How to access a sequence in a map inside a for_each loop in Terraform

Question

Using Terraform, I have a list of maps defined as variable eg

storage_accounts = {

  stacctest1 = {
    resource_group_name      = "testrg",
    location                 = "uksouth",
    account_tier             = "Standard",
    account_replication_type = "GRS",
    containers_list = [
      { name = "test_private_x", access_type = "private" },
      { name = "test_blob_x", access_type = "blob" },
      { name = "test_container_x", access_type = "container" }
    ]
  }

  stacctest2 = {
    resource_group_name      = "testrg",
    location                 = "uksouth",
    account_tier             = "Standard",
    account_replication_type = "GRS",
    containers_list = [
      { name = "test_private_a", access_type = "private" },
      { name = "test_blob_a", access_type = "blob" },
      { name = "test_container_a", access_type = "container" }
    ]    
  }

} 

Then in a module, I can use a for_each loop to go through each item in the list to create each storage account, eg

resource "azurerm_storage_account" "storage" {
  for_each = var.storage_accounts

  name                     = each.key
  resource_group_name      = each.value.resource_group_name
  location                 = each.value.location
  account_tier             = each.value.account_tier
  account_replication_type = each.value.account_replication_type
  }
}

To process the container sequence in the map, I was thinking I can just loop though the list again process the containers, but struggling to work out how to fit a nested loop in with resource "azurerm_storage_container"

Answer 1

You have to flatten your variable. For example:

locals {
  flat_storage_accounts = merge([
    for account_name, details in var.storage_accounts: {
        for container in details.containers_list: 
          "${account_name}-${container.name}" => 
            merge(details, {
                "account_name" = account_name
                "container" = container
                })
      }
  ]...)
}

then

resource "azurerm_storage_account" "storage" {
  for_each = local.flat_storage_accounts

  name                     = each.account_name
  resource_group_name      = each.value.resource_group_name
  location                 = each.value.location
  account_tier             = each.value.account_tier
  account_replication_type = each.value.account_replication_type

  # use individual container_list as
  # some_attribute         = each.value.container.access_type

  }

You haven't provided code where you want to use containers_list , so I can only make comment above.