Azure Databricks workspace using terraform - terraform

Question

Trying to create Databricks workspace using terraform but unsupported arguments:
resource "azurerm_databricks_workspace" "workspace" {
name = "testdata"
resource_group_name = "cloud-terraform"
location = "east us"
sku = "premium"
virtual_network_id = azurerm_virtual_network.vnet.id
public_subnet_name = "databrickpublicsubnet"
public_subnet_cidr = "10.0.0.0/22"
private_subnet_name = "databrickprivatesubnet"
private_subnet_cidr = "10.0.0.0/22"
tags = {
Environment = "terraformtest"
}
}
Error: An argument named "virtual_network_id" is not expected here. An argument named "public_subnet_name" is not expected here. An argument named "public_subnet_cidr" is not expected here.

Answer 1

I haven't tried to set up databricks via Terraform, but I believe (per the docs) you need add those properties in a block:
resource "azurerm_databricks_workspace" "workspace" {
name = "testdata"
resource_group_name = "cloud-terraform"
location = "east us"
sku = "premium"
custom_parameters {
virtual_network_id = azurerm_virtual_network.vnet.id
public_subnet_name = "databrickpublicsubnet"
private_subnet_name = "databrickprivatesubnet"
}
tags = {
Environment = "terraformtest"
}
}
The two cidr entries aren't part of the TF documentation.

Answer 2

true. you can add terraform commands to create the subnets (assuming vnet already exists, you can use data azurerm_virtual_network then create the two new subnets, then reference the names of the two new public/private subnets.
Then you run into what seems to be a chicken/egg issue though.
You get Error: you must define a value for 'public_subnet_network_security_group_association_id' if 'public_subnet_name' is set.
Problem is, the network security group is typically auto-generated on creation of the databrick workspace (like databricksnsgrandomstring), which works when creating it in the portal, but via terraform, I have to define it to create the workspace, but it doesn't yet exist until I create the workspace. The fix is to not let it generate it's own nsg name, but name it yourself with an nsg resource block.
below is code I use (dbname means databricks name!). here I'm
adding to an existing resource group 'qa' and existing vnet as well, only showing the public subnet and nsg association, you can easily add the private ones). just copy/modify in your own tf file(s). and you'll definitely need to change the address_prefix to your own CIDR values that works within your vnet and not stomp on existing subnets within.
resource "azurerm_subnet" "public" {
name = "${var.dbname}-public-subnet"
resource_group_name = data.azurerm_resource_group.qa.name
virtual_network_name = data.azurerm_virtual_network.vnet.name
address_prefixes = ["1.2.3.4/24"]
delegation {
name = "databricks_public"
service_delegation {
name = "Microsoft.Databricks/workspaces"
}
}
}
resource "azurerm_network_security_group" "nsg" {
name = "${var.dbname}-qa-databricks-nsg"
resource_group_name = data.azurerm_resource_group.qa.name
location= data.azurerm_resource_group.qa.location
}
resource "azurerm_subnet_network_security_group_association" "nsga_public" {
network_security_group_id = azurerm_network_security_group.nsg.id
subnet_id = azurerm_subnet.public.id
}
Then in your databricks_workspace block, replace your custom parameters with
custom_parameters {
public_subnet_name = azurerm_subnet.public.name
public_subnet_network_security_group_association_id = azurerm_subnet_network_security_group_association.nsga_public.id
private_subnet_name = azurerm_subnet.private.name
private_subnet_network_security_group_association_id = azurerm_subnet_network_security_group_association.nsga_private.id
virtual_network_id = data.azurerm_virtual_network.vnet.id
}