将安全组附加到我的 aws 实例的 Terraform 问题

Question

我对 terraform 还不够新，我认为我误解了 count 和 count.index 用法。

我正在使用 count 参数创建一些 EC2 实例，它工作正常

resource "aws_instance" "server" {
ami = data.aws_ami.app_ami.id
instance_type = "t2.micro"
key_name = "DeirdreKey"
subnet_id = aws_subnet.my_subnet_a.id
count = 2
tags = {
 Name = "server.${count.index}"
}

我想将一个安全组与两个实例相关联，所以我创建了以下

resource "aws_network_interface_sg_attachment" "sg_attachment" {
security_group_id    = aws_security_group.allow_internet.id
network_interface_id = aws_instance.server.primary_network_interface_id
}

但是我遇到了这个错误

Error: Missing resource instance key

on lb.tf line 57, in resource "aws_network_interface_sg_attachment" "sg_attachment":
57:   network_interface_id = aws_instance.server.primary_network_interface_id

Because aws_instance.server has "count" set, its attributes must be
accessed on specific instances.

For example, to correlate with indices of a referring resource, use:
aws_instance.server[count.index]

我了解错误在抱怨什么。这是因为我所指的本地资源名称不是唯一的，因为我创建了 2 个称为“服务器”的 aws 实例。我不知道如何解决它。我尝试了以下

resource "aws_network_interface_sg_attachment" "sg_attachment" {
security_group_id    = aws_security_group.allow_internet.id
network_interface_id = aws_instance.server[count.index].primary_network_interface_id

然后我得到以下错误

Error: Reference to "count" in non-counted context

on lb.tf line 53, in resource "aws_network_interface_sg_attachment" "sg_attachment":
53:   network_interface_idaws_instance.server[count.index].primary_network_interface_id

The "count" object can only be used in "module", "resource", and "data"
blocks, and only when the "count" argument is set.

这是否意味着我必须将 count.index 引入本地资源名称？试了好几种方法都没有效果

resource "aws_instance" "server${count.index}" {

Answer 1

您需要对资源的计数语句才能使用count.index。计数语句可能会失控，因此如果您有多个在逻辑上需要相同计数的资源，请使用变量或局部值：

local {
  replications = 2
}

resource "aws_instance" "server" {
  count = local.replications
  ami = data.aws_ami.app_ami.id
  instance_type = "t2.micro"
  key_name = "DeirdreKey"
  subnet_id = aws_subnet.my_subnet_a.id
  tags = {
    Name = "server.${count.index}"
  }
}

resource "aws_network_interface_sg_attachment" "sg_attachment" {
  count                = local.replications
  security_group_id    = aws_security_group.allow_internet.id
  network_interface_id = aws_instance.server[count.index].primary_network_interface_id
}

这会为每台服务器创建一个安全组附件，并为您提供可以引用为 aws_instance.server[0] 和 aws_instance.server[1] 的服务器列表，以及可以以相同方式引用的附件列表。