terraform迭代循环，但不是所有元素，而是特定元素

variable "servers" {
  type    = list(string)
  default = ["web1", "web2", "web3"]
}

resource "aws_instance" "server" {
  for_each = toset(var.servers)

  # 配置每个服务器的属性
  # ...
}

variable "buckets" {
  type = map(string)
  default = {
    "data"   = "private"
    "assets" = "public"
  }
}

resource "aws_s3_bucket" "bucket" {
  for_each = var.buckets

  # 配置每个存储桶的属性
  # ...
}

resource "aws_instance" "server" {
  for_each = toset(var.servers)

  tags = {
    Name = each.key  # 使用键作为标签值
  }

  provisioner "remote-exec" {
    # 配置远程执行命令
    # ...
  }
}

output "public_ip_addresses" {
  value = {
    for server_name, server_instance in aws_instance.server :
    server_name => server_instance.public_ip
  }
}