Example of terraform issue

main.tf

provider "aws" {
  region = "${var.aws_region}"
}

variable "aws_region" {
  default = "eu-west-1"
}

variable "asg_max_size" {
  default = "6"
}

variable "asg_min_size" {
  default = "3"
}

variable "namespace" {
  default = "mps"
}

variable "component" {
  default = "foo"
}

variable "stage" {
  default = "rbtest"
}

locals {
  common_settings = [
    {
      namespace = "aws:autoscaling:asg"
      name      = "Availability Zones"
      value     = "Any"
    },
    {
      namespace = "aws:autoscaling:asg"
      name      = "Cooldown"
      value     = "360"
    },
  ]

  specific_settings = [
    {
      namespace = "aws:autoscaling:asg"
      name      = "MaxSize"
      value     = "${var.asg_max_size}"
    },
    {
      namespace = "aws:autoscaling:asg"
      name      = "MinSize"
      value     = "${var.asg_min_size}"
    },
    {
      namespace = "aws:autoscaling:launchconfiguration"
      name      = "IamInstanceProfile"
      value     = "${aws_iam_instance_profile.instance.name}"
    },
  ]
}

resource "aws_iam_instance_profile" "instance" {
  name = "instance_profile"
  path = "/"
  role = "${aws_iam_role.instance.name}"
}

resource "aws_iam_role" "instance" {
  name               = "ec2-role"
  path               = "/"
  assume_role_policy = "${data.aws_iam_policy_document.instance.json}"
}

data "aws_iam_policy_document" "instance" {
  statement {
    actions = [
      "sts:AssumeRole",
    ]

    effect = "Allow"

    principals {
      type        = "Service"
      identifiers = ["ec2.amazonaws.com"]
    }
  }
}

resource "aws_elastic_beanstalk_environment" "foo" {
  name                = "foo"
  application         = "foo_app"
  cname_prefix        = "foo"
  solution_stack_name = "64bit Amazon Linux 2017.03 v2.5.0 running PHP 7.1"
  tier                = "WebServer"
  setting             = "${concat(local.common_settings, local.specific_settings)}"
}