Azure Provider: Attaching Application Gateway to VM Scale Set

I’m having great difficulty attaching an Application Gateway backend pool to a VM Scale Set. I’m not getting any errors in TF plan / apply, but according to the Azure Portal, the VMSS IP config is not listed in the backend pool of the Application Gateway.

This is the only example I can find and I wonder if it is out-of-date.

Unfortunately the provider’ documentation doesn’t have an example of application gateway and this is referencing a block as opposed to a single attribute.

In my VMSS module, I am passing the ID thus:

application_gateway_backend_address_pool_ids = ["${module.app_gateway_example[0].id}/backendAddressPools/my-backend-address-pool"]

Can anyone point me to a working example, or let me know if the above is still correct.


P.S. Using TF 0.12.5 with AzureRM provider 1.31.0.