Difference using modules with count and for_each

Terraform Providers
1

Hello

I faced with problem using modules with for_each instead count. I’m trying use modules like described below, and get error:

    Error: Unsupported attribute

      on cloud_configure.tf line 192, in module "user":
     192:   user_group_id = [for x in module.ug[*].ug: x.id if x.label == each.value.user_group_label][0]

    This object does not have an attribute named "label".

    Error: Unsupported attribute

      on cloud_configure.tf line 193, in module "user":
     193:   bucket_id     = [for x in module.bucket[*].bucket: x.id if x.label == each.value.bucket_label][0]

    This object does not have an attribute named "label".

When previously I use count and local.cloud_config was declared as arrays of object I didn’t have this error on terraform plan stage

module "user" {
  count         = length(local.cloud_config["user"])
  source        = "../terraform-modules/user"
  email         = local.cloud_config["user"][count.index].email
  login         = local.cloud_config["user"][count.index].login

  user_group_id = [for x in module.ug[*].ug: x.id if x.label == local.cloud_config["user"][count.index].user_group_label][0]
  bucket_id     = [for x in module.bucket[*].bucket: x.id if x.label == local.cloud_config["user"][count.index].bucket_label][0]
}

So where I wrong?

    locals {
      cloud_config = {
        "user_group" = {
          "tf_ug" = {
            bucket_labels = [
              "tf_bucket"
            ]
          }
        }

        "bucket" = {
          "tf_bucket" = {
            currency_code = "USD"
            monthly_price = 10
          }
        },

        "user" = {
          "user1" = {
            role_labels      = [
              "tf_role1",
              "tf_role3"
            ]
            user_group_label = "tf_ug"
            bucket_label     = "tf_bucket"
          }
        }
      }
    }

    module "bucket" {
      for_each      = local.cloud_config["bucket"]
      source        = "../terraform-modules/bucket"
      currency_code = each.value.currency_code
      label         = each.key
      monthly_price = each.value.monthly_price
    }

    module "ug" {
      for_each   = local.cloud_config["user_group"]
      source     = "../terraform-modules/user_group"
      label      = each.key
    }

    module "user" {
      for_each      = local.cloud_config["user"]
      source        = "../terraform-modules/user"

      role_ids      = flatten([for i in each.value.role_labels : [for r in module.role[*].role : r.id if r.label == i ] ])

      user_group_id = [for x in module.ug[*].ug: x.id if x.label == each.value.user_group_label][0]
      bucket_id     = [for x in module.bucket[*].bucket: x.id if x.label == each.value.bucket_label][0]
    }
2

Using for_each the module references are based on keys instead of an index.

3

You could start using module outputs to make the module data structures “visible”.

4

This is my module output for user_group module.

output "ug" {
  value = user_group.ug
}

As I understand I can’t use construction like this, only should specifies some key?

module.ug[*].ug

But how I can resolve my problem if I want iterate all created user_groups?

5

That’s my understanding, yes.

So, you have to use a for expression.

6

Maybe I don’t understand but I allready use this…

user_group_id = [for x in module.ug[*].ug: x.id if x.label == each.value.user_group_label][0]

And got error like on the top of the topic…

7

It might be rather like (not tested):

user_group_id = [for xx in module.ug: [for x in xx.ug : x.id if x.label == each.value.user_group_label][0]]
8

Hey,

Nope it didn’t work…
I’m trying run some test in console and got next results, looks like I got only values, but don’t have keys… now I understand where is problem, but don’t know how to fix it…

> [ for xx in module.ug: [ for x in xx.ug: x ]]
[
  [
    {},
    0,
    [
      1,
    ],
    "2021-01-13T11:16:56.000Z",
    0,
    0,
    0,
    "5",
    "qzjkvbgvgdoxkt",
    "tf_ug",
    false,
    0,
    null,
    [],
    "2021-01-13T11:16:56.000Z",
    [],
  ],
 ]
9

Okay, looks like I’m finally fix this :slight_smile: should be

user_group_id = flatten([ for xx in module.ug: [ for x in xx: x.id if x.label == each.value.user_group_label ] ])[0]
10

That’s a good start. Depending on your data structures k,v can be access using pattern like for k,v in map : ...