乱读天书， 不求甚解

不会做任何操作的resource，用于存放数据

官方案例
用于版本控制

variable "revision" {
  default = 1
}
resource "terraform_data" "replacement" {
  input = var.revision
}
# This resource has no convenient attribute which forces replacement,
# but can now be replaced by any change to the revision variable value.
resource "example_database" "test" {
  lifecycle {
    replace_triggered_by = [terraform_data.replacement]
  }
}

用于触发脚本

resource "aws_instance" "web" {
  # ...
}
resource "aws_instance" "database" {
  # ...
}
# A use-case for terraform_data is as a do-nothing container
# for arbitrary actions taken by a provisioner.
resource "terraform_data" "bootstrap" {
  triggers_replace = [
    aws_instance.web.id,
    aws_instance.database.id
  ]
  provisioner "local-exec" {
    command = "bootstrap-hosts.sh"
  }
}