如何获取 Terraform 计数的值

Question

我需要在下面的 Terraform 代码中获取count ，以便可以在 bash 中编写条件语句。

这是terraform

resource "aws_instance" "kubernetes_master" {
  ami = "${var.ec2-ami}"
  count = 3
  instance_type = "${var.ec2-type}"
  key_name = "${aws_key_pair.public.key_name}"
  subnet_id = "${aws_subnet.kube-master-subnet.id}"
  vpc_security_group_ids = ["${aws_security_group.sg-kube-master-allow-ssh.id}"]
  associate_public_ip_address = true

  user_data = <<-EOF
              #!/bin/bash           

              # if count=0; then echo "done"; fi

              pwd
            EOF
}

所以如果count=0 ，我想打印done

我怎样才能做到这一点？

Answer 1

您可以在 user_data heredoc 中使用${count.index}来引用当前计数。

resource "aws_instance" "kubernetes_master" {
  ami = "${var.ec2-ami}"
  count = 3
  instance_type = "${var.ec2-type}"
  key_name = "${aws_key_pair.public.key_name}"
  subnet_id = "${aws_subnet.kube-master-subnet.id}"
  vpc_security_group_ids = ["${aws_security_group.sg-kube-master-allow-ssh.id}"]
  associate_public_ip_address = true

  user_data = <<-EOF
              #!/bin/bash           

              # if ${count.index} -eq 0; then echo "done"; fi

              pwd
            EOF
}

如果资源的总计数为 0，则不会创建 aws_instance 资源，也不会运行 user_data。