variables

Introduction

Terraform variables are placeholders for values that you can use to make your configurations more dynamic and reusable

Differnet types for terraform variables are below

• String - stores text values
• Number - numeric values
• Bool - short for boolean (true, false)
• List - sequence of values of same type
• Maps - collection of key-value pairs, each unique key map to specific values.
• Tuple - similar to list but can contain fixed number of elements.
• Object - used to define structure with named attributes
• Set - collections of unique values of the same type.

Local variables

Local variables are decalred using the locals block. It is a group of key-value pairs that can be used in the configuration. The values can be hard-coded or be a refernce to another variable or resource. It isaccessible within the module/configuration where they declared.

Example -

locals {
    ami  = "ami-0d26eb3972b7f8c96"
    type = "t2.micro"
    tags = {
        Env = "Dev"
    }
    subnet = "subnet-76a8163a"
    nic = aws_network_interface.my_nic.id
}

resoufce "aws_instance" "myvm" {
    ami = local.ami
    instance_type = local.type
    tags = local.tags
    network_interface{
        network_interface_id = local.nic
        device_index = 0
    }
}

resource "aws_network_interface" "my_nic" {
    description = "My NIC"
    subnet_id = var.subnet
}