aws_route: Unable to use destination_ipv6_cidr_block with nat_gateway_id

[jplock]

Community Note

• Please vote on this issue by adding a 👍 reaction to the original issue to help the community and maintainers prioritize this request
• Please do not leave "+1" or other comments that do not add relevant new information or questions, they generate extra noise for issue followers and do not help prioritize the request
• If you are interested in working on this issue or have submitted a pull request, please leave a comment

Terraform CLI and Terraform AWS Provider Version

Affected Resource(s)

aws_route

Terraform Configuration Files

Please include all Terraform configurations required to reproduce the bug. Bug reports without a functional reproduction may be closed without investigation.

resource "aws_vpc" "this" {
  cidr_block                       = "10.0.0.0/16"
  enable_dns_support               = true
  enable_dns_hostnames             = true
  assign_generated_ipv6_cidr_block = true
}

resource "aws_internet_gateway" "this" {
  vpc_id = aws_vpc.this.id
}

resource "aws_egress_only_internet_gateway" "this" {
  vpc_id = aws_vpc.this.id
}

resource "aws_subnet" "this" {
  vpc_id                                         = aws_vpc.this.id
  assign_ipv6_address_on_creation                = true
  enable_dns64                                   = true
  enable_resource_name_dns_aaaa_record_on_launch = true
  enable_resource_name_dns_a_record_on_launch    = true
  private_dns_hostname_type_on_launch            = "resource-name"
  cidr_block                                     = "10.0.0.0/24"
  ipv6_cidr_block                                = cidrsubnet(aws_vpc.this.ipv6_cidr_block, 8, 1)
  availability_zone                              = "us-east-1a"

  lifecycle {
    ignore_changes = [
      availability_zone
    ]
  }
}

resource "aws_route_table" "this" {
  vpc_id = aws_vpc.this.id
}

resource "aws_eip" "this" {
  vpc = true

  depends_on = [aws_internet_gateway.this]
}

resource "aws_route_table_association" "this" {
  subnet_id      = aws_subnet.this.id
  route_table_id = aws_route_table.this.id
}

resource "aws_nat_gateway" "this" {
  allocation_id = aws_eip.this.id
  subnet_id     = aws_subnet.this.id

  depends_on = [aws_internet_gateway.this]

  lifecycle {
    create_before_destroy = true
  }
}

resource "aws_route" "this" {
  route_table_id              = aws_route_table.this.id
  destination_ipv6_cidr_block = "64:ff9b::/96"
  nat_gateway_id              = aws_nat_gateway.this.id
}

Debug Output

Panic Output

Did not panic

Expected Behavior

Able to set destination_ipv6_cidr_block to 64:ff9b::/96 with a nat_gateway_id

Actual Behavior

Error: Conflicting arguments

"nat_gateway_id": conflicts with destination_ipv6_cidr_block

Steps to Reproduce

1. terraform apply

Important Factoids

• Error is coming from https://github.com/hashicorp/terraform-provider-aws/blob/main/internal/service/ec2/route.go#L121

References

• Per https://docs.aws.amazon.com/vpc/latest/userguide/nat-gateway-nat64-dns64.html#nat-gateway-nat64-dns64-walkthrough, we should be able to use destination_ipv6_cidr_block and nat_gateway_id
• https://aws.amazon.com/blogs/aws/let-your-ipv6-only-workloads-connect-to-ipv4-services/
• Region expansion announcement

[github-actions]

This functionality has been released in v4.4.0 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.