gistfile1.txt

data "aws_instance" "xxx" {
  filter {
    name   = "tag:Name"
    values = ["xxx"]
  }
}

resource "aws_security_group" "xxx" {
  name   = "xxx"
  vpc_id = "${var.vpc_id}"
}

resource "aws_security_group_rule" "add_ons" {
  type      = "ingress"
  from_port = "80"
  to_port   = "80"
  protocol  = "tcp"

  cidr_blocks       = [
    "${data.aws_instance.public_ip}/32"
  ]
  
  security_group_id = "${aws.aws_security_group.id}"
}