How to use the each.key value as a variable name

Terraform
1

I want to pass in a list of strings that are table names I’m going to create in a module. The table definitions will be in a file in the subfolder where the module is. So my module will look something like this:

module "parquet_tables" {
    source    = "./create_table"
    table_names = [ "tab1", "tab2" ]
    providers = {
        aws 
  }
}

Then in a file in the subfolder I will have definitions in locals for each table:

locals {
  tab1 = {
    table_name = "table 1"
    table_description = ....
    s3_location = "s3://....
    database_name ="dbname"
.
.  }
}

Then in my create_table I want to iterate through the table_names list and create each table with for_each:

resource "aws_glue_catalog_table" "tablex" {
  provider = aws
  for_each = toset(var.table_names)
  name          = local.${each.key}.table_name
  database_name = local.${each.key}.database_name

This doesn’t work of course - it tells me an attribute name is required after the “local.” How can I get that string value of each table name I pass in as a table name to reference the local value of the same name?

1 Like
2

Did you ever manage to figure this out?

3

It is impossible, Terraform doesn’t support dynamic access to arbitrary locals.

Though, if you refactored it so it was instead dynamic access to keys within a map/object value, that was itself stored in a single local, that could work.

4

You should be able to do something like this (not tested):

locals {
  tables = {
    "tab1" = {
      table_name = "tab1"
      table_description = "..."
      s3_location = "s3://..."
      database_name ="dbname"
    }
    "tab2" = {
      # ...
    }
  }
}

resource "aws_glue_catalog_table" "tablex" {
  provider = aws
  for_each = toset(var.table_names)
  name          = local.tables[each.key].table_name
  database_name = local.tables[each.key].database_name
}