google_compute_target_pool is not idempotent when using URLs as values from google_compute_instance

[hashibot]

This issue was originally opened by @jsierles as hashicorp/terraform#9121. It was migrated here as part of the provider split. The original body of the issue is below.

---

Hi there,

Terraform v0.7.4
google_compute_target_pool

resource "google_compute_target_pool" "loadbalancer" {
  name = "target-pool-loadbalancer-${var.env}"
  instances = ["${google_compute_instance.loadbalancer.*.self_link}"]
  health_checks = ["${google_compute_http_health_check.loadbalancer.name}"]
}

Plan output

~ google_compute_target_pool.loadbalancer
    instances.0: "europe-west1-d/loadbalancer-0-staging" => "https://www.googleapis.com/compute/v1/projects/myproject-com/zones/europe-west1-d/instances/loadbalancer-0-staging"
    instances.1: "europe-west1-d/loadbalancer-1-staging" => "https://www.googleapis.com/compute/v1/projects/myproject-com/zones/europe-west1-d/instances/loadbalancer-1-staging"

Expected Behavior

This value should not be changed on every plan/apply run.

Actual Behavior

On every plan and apply, this resource is modified without makes changes to the configuration.

[ghost]

I'm going to lock this issue because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active issues.

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