Add name overrides for Internal and External Load Balancers

[cvanwijck-hub24]

When developing IaC for existing infrastructure and attempting to achieve parity between the two, the current naming assignments of multiple modules in CFF causes issues.

For example in net-lb-ext the name of the load balancer added additional items to the name if a forwarding_rules_config was passed.

name = (
  each.key == "" ? var.name : "${var.name}-${each.key}"
)

This can cause issues where a specific name is preferred, such as when bringing existing infrastructure under the control of IaC. Changing the name of a load balancer, backend service or health check would cause them to be replaced by Terraform.

This is also relevant to #2419 where peerings have a name set by combining the local and peering network names with a prefix. A similar override_name variable would resolve this issue.

Adding an optional override_name variable allows the user to specify a name if the generated name is not helpful for their use case. For users who would like to use the module as before and have names generated as before, leaving the override_name as null will use the default name assignment.

---

Checklist

I acknowledge that I have:

• Read the contributing guide
• Ran terraform fmt on all modified files
• Regenerated the relevant README.md files using tools/tfdoc.py
• Made sure all relevant tests pass

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[ludoo]

It's probably easier if you run checks locally without waiting for the workflow to kick in. Details are in the contributing guide in the root of the repo. :)

[wiktorn]

I think that to be fully comprehensive, this requires allowing additional overrides in net-lb-ext for names of:

• google_compute_region_backend_service
• google_compute_service_attachment

[cvanwijck-hub24]

I think that to be fully comprehensive, this requires allowing additional overrides in net-lb-ext for names of:

* google_compute_region_backend_service

* google_compute_service_attachment

If "fully comprehensive" is the goal, this could be expanded to adding override names across multiple other modules. This would also partially resolve #2419. We have encountered this across many areas of our deployment in taking existing click-ops configured infrastructure under control of Terraform but trying to use CFF to accelerate development. Overrides would be useful for many brownfield deployments.

[juliocc]

This PR is getting messy. I extracted the changes to the peering module to #2459.

[juliocc]

@cvanwijck-hub24, just checking in to see if you plan on finishing this PR. If not, we'll go ahead and close it

[coopervw]

@cvanwijck-hub24, just checking in to see if you plan on finishing this PR. If not, we'll go ahead and close it

Yes I will resolve the outstanding issues this week if possible.

[cvanwijck-hub24]

All use coalesce and changed override_name to use just name for clarity

[juliocc]

lgtm now. Thanks for your patience @cvanwijck-hub24