Updating the infoblox_ip_allocation will not update allocated_ipv6_addr

[pawelos99]

For a given terraform infoblox_ip_allocation definition:

terraform {
  required_providers {
    infoblox = {
      source  = "infobloxopen/infoblox"
      version = "~> 2.7.0"
    }
  }
}

resource "infoblox_ip_allocation" "load_balancers" {
  fqdn  = "<your fqdn>"
  ipv4_cidr = "<your ipv4 cidr>"
  ipv6_cidr = null
}

output "load_balancer_vip_ipv6" {
  value     = infoblox_ip_allocation.load_balancers.allocated_ipv6_addr
}

output "load_balancer_vip_ipv4" {
  value     = infoblox_ip_allocation.load_balancers.allocated_ipv4_addr
}

running terraform apply will create infoblox_ip_allocation with allocated_ipv4_addr and empty allocated_ipv6_addr:

terraform apply

Terraform used the selected providers to generate the following execution plan. Resource actions are indicated with the following symbols:
  + create

Terraform will perform the following actions:

  # infoblox_ip_allocation.load_balancers will be created
  + resource "infoblox_ip_allocation" "load_balancers" {
      + allocated_ipv4_addr = (known after apply)
      + allocated_ipv6_addr = (known after apply)
      + dns_view            = (known after apply)
      + enable_dns          = true
      + fqdn                = "<your fqdn>"
      + id                  = (known after apply)
      + internal_id         = (known after apply)
      + ipv4_cidr           = "<your ipv4 cidr>"
      + network_view        = "default"
      + ref                 = (known after apply)
      + ttl                 = -2147483648
    }

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

Changes to Outputs:
  + load_balancer_vip_ipv4 = (known after apply)
  + load_balancer_vip_ipv6 = (known after apply)

Do you want to perform these actions?
  Terraform will perform the actions described above.
  Only 'yes' will be accepted to approve.

  Enter a value: yes

infoblox_ip_allocation.load_balancers: Creating...
infoblox_ip_allocation.load_balancers: Creation complete after 1s [id=99960f1e-b033-4606-a94a-d552346250df]

Apply complete! Resources: 1 added, 0 changed, 0 destroyed.

Outputs:

load_balancer_vip_ipv4 = "<ipv4 addr>"
load_balancer_vip_ipv6 = ""

But now adding the ipv6_cidr:

resource "infoblox_ip_allocation" "load_balancers" {
  fqdn  = "<your fqdn>"
  ipv4_cidr = "<your ipv4 cidr>"
  ipv6_cidr = "<your ipv6 cidr>"
}

will not output allocated_ipv6_addr (note that the output is still empty) even if it was correctly created by infoblox:

terraform apply
infoblox_ip_allocation.load_balancers: Refreshing state... [id=99960f1e-b033-4606-a94a-d552346250df]

Terraform used the selected providers to generate the following execution plan. Resource actions are indicated with the following symbols:
  ~ update in-place

Terraform will perform the following actions:

  # infoblox_ip_allocation.load_balancers will be updated in-place
  ~ resource "infoblox_ip_allocation" "load_balancers" {
        id                  = "99960f1e-b033-4606-a94a-d552346250df"
      + ipv6_cidr           = "<your ipv6 cidr>"
        # (11 unchanged attributes hidden)
    }

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

Do you want to perform these actions?
  Terraform will perform the actions described above.
  Only 'yes' will be accepted to approve.

  Enter a value: yes

infoblox_ip_allocation.load_balancers: Modifying... [id=99960f1e-b033-4606-a94a-d552346250df]
infoblox_ip_allocation.load_balancers: Modifications complete after 1s [id=99960f1e-b033-4606-a94a-d552346250df]

Apply complete! Resources: 0 added, 1 changed, 0 destroyed.

Outputs:

load_balancer_vip_ipv4 = "<ipv4 addr>"
load_balancer_vip_ipv6 = ""

only a terraform refresh or another terraform apply will set this value correctly.

Suspicious logs when the trace logging is enabled:

2024-07-29T17:00:05.960+0200 [WARN]  Provider "provider[\"registry.terraform.io/infobloxopen/infoblox\"]" produced an unexpected new value for infoblox_ip_allocation.load_balancers, but we are tolerating it because it is using the legacy plugin SDK.
    The following problems may be the cause of any confusing errors from downstream operations:
      - .allocated_ipv6_addr: was cty.StringVal(""), but now cty.StringVal("<new ipv6 addr>")

terraform version:

terraform --version
Terraform v1.9.1
on linux_amd64
+ provider registry.terraform.io/hashicorp/null v3.2.2
+ provider registry.terraform.io/infobloxopen/infoblox v2.7.0

Your version of Terraform is out of date! The latest version
is 1.9.3. You can update by downloading from https://www.terraform.io/downloads.html