Terraform Tutorials: Variables Complete Reference

In Terraform, there are several types of variables that you can define, including:

1. String: A sequence of characters. Example: “hello”.
2. Number: A numeric value. Example: 42.
3. Boolean: A logical value that is either true or false.
4. List: A sequence of values of the same type. Example: [ “apples”, “oranges”, “bananas” ].
5. Map: A collection of key-value pairs, where the keys and values can be of any type. Example: { “name” = “John”, “age” = 30 }.
6. Object: A complex data type that can contain multiple attributes. Example: { name = “John”, age = 30, address = { street = “123 Main St”, city = “Anytown”, state = “CA” } }.
7. Tuple: A sequence of values of different types. Example: [ “John”, 30, true ].

Quick Tutorials on Terraform Variable

Terraform Variables and Configuration explained – 5 mins reading!

Terraform Variable Naming convention

Types of Terraform variable

• Types of Terraform variable – Number
• Types of Terraform variable – String
• Types of Terraform variable – List
• Types of Terraform variable – Map
• Types of Terraform variable – Boolean

Location of Declaring Terraform Variable

• Environment Variables
• Local Values
• Command Line
• terraform.tfvars
• anyotherfile.tfvars
• Terrform Outout Variable
• Example of terraform terraform.tfvars
• Terraform Environment Variables Exaplained!

One Example Code

variable "instance_count" {
  type = number
  default = 1
}

variable "instance_name" {
  type = string
  default = "Rajesh"
}

resource "aws_instance" "example-number" {
  count = var.instance_count
  ami           = "ami-053b0d53c279acc90"
  instance_type = "t2.micro"
  
  tags = {
    Name = var.instance_name
  }
}


variable "security_groups" {
  type = list(string)
  default = ["sg-0541801a7a059ba17"]
}


resource "aws_instance" "example-list" {
  ami           = "ami-053b0d53c279acc90"
  instance_type = "t2.micro"
  vpc_security_group_ids = var.security_groups
}

variable "instance_tags" {
  type = map(string)
  default = {
    Name = "my-instance4mMap-Rajesh"
  }
}

resource "aws_instance" "example-map" {
  ami           = "ami-053b0d53c279acc90"
  instance_type = "t2.micro"
  tags = var.instance_tags
}

variable "create_vm" {
  description = "If set to true, it will create vm"
   type   = bool
}

resource "aws_instance" "example-bool" {
  count   = var.create_vm ? 1 : 0
  ami           = "ami-053b0d53c279acc90"
  instance_type = "t2.micro"
  tags = var.instance_tags
}Code language: PHP (php)

Rajesh Kumar

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