Using Terraform local variables in resource with for_each

Terraform
1

Hi, I need help in knowing how can I use local variable with multiple key and values to a resource using for_each, I have created Subnets Dynamically using Map variable and far each with Module. Now I want to create Interfaces which is into different module, I need subnet-id to be used from vpc module to the ec2 module for multiple interface creations.
Below are the code:

#CSR Interfaces Creation
resource "aws_network_interface" "csr_inf" {
    for_each = local.interface
  subnet_id       = each.value.inf_subnet_id
  private_ips     = [each.value.inf_private_ip]
  security_groups = [aws_security_group.vpn_role_csr.id]

  tags   = { "Name" = format("%s-%s", var.vpc_name, each.value.inf_name) }
}

Local Variable into Variables.tf file

locals {
    interface = {
        "CSR1000-Ext" = {
            inf_subnet_id    = module.csr_vpn_vpc.subnet_id.sub-1
            inf_private_ip   = "192.168.0.11"
            inf_name         = "CSR1000-External"
        },
        "CSR1001-Ext" = {
            inf_subnet_id    = module.csr_vpn_vpc.subnet_id.sub-2
            inf_private_ip   = "192.168.0.141"
            inf_name         = "CSR1001-External"
        },
    }
}

I am getting below error:

Error: Unsupported attribute

  on ../aws-modules/ec2/instances/main.tf line 67, in resource "aws_network_interface" "csr_inf":
  67:   subnet_id       = each.value.inf_subnet_id
    |----------------
    | each.value is "subnet-03e29c398eaf41c62"

This value does not have any attributes.


Error: Unsupported attribute

  on ../aws-modules/ec2/instances/main.tf line 67, in resource "aws_network_interface" "csr_inf":
  67:   subnet_id       = each.value.inf_subnet_id
    |----------------
    | each.value is "CSR1000-External"

This value does not have any attributes.


Error: Unsupported attribute

  on ../aws-modules/ec2/instances/main.tf line 67, in resource "aws_network_interface" "csr_inf":
  67:   subnet_id       = each.value.inf_subnet_id
    |----------------
    | each.value is "192.168.0.11"

This value does not have any attributes.


Error: Unsupported attribute

  on ../aws-modules/ec2/instances/main.tf line 68, in resource "aws_network_interface" "csr_inf":
  68:   private_ips     = [each.value.inf_private_ip]
    |----------------
    | each.value is "subnet-03e29c398eaf41c62"

This value does not have any attributes.

Any Idea how can I call Local variable value to the resource section using for_each?
Since Variable interpolation is not supported in terraform, we can’t use Variable input in this scenario as I need subnet-id to be called from the module output.

Any help on this will be appreciated.
Thanks

2

Hi @santossahani,

If the locals are defined as shown here, the aws_network_interface configuration looks valid. The errors indicate that local.interface is a collection of strings, rather than the objects shown here. Are you certain this is the exact config you are attempting to use?