Azure Windows函数应用与部署槽App-Settings互换问题求助

我通过GitLab-CI流水线，用Terraform AzureRM 3.66部署Azure Windows函数应用。部署后发现主函数应用的App-Settings跑到了部署槽里，而部署槽的App-Settings反而到了主应用上。之后我单独执行槽交换命令az functionapp deployment slot swap -g MyResourceGroup -n MyUniqueApp --slot staging --target-slot production，结果还是出现主应用和槽的设置互换的问题。

示例Terraform代码如下：

resource "azurerm_windows_function_app" "example" {
  name                 = "example-windows-function-app"
  resource_group_name  = azurerm_resource_group.example.name
  location             = azurerm_resource_group.example.location
  storage_account_name = azurerm_storage_account.example.name
  service_plan_id      = azurerm_service_plan.example.id

  app_settings = {
    "FUNCTIONS_WORKER_RUNTIME" = "dotnet"
    "SOME_APP_SETTING_KEY"    = "main-func-value"
    "ANOTHER_APP_SETTING_KEY" = "main-func-value"
  }
}

resource "azurerm_windows_function_app_slot" "example" {
  name                 = "example-slot"
  function_app_id      = azurerm_windows_function_app.example.id
  storage_account_name = azurerm_storage_account.example.name

  app_settings = {
    "FUNCTIONS_WORKER_RUNTIME" = "dotnet"
    "SOME_APP_SETTING_KEY"    = "staging_value"
    "ANOTHER_APP_SETTING_KEY" = "staging_another_value"
  }
}

1. Terraform未标记槽专属设置：默认情况下，Azure会把所有未标记为"槽特定"的App-Settings视为可交换项。你的代码里没配置slot_config_names，导致Terraform部署时，主应用和槽的设置没有明确区分，部署过程中就会出现互相覆盖的情况。
2. 槽交换命令的默认行为：az functionapp deployment slot swap默认会交换所有非槽特定的设置，就算你单独执行交换命令，这些未标记的设置还是会被互相替换。

1. 在Terraform中配置槽专属设置 #

通过slot_config_names字段标记哪些App-Settings是槽专属的，这些设置不会在交换时被替换。修改后的代码示例：

resource "azurerm_windows_function_app" "example" {
  name                 = "example-windows-function-app"
  resource_group_name  = azurerm_resource_group.example.name
  location             = azurerm_resource_group.example.location
  storage_account_name = azurerm_storage_account.example.name
  service_plan_id      = azurerm_service_plan.example.id

  app_settings = {
    "FUNCTIONS_WORKER_RUNTIME" = "dotnet"
    "SOME_APP_SETTING_KEY"    = "main-func-value"
    "ANOTHER_APP_SETTING_KEY" = "main-func-value"
  }

  # 标记这些设置为槽专属，交换时不会被替换
  slot_config_names {
    app_setting_names = ["SOME_APP_SETTING_KEY", "ANOTHER_APP_SETTING_KEY"]
  }
}

resource "azurerm_windows_function_app_slot" "example" {
  name                 = "example-slot"
  function_app_id      = azurerm_windows_function_app.example.id
  storage_account_name = azurerm_storage_account.example.name

  app_settings = {
    "FUNCTIONS_WORKER_RUNTIME" = "dotnet"
    "SOME_APP_SETTING_KEY"    = "staging_value"
    "ANOTHER_APP_SETTING_KEY" = "staging_another_value"
  }
}

2. 修改槽交换命令的参数 #

如果不想交换任何App-Settings，可以在命令里加上--preserve-slot-settings参数，这样交换时会保留槽的原有设置：

az functionapp deployment slot swap -g MyResourceGroup -n MyUniqueApp --slot staging --target-slot production --preserve-slot-settings

如果只需要交换特定设置，比如运行时配置，可以用--app-settings-to-swap指定：

az functionapp deployment slot swap -g MyResourceGroup -n MyUniqueApp --slot staging --target-slot production --app-settings-to-swap "FUNCTIONS_WORKER_RUNTIME"

3. 调整流水线执行顺序 #

确保GitLab-CI里先完成Terraform的部署任务，等主应用和槽的设置都部署到位后，再执行槽交换命令，避免部署未完成就触发交换导致的异常。

内容的提问来源于stack exchange，提问作者Mukteswar Patnaik