如何通过Terraform将Azure负载均衡器从Basic SKU升级至Standard SKU？

问题描述 #

Azure门户提示：负载均衡器使用的Basic SKU将于2025年9月30日停用，需升级至Standard SKU，以下是当前的Terraform代码：

resource "azurerm_lb" "foo" {
  name = "foo-${var.URL_NAME}"

  frontend_ip_configuration {
    name                 = "PublicIPAddress"
    public_ip_address_id = azurerm_public_ip.foo_lb_ip.id
  }

   location            = var.AZURE_REGION
  resource_group_name = data.azurerm_resource_group.foo.name
}

resource "azurerm_lb_backend_address_pool" "foo" {
  name            = "BackEndAddressPool"
  loadbalancer_id = azurerm_lb.foo.id
}

resource "azurerm_network_interface_backend_address_pool_association" "foo" {
  count                   = var.NUMBER_OF_VMS
  backend_address_pool_id = azurerm_lb_backend_address_pool.foo.id
  ip_configuration_name   = "internal"
  network_interface_id    = azurerm_network_interface.foo[count.index].id
}

resource "azurerm_lb_probe" "foo" {
  name            = "foo-${var.URL_NAME}"
  protocol        = "Tcp"
  port            = 9999
  loadbalancer_id = azurerm_lb.foo.id
}

resource "azurerm_lb_rule" "foo" {
  name                           = "foo-${var.URL_NAME}"
  protocol                       = "Tcp"
  frontend_port                  = 9999
  backend_port                   = 9999
  frontend_ip_configuration_name = azurerm_lb.foo.frontend_ip_configuration[0].name
  loadbalancer_id                = azurerm_lb.foo.id
  backend_address_pool_ids       = [azurerm_lb_backend_address_pool.foo.id]
}

resource "azurerm_public_ip" "foo_lb_ip" {
  name                = "foo-lb-ip"
  allocation_method   = "Dynamic"
  location            = var.AZURE_REGION
  resource_group_name = data.azurerm_resource_group.foo.name
}

修改步骤 #

要升级至Standard SKU，需要对代码做以下关键修改：

1. 为负载均衡器指定Standard SKU
   在azurerm_lb资源中添加sku = "Standard"配置项：

resource "azurerm_lb" "foo" {
  name = "foo-${var.URL_NAME}"
  sku  = "Standard" # 指定Standard SKU

  frontend_ip_configuration {
    name                 = "PublicIPAddress"
    public_ip_address_id = azurerm_public_ip.foo_lb_ip.id
  }

  location            = var.AZURE_REGION
  resource_group_name = data.azurerm_resource_group.foo.name
}

2. 将公共IP升级为Standard SKU
   Standard负载均衡器要求配套的公共IP也必须是Standard SKU，因此修改azurerm_public_ip资源：

resource "azurerm_public_ip" "foo_lb_ip" {
  name                = "foo-lb-ip"
  allocation_method   = "Dynamic"
  sku                 = "Standard" # 指定Standard SKU
  location            = var.AZURE_REGION
  resource_group_name = data.azurerm_resource_group.foo.name
}

3. 验证其他资源兼容性
   现有后端地址池、网卡关联、探针和规则配置均兼容Standard SKU，无需额外修改，但需注意：

• Standard LB支持HA端口、出站规则等高级特性，可根据业务需求扩展配置
• 执行terraform plan预览变更，确认资源替换逻辑无误后，再执行terraform apply完成升级

注意事项 #

• 升级前确认所有关联资源（VM、网卡等）状态正常
• 建议备份当前Terraform状态文件，避免变更风险
• Standard SKU负载均衡器计费模式与Basic不同，需提前确认成本影响

内容的提问来源于stack exchange，提问作者Marcin Kulik