Panic when using for and for_each iterating through list(map(string))

[jvelasquezjs]

Terraform Version

terraform -v
Terraform v0.12.6
+ provider.aws v2.22.0

Terraform Configuration Files

my module in `./module

variable "zone_id" {
  description = "The id of the zone to create records in."
}

variable "records_list" {
  description = "List records. Each record is a map formed by `name`, `record` and `ttl` optionally."
  type        = list(map(string))

  default = [
    {
      "name"   = "example"
      "record" = "1.2.3.4"
    },
  ]
}

variable "records_count" {
  description = "Number of records to create, has to be set to the number of records in the records_list."
  default     = 0
}

resource "aws_route53_record" "record" {
  # for_each = var.records_list

  for_each = [for r in var.records_list : {
    r_name   = lookup(r, "name", null)
    r_type   = lookup(r, "type", "CNAME")
    r_ttl    = lookup(r, "ttl", 60)
    r_record = lookup(r, "record", null)
  }]

  zone_id = var.zone_id
  name    = each.value.r_name
  type    = each.value.r_type
  ttl     = each.value.r_ttl
  records = each.value.r_record
}

using the module

resource "aws_route53_zone" "test" {
  name = "nowhere.example.co.uk"
}

module "test" {
  source        = "./module"
  zone_id       = aws_route53_zone.test.id
  records_count = 1

  records_list = [
    {
      "name"   = "aaa"
      "type"   = "CNAME"
      "record" = "bbb.nowhere.example.co.uk"
    },
  ]
}

Debug Output

Crash Output

https://gist.github.com/jvelasquezjs/262fdb16e7d18e1272c424e8d08fa18c

Expected Behavior

Not to panic...

Actual Behavior

Panic due to string not expected

Steps to Reproduce

terraform init
AWS_DEFAULT_REGION=eu-west-1 terraform plan

Additional Context

References

[wata727]

This looks like the same issue as #22305.

[pselle]

@wata727 is correct! This is fixed in master and will be released in 0.12.7 of Terraform (and I'll leave this open until that is out, and have self-assigned to do so).

To work around this, ensure that you are passing a set and not a list (which Terraform is interpreting as a tuple) to for_each using the toset() function.

Thank you for the report!

[pselle]

Terraform 0.12.7 (with this fix) is now released! https://github.com/hashicorp/terraform/blob/v0.12.7/CHANGELOG.md

[sc250024]

@pselle I have a very similar example to @jvelasquezjs (with the lookup function and everything) and I'm using Terraform v0.12.7, but for some reason, I'm getting this error:

The given "for_each" argument value is unsuitable: the "for_each" argument
must be a map, or set of strings, and you have provided a value of type tuple.

Can we not pass in a list(map(string)) type variable? How would you modify @jvelasquezjs 's example in the aws_route53_record to make it a set? I've tried the equivalent of:

  for_each = toset([for r in var.records_list : {
    r_name   = lookup(r, "name", null)
    r_type   = lookup(r, "type", "CNAME")
    r_ttl    = lookup(r, "ttl", 60)
    r_record = lookup(r, "record", null)
  }])

But I get the same error as above. And also this...

  for_each = toset(var.records_list)

But I get this...

The given "for_each" argument value is unsuitable: "for_each" supports maps
and sets of strings, but you have provided a set containing type map of
string.

[sc250024]

Actually I found a solution for my above comment here: #22610 (comment). However, I'm not sure why map(map(string)) is fine, but this example of list(map(string)) somehow breaks it.

[t5unamie]

@sc250024 can you post the working example. Messing around with different options is not ver clear to me which code change worked for the original example.

[sc250024]

@t5unamie Yep. I was using it to make a module for GitLab repositories.

vars.tf

variable "branch_protection_map" {
  default = {
    master = {
      merge_access_level = "developer"
      push_access_level  = "maintainer"
    }
  }
  description = "Map of branch / access-level mappings to protected branches."
  type        = map(map(string))
}

main.tf

resource "gitlab_branch_protection" "this" {
  for_each = var.branch_protection_map

  project            = gitlab_project.this.id
  branch             = each.key
  merge_access_level = lookup(each.value, "merge_access_level", "developer")
  push_access_level  = lookup(each.value, "push_access_level", "maintainer")
}

I guess Terraform needs a key as in the each.key part. Hopefully that works for you.

[t5unamie]

@sc250024 thanks

[ghost]

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