[Enhancement]: User Defined IP on VPC endpoints

[ckotil]

Description

AWS recently added support for VPC Endpoints allowing to pick your own IP:
https://aws.amazon.com/about-aws/whats-new/2023/08/aws-privatelink-user-defined-ip-vpc-endpoints/

The Console UI now supports this as well (step 8):
https://docs.aws.amazon.com/vpc/latest/privatelink/create-interface-endpoint.html#create-interface-endpoint-aws

It looks like this new capability has not yet made its way to the AWS Provider yet.

One approach could be to allow the aws_vpc_endpoint resource to specify the network_interface_ids. Requiring the Network Interfaces to be provisioned before the VPC Endpoint, and allowing users to choose an IP.

╷
│ Error: Value for unconfigurable attribute
│
│   with aws_vpc_endpoint.this,
│   on main.tf line 3, in resource "aws_vpc_endpoint" "this":
│    3:     network_interface_ids = [
│    4:         aws_network_interface.test1.id,
│    5:         aws_network_interface.test2.id,
│    6:     ]
│
│ Can't configure a value for "network_interface_ids": its value will be decided automatically based on the result of applying this
│ configuration.

Thanks,
--Chad

Affected Resource(s) and/or Data Source(s)

aws_vpc_endpoint

Potential Terraform Configuration

resource "aws_vpc_endpoint" "this" {
    ip_address_type       = "ipv4"
//    network_interface_ids = [
//        aws_network_interface.test1.id
//        aws_network_interface.test2.id
//    ]
    policy                = jsonencode(
        {
            Statement = [
                {
                    Action    = "*"
                    Effect    = "Allow"
                    Principal = "*"
                    Resource  = "*"
                },
            ]
        }
    )
    private_dns_enabled   = true
    route_table_ids       = []
    security_group_ids    = [
        "sg-0707d83e8bad17a68",
    ]
    service_name          = "aws.sagemaker.us-west-2.studio"
    subnet_ids            = [
        "subnet-06fb9377a141332d4",
        "subnet-0b92395c83428cea0",
    ]
    tags                  = {"Name" = "ckotil-test-tf"}
    tags_all              = {}
    vpc_endpoint_type     = "Interface"
    vpc_id                = "vpc-0c5247b14f09aea8a"

    dns_options {
        dns_record_ip_type                             = "ipv4"
        private_dns_only_for_inbound_resolver_endpoint = false
    }

    timeouts {}
}

resource "aws_network_interface" "test1" {
  subnet_id       = "subnet-06fb9377a141332d4"
  private_ips     = ["10.168.184.81"]
  security_groups = ["sg-0707d83e8bad17a68"]
  tags                  = {"Name" = "ckotil-test-tf-1"}
}

resource "aws_network_interface" "test2" {
  subnet_id       = "subnet-0b92395c83428cea0"
  private_ips     = ["10.168.184.243"]
  security_groups = ["sg-0707d83e8bad17a68"]
    tags                  = {"Name" = "ckotil-test-tf-2"}
}

References

No response

Would you like to implement a fix?

No

[github-actions]

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[noneymous]

What's the current status on this?

[ckotil]

What's the current status on this?

No movement yet. I think the issue needs more upvotes.

[noneymous]

Alright, I upvoted it too, there are some upvotes already :)

I'm not quite sure why this is not implemented or not more popular. The aws_vpc_endpoint resource is not practical currently. It leads to race conditions for the same private IPs, competing with other instances (with fixed IPs) defined in the remaining terraform script. Introducing another subnet for the endpoints just to compensate for the unpredictability is a bit of an overhead.

Furthermore, having an endpoint that has a different IP each time it is (re-)created, is a bit contrary to its purpose. Obviously, other instances have a more or less static configuration trying to connect to it.

Furthermore, it's also not easy to read the finally applied private IP with terraform, in order to update other resources.

[ddericco]

This is being worked on.

[github-actions]

Warning

This issue has been closed, meaning that any additional comments are hard for our team to see. Please assume that the maintainers will not see them.

Ongoing conversations amongst community members are welcome, however, the issue will be locked after 30 days. Moving conversations to another venue, such as the AWS Provider forum, is recommended. If you have additional concerns, please open a new issue, referencing this one where needed.

[github-actions]

This functionality has been released in v5.54.0 of the Terraform AWS Provider. Please see the Terraform documentation on provider versioning or reach out if you need any assistance upgrading.

For further feature requests or bug reports with this functionality, please create a new GitHub issue following the template. Thank you!

[github-actions]

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.
If you have found a problem that seems similar to this, please open a new issue and complete the issue template so we can capture all the details necessary to investigate further.