google_compute_forwarding_rule description field causes resource replacement

steven-edgar commented 11 months ago

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Terraform Version

Terraform v1.4.0 Google terraform provider v4.84.0

Affected Resource(s)

google_compute_forwarding_rule

Terraform Configuration Files

resource "google_compute_forwarding_rule" {
  name = "example"
  description = "Forwarding rule description"
  region = "europe-west1"
  network = var.network
  ip_address = "1.2.3.4"
 target = var.cloudsql_psc_instance_attachment
  allow_psc_global_access = true 
}

Debug Output

Panic Output

Expected Behavior

On first apply the forwarding rule is created, on second run the resource is left unchanged.

Actual Behavior

# from https://github.com/hashicorp/terraform-provider-google/issues/16258

resource "google_compute_forwarding_rule" "default" {
  name                    = "psc-endpoint"
  description             = "My description"
  region                  = "us-central1"
  load_balancing_scheme   = ""
  target                  = google_compute_service_attachment.producer_service_attachment.id
  network                 = google_compute_network.consumer_net.name
  ip_address              = google_compute_address.consumer_address.id
  allow_psc_global_access = true
}

That can be applied once, causing the resource to be created. But a second tf apply (with no changes to the tf file) causes a plan that includes deletion/recreation, because of description:

  # google_compute_forwarding_rule.default must be replaced
-/+ resource "google_compute_forwarding_rule" "default" {
      - all_ports               = false -> null
      - allow_global_access     = false -> null
      + base_forwarding_rule    = (known after apply)
      ~ creation_timestamp      = "2023-10-16T09:32:38.274-07:00" -> (known after apply)
      + description             = "My description" # forces replacement

Plan: 1 to add, 0 to change, 1 to destroy.

Steps to Reproduce

Set the "description" field in the resource. If this field is unset and the configuration is applied, subsequent applies make no changes.

Important Factoids

This is with a PSC enabled forwarding rule, I've not tried with non-PSC forwarding rules.

References

0000

b/308569872

edwardmedia commented 11 months ago

The description is set to ForceNew in the code

It does look like update is supported for description with its api

rileykarson commented 11 months ago

Update support is an enhancement, not a bug.

justinsb commented 11 months ago

I don't think this issue is about update behaviour.

The bug is that when you tf apply a PSC forwarding rule with a description twice - with no changes - the second tf apply forces replacement because TF thinks the description field is changing.

rileykarson commented 11 months ago

Ah, yep, https://github.com/hashicorp/terraform-provider-google/issues/16258 was more clear (although this issue's body stated the same if read correctly). Edited the issue body.

rileykarson commented 11 months ago

@roaks3 any idea why the robot didn't label this one?

roaks3 commented 11 months ago

Ah yea, there is a manual step where a member of our team needs to update the team enrollment in mmv1 (the canonical source is internal) and then re-run the labeler. This is part of our team's rotation so it should happen weekly until we build automation around that.

LucaPrete commented 8 months ago

I'm not 100% sure how the PSC specific thing it's related to the description. In the meantime I tried to make the description argument updatable in place. I think this step is anyway needed and possibly it might also fix the bug.

LucaPrete commented 8 months ago

It seems tests are failing as we are not (yet) able to patch the description argument. I'll dig into it with product before abandoning the PR.

LucaPrete commented 8 months ago

I had to abandon the PR as description patching is currently not supported.

stenalpjolly commented 6 months ago

The same issue is present in the compute_global_forwarding_rule as well.

hashicorp / terraform-provider-google