Terraform Variables

 Variables :

We are going to call these variables because you want to hold variables are they are a way of setting a value that we can use multiple times.

String:

variable "vpcname" {

  type = string

  default = "myvpc"

}

 How to Use Strings

resource "aws_vpc" "myname" {

  cidr_block = "10.0.0.1/16"

  tag {

    Name = var.vpcname

  }

}

number: 

variable "sshport" {

  type = number

  default = 22 

}

Note: number or integers don't go in double quote.

Boolen

variable "enabled" {

  default = true

}

#list

It can be store one type of data(string or boolean).

so this example I am going to use string. Arrays or list, there's an order.Its allow start with zero.

variable "mylist" {

  type = list()

  default = ["value1", "value2"]

}

example:

 How to Use Strings

resource "aws_vpc" "myname" {

  cidr_block = "10.0.0.1/16"

  tag {

    Name = mylist[]

  }

}

#Input

Input variables serve as parameters for a Terraform module.

Input variables are like function arguments.

Output values are like function return values.

Local values are like a function's temporary local variables.

variable "image_id" {

  type        = string

  description = "The id of the machine image (AMI) to use for the server."

}

#map

Map is key value pair.

variable "mymap" {

  type = map

  default = {

    key1 = "value1"

key2 = "value2"

}

resource "aws_vpc" "myname" {

  cidr_block = "10.0.0.1/16"

  tag {

    Name = var.map["key1"]

  }

}