Terraform Azure中如何自动获取Host Pool列表的ID值

假设你已通过for_each批量创建Host Pool，比如：

resource "azurerm_virtual_desktop_host_pool" "host_pools" {
  for_each = {
    host_pool_security = "Security-Team-Pool"
    host_pool_finance  = "Finance-Team-Pool"
    host_pool_hr       = "HR-Team-Pool"
  }

  name                = each.value
  location            = azurerm_resource_group.vd_rg.location
  resource_group_name = azurerm_resource_group.vd_rg.name
  type                = "Pooled"
  load_balancer_type  = "DepthFirst"
}

以下是两种自动获取所有Host Pool ID的方案：

方法1：直接提取所有ID列表 #

用values()函数遍历批量创建的资源实例，提取所有id属性生成列表：

locals {
  all_host_pool_ids = values(azurerm_virtual_desktop_host_pool.host_pools)[*].id
}

关联应用组时直接引用这个局部变量即可，比如批量创建对应应用组：

resource "azurerm_virtual_desktop_application_group" "app_groups" {
  for_each = toset(local.all_host_pool_ids)

  name                = "AppGroup-${replace(each.value, "/", "-")}"
  location            = azurerm_resource_group.vd_rg.location
  resource_group_name = azurerm_resource_group.vd_rg.name
  type                = "RemoteApp"
  host_pool_id        = each.value
}

方法2：带筛选条件的灵活提取 #

如果需要筛选特定Host Pool（比如按键名前缀、资源属性），用for表达式自定义规则：

locals {
  filtered_host_pool_ids = [
    for key, pool in azurerm_virtual_desktop_host_pool.host_pools : pool.id
    if startswith(key, "host_pool_") # 按键名前缀筛选
    # 也可以按资源属性筛选，比如 if pool.type == "Pooled"
  ]
}

进阶：直接关联Host Pool与应用组 #

如果应用组需要和Host Pool一一对应，无需单独提取ID，直接复用Host Pool的for_each集合：

resource "azurerm_virtual_desktop_application_group" "app_groups" {
  for_each = azurerm_virtual_desktop_host_pool.host_pools

  name                = "${each.key}-app-group"
  location            = azurerm_resource_group.vd_rg.location
  resource_group_name = azurerm_resource_group.vd_rg.name
  type                = "RemoteApp"
  host_pool_id        = each.value.id
}

内容的提问来源于stack exchange，提问作者Hamma