Conditionals, Functions & Loops

condition ? true_value : false_value

variable "environment" {
  default = "dev"
}
 
resource "aws_instance" "web" {
  ami           = "ami-0199ac7c9fbf9ed83"
  instance_type = var.environment == "prod" ? "t3.medium" : "t3.micro"
}

resource "aws_instance" "web" {
  ami           = "ami-0199ac7c9fbf9ed83"
  instance_type = "t3.micro"
  monitoring    = var.environment == "prod" ? true : false
}

variable "instance_types" {
  default = {
    dev  = "t3.micro"
    prod = "t3.medium"
  }
}
 
output "instance_type" {
  value = lookup(var.instance_types, "prod")
}

user_data = file("userdata.sh")

resource "aws_instance" "web" {
  count         = 3
  ami           = "ami-0199ac7c9fbf9ed83"
  instance_type = "t3.micro"
 
  tags = {
    Name = "server-${count.index}"
  }
}

output "instance_ids" {
  value = aws_instance.web[*].id
}

resource "aws_s3_bucket" "bucket" {
  for_each = toset(["dev", "qa", "prod"])
  bucket   = "${each.key}-bucket-demo"
}

resource "aws_instance" "server" {
  for_each      = toset(["frontend", "backend", "database"])
  ami           = "ami-0199ac7c9fbf9ed83"
  instance_type = "t3.micro"
 
  tags = {
    Name = each.key
  }
}