[ISSUE] databricks_service_principal not accepting a "known after apply" application_id

[alex-davies]

databricks_service_principal is failing to validate the application_id if it is derived from a dependant resource (i.e. Known after apply).

When creating an azuread_application and databricks_service_principal in the same plan/apply, the databricks_service_principal fails to recognize an application_id has been set

if the azuread_application is applied first. Then the databricks_service_principal is applied separately. Then the issue does not occur

Configuration

data "azurerm_client_config" "current" {}

resource "azuread_application" "service" {
  display_name     = "my-ad-app"
  sign_in_audience = "AzureADMyOrg"
  owners           = [data.azurerm_client_config.current.object_id]
}

resource "databricks_service_principal" "service" {
  display_name          = azuread_application.service.display_name
  application_id        = azuread_application.service.application_id
}

Expected Behavior

1. Azure AD app is created
2. Databricks principal is created linked to the azure app

Actual Behavior

When planning an Error: application_id is required for service principals in Azure Databricks is output

Steps to Reproduce

This can be reproduced using a azure databricks. Error is produced when running terraform plan

Terraform and provider versions

Terraform v1.0.5
on windows_amd64
+ provider registry.terraform.io/databrickslabs/databricks v0.5.2
+ provider registry.terraform.io/hashicorp/azuread v2.18.0
+ provider registry.terraform.io/hashicorp/azurerm v2.96.0

[nfx]

@alex-davies Databricks Platform API on Azure will throw an error if application_id is not specified. can you build the provider locally and comment out these and see what happens:

https://github.com/databrickslabs/terraform-provider-databricks/blob/17a67b140bda8c54f095122f006051ce2cff832d/scim/resource_service_principal.go#L88-L91

well-tested PRs are welcome.