Terraform Error deleting App Service Plan StatusCode=409 Server farm [asp] cannot be deleted because it has web app(s) [azure-function] assigned to it

1
votes

I have an Azure Function and an Azure Service Plan that was both created using the following Terraform code:

resource "azurerm_app_service_plan" "asp" {
    name = "asp-${var.environment}"
    resource_group_name      = var.rg_name
    location                 = var.location
    kind = "FunctionApp"
    reserved            = true
    sku {
        tier = "ElasticPremium"
        size = "EP1"
    }
}

resource "azurerm_function_app" "function" {
    name = "function-${var.environment}"
    resource_group_name= var.rg_name
    location= var.location
    app_service_plan_id= azurerm_app_service_plan.asp.id
    storage_connection_string=azurerm_storage_account.storage.primary_connection_string
    os_type = "linux"


    site_config {
      linux_fx_version = "DOCKER|${data.azurerm_container_registry.acr.login_server}/${var.image_name}:latest"
    }

    identity {
      type = "SystemAssigned"
    }


    app_settings              = {
    #Lots of variables, but irrelevant for this issue I assume?
    }

    depends_on = [azurerm_app_service_plan.asp]
    version = "~2"

}

resource "azurerm_storage_account" "storage" {
  name                     = "storage${var.environment}"
  resource_group_name      = var.rg_name
  location                 = var.location
  account_tier             = "Standard"
  account_replication_type = "LRS"
}

The function works fine.

The issue is that any change I now try to do in Terraform ends up in the following error during apply:

2020-08-25T06:31:23.256Z [DEBUG] plugin.terraform-provider-azurerm_v2.24.0_x5: {"Code":"Conflict","Message":"Server farm 'asp-staging' cannot be deleted because it has web app(s) function-staging assigned to it.","Target":null,"Details":[{"Message":"Server farm 'asp-staging' cannot be deleted because it has web app(s) function-staging assigned to it."},{"Code":"Conflict"},{"ErrorEntity":{"ExtendedCode":"11003","MessageTemplate":"Server farm '{0}' cannot be deleted because it has web app(s) {1} assigned to it.","Parameters":["asp-staging","function-staging"],"Code":"Conflict","Message":"Server farm 'asp-staging' cannot be deleted because it has web app(s) function-staging assigned to it."}}],"Innererror":null}
...
Error: Error deleting App Service Plan "asp-staging" (Resource Group "my-resource-group"): web.AppServicePlansClient#Delete: Failure sending request: StatusCode=409 -- Original Error: autorest/azure: Service returned an error. Status=<nil> <nil>

I have another service plan with an app service, and have had no problems applying while they are running. I have even tried removing all references to the function and its service plan and still get the same error.

I am able to delete the Function and its service plan from the portal and then Terraform applies fine once when it create the function and service plan. As long as those are present when Terraform applies it fails.

This workaround of manually deleting the function and service plan is not feasible in the long run, so I hope someone can help me point out the issue. Is there some error in the way I have created the function or service plan?

provider "azurerm" {
  version = "~> 2.24.0"
...

Edit: As suggested this might be a provider bug, so I have created this issue: https://github.com/terraform-providers/terraform-provider-azurerm/issues/8241

Edit2: On the bug forum they claim it is a configuration error and that I am missing a dependency. I have updated the code with a depends_on, I still have the same error.

1
azureazure-functionsterraformazure-app-service-plans
this sounds more like a bug with the terraform provider, hence you should open an issue in the github repo. as a workaround, you could try to add an explicit depends_on to the function to see if this helps – silent
Sometimes I feel like it's a timing issue. Adding a null_resource declaring the dependnecy between app service and app plan with a short delay/sleep helps. – pijemcolu
Thanks pilemcolu, tested adding a 30 sec sleep between them with depends_on, and still same error – Stian
According to my knowloage, the service plan and the function app will be created sequencely without depends_on. So it's not necessary and not the issue. And you can delete them with the command terraform destroy without any problem. So I think the problem is your function app, maybe there is anything else wrong in it so that it cannot be delete and cause the error you got. – Charles Xu
Do you only assign the function app to the service plan? And if you can delete the function app in another way without any error? Or when you delete the function app you get the error? – Charles Xu

1 Answers

1
votes

I found the issue. On every apply the service plan was reapplied every time:

# azurerm_app_service_plan.asp must be replaced
-/+ resource "azurerm_app_service_plan" "asp" {
      ~ id                           = "/subscriptions/xxx/resourceGroups/xxx/providers/Microsoft.Web/serverfarms/asp" -> (known after apply)
      - is_xenon                     = false -> null
      ~ kind                         = "elastic" -> "FunctionApp" # forces replacement
        location                     = "norwayeast"
      ~ maximum_elastic_worker_count = 1 -> (known after apply)
      ~ maximum_number_of_workers    = 20 -> (known after apply)
        name                         = "asp"
      - per_site_scaling             = false -> null
        reserved                     = true
        resource_group_name          = "xxx"
      - tags                         = {
          - "Owner"       = "XXX"
          - "Service"     = "XXX"
          - "environment" = "staging"
        } -> null

Even though I created it as kind="FunctionApp" it seems it was changed to "elastic"

I now changed it to kind="elastic" and Terraform has stopped destroying my service plan on every apply :)

Thanks a lot to Charles Xu for lots of help!