The given key does not identify an element in this collection value

[rust84]

Describe the Bug

We are getting the following error when running apply. We are in the process of upgrading from Terraform 0.11 to Terraform 0.12. Previously this was successful on Terraform 0.11 using the 0.11 branch.

Error: Invalid index

  on .terraform/modules/staging_peering/accepter.tf line 88, in resource "aws_route" "accepter":
  88:   route_table_id            = local.accepter_aws_route_table_ids[ceil(count.index / local.requester_cidr_block_associations_count)]
    |----------------
    | count.index is 5
    | local.accepter_aws_route_table_ids is list of string with 3 elements
    | local.requester_cidr_block_associations_count is 2

The given key does not identify an element in this collection value.

Expected Behavior

Plan runs without error.

Steps to Reproduce

Steps to reproduce the behavior:

1. Configure the module as follows.

module "staging_peering" {
  source  = "cloudposse/vpc-peering-multi-account/aws"
  version = "0.11.3"

  namespace = "staging"
  stage     = "staging"
  name      = "staging-shared-services-peering"

  requester_aws_assume_role_arn             = "arn:aws:iam::xxxxxx:role/cross-account-vpc-peering"
  requester_region                          = "eu-west-1"
  requester_vpc_id                          = data.aws_vpc.peer_from_vpc.id
  requester_allow_remote_vpc_dns_resolution = false

  accepter_aws_assume_role_arn             = "arn:aws:iam::xxxxxx:role/pipeline"
  accepter_region                          = "us-east-2"
  accepter_vpc_id                          = data.aws_vpc.peer_to_staging_vpc.id
  accepter_allow_remote_vpc_dns_resolution = false
}

2. Run 'terraform plan.'
3. See error

Environment (please complete the following information):

Anything that will help us triage the bug will help. Here are some ideas:

• Version 0.11.3
• Terraform 0.12.30

[rust84]

Removed from the state and tried recreating but still the same issue.

[nitrocode]

Do you get the same error if you use the latest version of this module ?

[rust84]

If I try 0.15.0 then I get the following error

Error: Custom variable validation is experimental

  on .terraform/modules/hxm-qa_peering/context.tf line 182, in variable "label_key_case":
 182:   validation {

This feature is currently an opt-in experiment, subject to change in future
releases based on feedback.

Activate the feature for this module by adding variable_validation to the list
of active experiments.

I've tried forking the module and enabling the experiment but wherever I put it I still get the error.

terraform {
  experiments = [variable_validation]
}

We are using terraform 0.12.30.

[runtman]

I work with @rust84 it seems upgrading to terraform 0.13.7 has resolved this issue.

[nitrocode]

It looks like upgrading terraform resolves the issue. Thanks for closing the loop @runtman .