Route unable to destroy if RouteTable not present

[t-pascal]

A destroy on routes attached to a route table fail if the route table has already been destroyed or is missing, even if the route table is missing from the state file. The simplest fix is to create a dummy route table and let it get destroyed but this is manual and mucks with the state file. There is no way to delete a route via the console, so that would be a CLI issue that could be scripted.

I am still using 0.6.16 because I haven't upgraded with breaking changes in 0.7. If someone can please validate this in 0.7 that would help.

Terraform Version

I do not believe this is a version-dependent issue.

$ /var/tmp/terraform -v
Terraform v0.6.16

Your version of Terraform is out of date! The latest version
is 0.7.1. You can update by downloading from www.terraform.io

Affected Resource(s)

• route
• route table (indirectly)

Terraform Configuration Files

resource "aws_route_table" "private" {
  count = "${length(split(",", var.aws_availability_zones))}"
  vpc_id = "${aws_vpc.main.id}"
  propagating_vgws = ["${var.vgw_id}"]

  tags {
    Name = "${var.name}:private:${element(split(",", var.aws_availability_zones), count.index)}"
  }
}

resource "aws_route" "private_route" {
    count = "${length(split(",", var.aws_availability_zones))}"
    route_table_id = "${element(aws_route_table.private.*.id, count.index)}"
    destination_cidr_block = "0.0.0.0/0"
    nat_gateway_id = "${element(aws_nat_gateway.main.*.id, count.index)}"
    depends_on = ["aws_route_table.private"]
}

Debug Output

Error refreshing state: 2 error(s) occurred:

* aws_route.private_route.0: Error while checking if route exists: InvalidRouteTableID.NotFound: The routeTable ID 'rtb-160c1372' does not exist
        status code: 400, request id: 1de4107d-a140-4545-a31d-cbab7a18e5a9
* aws_route.private_route.2: Error while checking if route exists: InvalidRouteTableID.NotFound: The routeTable ID 'rtb-150c1371' does not exist
        status code: 400, request id: 66a12dc2-479f-4159-a4c3-d6355b0ab4b7

Expected Behavior

When a route table has been destroyed, this should be obvious to terraform and it should proceed appropriately: either recreate the resource or decide that it is gone so no further action is required.

Actual Behavior

Terrfaform is unable to destroy the route if the route-table has already been destroyed or if it is manually deleted or is missing.

Steps to Reproduce

1. terraform apply
2. Delete the autoscaling group (Via the console or api)
3. terraform destroy

Important Factoids

The route-table might actually be destroyed incorrectly by terraform: that is, the routes should be destroyed before the route-table is destroyed. This is likely the source of the confusion. However, it should be a noop either way.

References

• Very similar error message to Autoscaling policy unable to destroy if autoscaling group not present #8386 but for different resources. I think Terraform is being too strict in the validation of deleting resources. It's possible 400 is not a good error code from the SDK.

[t-pascal]

Thanks stack72!

[ghost]

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