Terraform meta argument: count

• count meta argument

• count.index

Examples

• count = length(var.subnet_ids)
• count = var.vpc_cidr_block != null ? 1 : 0
• count = local.create_node_sg ? 1 : 0
• count = var.istest == true ? 3 : 0

• count = 0

Terraform does not allow to use count inside module block.

resource "aws_instance" "dev" {
   ami = "ami-082b5a644766e0e6f"
   instance_type = "t2.micro"
   count = 2
}

resource "aws_instance" "your_new_instance_in_test" {
   ami = "ami-082b5a644766e0e6f"
   instance_type = "t2.micro"
   count = var.istest == true ? 3 : 0
}

resource "aws_instance" "your_new_conditional_instance {
   count = var.your_env == "PRE" ? 1 : 0
   ami = "ami-082b5a644766e0e6f"
   instance_type = "t2.micro"
}

variable "elb_names" {
  type = list
  default = ["dev-loadbalancer", "stage-loadbalanacer","prod-loadbalancer"]
}
 
resource "aws_iam_user" "lb" {
  name = var.elb_names[count.index]
  count = 2
  path = "/system/"
}

resource "aws_ecs_service" "your_service" {
count = var.your_env_name == "PROD" ? 1 : 0
.../...
task_definition = "${aws_ecs_task_definition.dashboards_task[0].family}:${aws_ecs_task_definition.dashboards_task[0].revision}"
.../...
}

Error

• Error: Unexpected resource instance key
• Error: Missing resource instance key
• Error: Invalid index

Related

• for_each
• # aws_instance.your-instance-name has moved to aws_instance.your-instance-name[0]
• Terraform conditional expressions
• count.index

See also

• Terraform meta argument: count
• Terraform functions, Terraform collection functions: tolist, toset, length, sum, file, join, depends_on, zipmap, replace, lookup, read files, concat, merge, templatefile, for_each, format, element, slice, try, filebase64, upper, filemd5, coalesce
• Terraform: Meta-Arguments: count, depends_on, lifecycle: [ prevent_destroy | ignore_changes ]

https://www.terraform.io/docs/language/meta-arguments/count.html

https://registry.terraform.io/modules/terraform-aws-modules/s3-bucket/aws/latest