Enabling later Reassignment of reserved Public IPs to Private IPs in Terraform (as in the console)

[brokedba]

Community Note

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Description

We would like to reuse existing reserved public IPs created using resource "oci_core_public_ip". But assign it afterward to any compute resource (lb,instance).
But for now there is no way to do it in terraform.

• If the oci_core_public_ip is created with the instance it will be destroyed as well which defeats the purpose of reserved IPs.
• The block resource "oci_core_instance" does not have an option to attach or associate the VNIC to an existing public IP.

create_vnic_details {} has only a boolean attribute linked to public IPs.
#assign_public_ip ⇒ BOOLEAN Whether the VNIC should be assigned a public IP address.

However it is definitely possible to later assign an existing Public IP to a VNIC through rest API (UpdatePublicIp) or via the console as shown below

• Similar issues/requests were created Use reserved public IP when creating instance #1565 and oci_core_instance assigning oci_core_public_ip #1730 and here Option to Choose IP address when creating compute instance #1458

New or Affected Resource(s)

either of the 2

1. resource "oci_core_instance" could be modified to allow this option. Maybe a new resource to assign and unassign public ip.
2. new/updated resource "oci_core_public_ip_assign/modify" to allow assignment modification

Potential Terraform Configuration

since REST API has it already it won't require reinventing the wheel.

• Option A. A new section that assign a VNIC. This would be the most basic since OCI allows more VNIC.

resource "oci_core_instance" "test_instance" {
    ...
    assign_vnic_details {
        public_ip = oci_core_public_ip.test_public_ip.id
        ...
    }
    ...
}

• Option B. new oci_core_public_ip_assign resource

resource "oci_core_public_ip_assign" "test_public_ip_assign" {
    #Required
    compartment_id  = var.compartment_id  # target private IP compartment
    id                         =  oci_core_public_ip.test_public_ip.id
    private_ip_id        = var.public_ip_private_ip_id #  oci_core_private_ip.myvnic_private_ip.id
...
}

Proposed Workaround that doesn't work

A workaround has already proposed couple of times here #1565 (comment) and here #1649 (comment)
But it doesn't work
example :

resource "oci_core_public_ip" "bastion_ip" {
  compartment_id = var.network_compartment_id != "" ? var.network_compartment_id : var.compartment_id
  display_name   = var.bastion_identifier != "" ? join("-", ["ip-bastion-pub", var.bastion_identifier]) : "ip-bastion-pub"
  lifetime       = "RESERVED"
  private_ip_id  = data.oci_core_private_ips.bastion.private_ips[0]["id"]

  defined_tags = var.defined_tags

  lifecycle {
    prevent_destroy = true
  }
}

But your terraform destroy will fail miserably as shown below .

╷
│ Error: Instance cannot be destroyed
│
│   on compute.tf line 91:
│   91: resource "oci_core_public_ip" "bastion_ip" {
│
│ Resource oci_core_public_ip.bastion has lifecycle.prevent_destroy set, but the plan calls for this resource to be destroyed. To
│ avoid this error and continue with the plan, either disable lifecycle.prevent_destroy or reduce the scope of the plan using the -target flag.
╵

terraform is clean, don't make it dirty.

[ravinitp]

Thank you for reporting the issue. We have raised an internal ticket to track this. Our service engineers will get back to you.

[ravinitp]

Thank you for reporting the issue. We have raised an internal ticket to track this. Our service engineers will get back to you.

[ravinitp]

Thank you for reporting the issue. We have raised an internal ticket to track this. Our service engineers will get back to you.

[ravinitp]

Thank you for reporting the issue. We have raised an internal ticket to track this. Our service engineers will get back to you.

[ravinitp]

We have notified our service engineer. Our service engineers will get back to you.

[ravinitp]

We have notified our service engineer. Our service engineers will get back to you.

[brokedba]

Any update on this request ?

[fharris]

Interested as well.

[dhoogfr]

You can reassign a reserved public IP (or set it "free") by changing the assignment.
What I do is to create an instance with the "assign_public_ip" attribute set to "false".
I reserve a public IP and then assign that public IP to the instance.

When I need to destroy the instance, I need to remove the assignment in the "oci_core_public_ip" resource or replace it with another assignment.

resource "oci_core_public_ip" "bastion" {
  compartment_id = var.network_compartment_id != "" ? var.network_compartment_id : var.compartment_id
  display_name   = var.bastion_identifier != "" ? join("-", ["ip-bastion-pub", var.bastion_identifier]) : "ip-bastion-pub"
  lifetime       = "RESERVED"
  private_ip_id  = data.oci_core_private_ips.bastion.private_ips[0]["id"]

  defined_tags = var.defined_tags

  lifecycle {
    prevent_destroy = true
  }

}


resource "oci_core_instance" "bastion" {
  compartment_id      = var.compartment_id
  availability_domain = var.availability_domain
  fault_domain        = var.fault_domain
  display_name        = var.bastion_identifier != "" ? join("-", ["bastion", var.bastion_identifier]) : "bastion"
  shape               = local.bastion_instance_shape

  create_vnic_details {
    display_name     = "primaryvnic"
    hostname_label   = var.bastion_hostname
    assign_public_ip = false
    subnet_id        = oci_core_subnet.bastion.id
    nsg_ids          = [oci_core_network_security_group.bastion_host.id]
  }

  source_details {
    source_type = "image"
    source_id   = var.bastion_image_id
  }

  shape_config {
    memory_in_gbs = var.bastion_memory
    ocpus         = var.bastion_ocpus
  }

  metadata = {
    ssh_authorized_keys = var.ssh_public_key
  }

  defined_tags  = var.defined_tags
  freeform_tags = var.freeform_tags

}

[thpham]

Any update on this request ? I'm interested too !

[RenatoOneCloudSys]

To destroy the instance without destroying the public ip, first I had to comment the line private_ip_id on the oci_core_public_ip that related to the instance and run apply so terraform will detach the ip from the instance, then I can destroy targeting the oci_core_instance

[rafaelhneves]

Hello, i am very interested in that.

Best Regards.