Terraform user data AWS EC2 instance intialization example with user_data field.

resource "aws_instance" "ec2_instance" {
  count                       = "${var.instance_count}"
  ami                         = "${data.aws_ami.ec2_amzn2_ami_hvm.id}"
  instance_type               = "${var.instance_type}"
  subnet_id                   = "${var.subnet_id}"
  associate_public_ip_address = true
  monitoring                  = false
  key_name                    = "${var.key_name}"
  availability_zone           = "${var.availability_zone}"
  vpc_security_group_ids      = ["${aws_security_group.ec2_security_group.id}"]
  #User data field
  user_data                   = "${file("${path.module}/install.sh")}"
  
  tags = {
    Name = "user-data-instance-example"
  }
}