Unable to add VMSS to Application Gateway backend pool

[Geoff Fish]

I did also raise an issue here: https://github.com/terraform-providers/terraform-provider-azurerm/issues/857 I'm asking here on the off chance someone might know a workaround?

I'm trying to create an Azure VMSS (azurerm_virtual_machine_scale_set), which instead of the default load balancer, has an Application Gateway (azurerm_application_gateway)

All builds ok, apart from when we build the vm scale set, I can;t figure out how we add the VMSS nodes into the application gateways backend pool...

It can be done successfully using azurerm_lb...

azurerm_virtual_machine_scale_set.network_profile.ip_configuration.load_balancer_backend_address_pool_ids = ["${azurerm_lb_backend_address_pool.bpepool.id}"]

But if I swap out the backend pool id for one used by azurerm_application_gateway I get the following error:

ag-beap is referencing resource of a wrong type. The Id is expected to reference resources of type loadBalancers/backendAddressPools.

Should there be another attribute under azurerm_virtual_machine_scale_set.network_profile.ip_configuration - Like application_gateway_backend_pools?

...or maybe there is another way to do this that I'm missing?

[Geoff Fish]

Looks like missing functionality, which will hopefully be added soon, as it exists in the API/SDK for AzureRM