/4a72b591b882645a803c578c097096c694eb9687/mmv1/third_party/cai2hcl/services/compute/compute_forwarding_rule.go#L107

The docs also appear to be generated, so I'm not sure how to make a fix for the docs.

There seem to be some valid uses for setting this to an empty string, but I don't find a lot of docs on this. It appears to be possible to set the scheme to "" (however, somewhat unexpectedly, omitting the empty string or setting it to null causes it to get set to EXTERNAL).

Steps to reproduce

Important Factoids

No response

References

• Document the Forwarding Rule Usage for PSC #12326
• Update documentation of forwarding rule for vpc psc endpoint GoogleCloudPlatform/magic-modules#6864

[SirGitsalot]

Is this what you're looking for? FWIW, the Magic Modules YAML config uses camel case names, so you'd need to look for loadBalancingScheme.

The weirdness with the difference between an empty string, null, and omitting the field is due to the different ways that Terraform and Google APIs handle them (e.g., on the Terraform side omitted and empty are distinct values, on the API side they're treated equivalently). For load_balancing_scheme in particular, this means TPG can know when its null or omitted that the field gets the default EXTERNAL but TPG leaves the empty string value up to the API to decide how to handle it.

[wyardley]

@SirGitsalot thanks! Three things

1. I see it now that I got to that anchor. Doing a text search for load_balancing_scheme on the page somehow hadn't semed to work for me before in either Firefox or Chrome, but I can see that it's there now. Maybe I just didn't get through all the examples?
2. The ordering of parameters within the docs seems also pretty haphazard -- I did scroll up through most of those sections.
3. I think the empty string variant is also not documented as an available option for that enum?

Familiar with the magic modules YAML config, and I thought I looked for the camelcase variant, but sorry if I missed it.

Thanks for the pointers, not sure how I missed either... I'll make a PR to include some docs on the empty string value.

[wyardley]

Is there a way to have the auto-generated docs have a note about empty string being valid, or would I just have to add some text about it?

[wyardley]

Also, IMO, it's still very confusing / suboptimal to have null at the TPG level result in the default value ("EXTERNAL"), though I do understand the reasons why it behaves this way.