if condition in terraform in count - terraform

Question

I am adding autoscale settings in the Azure cosmosdb database, My problem is not all our db requires autoscale only a selection of database require autoscalse rest are manual. I will not be able to specify the autoscalse block also the throughout in the same resource as there are conflicts between those two. so I thought of using the count but I will be not be able to run the resouece block for only one of the DB. for the below example
variable
variable "databases" {
description = "The list of Cosmos DB SQL Databases."
type = list(object({
name = string
throughput = number
autoscale = bool
max_throughput = number
}))
default = [
{
name = "testcoll1"
throughput = 400
autoscale = false
max_throughput = 0
},
{
name = "testcoll2"
throughput = 400
autoscale = true
max_throughput = 1000
}
]
}
For the first I dont need autoscale and next one I need. My main.tf code
resource "azurerm_cosmosdb_mongo_database" "database_manual" {
count = length(var.databases)
name = var.databases[count.index].name
resource_group_name = azurerm_cosmosdb_account.cosmosdb.resource_group_name
account_name = local.account_name
throughput = var.databases[count.index].throughput
}
resource "azurerm_cosmosdb_mongo_database" "database_autoscale" {
count = length(var.databases)
name = var.databases[count.index].name
resource_group_name = azurerm_cosmosdb_account.cosmosdb.resource_group_name
account_name = local.account_name
autoscale_settings {
max_throughput = var.databases[count.index].max_throughput
}
}
First I thought of running two blocks one with scale and on without, but I will not be able to proceed because it requires the count numbers
count = var.autoscale_required == true ? len(databases) : 0
at the start but in my case I will only know at the time of iteration. I have tried to use dynamic within the block but errored out.
*Update
I have switched to foreach and able to run the condition but still it requires 2 blocks
resource "azurerm_cosmosdb_mongo_database" "database_autoscale"
resource "azurerm_cosmosdb_mongo_database" "database_manual"
resource "azurerm_cosmosdb_mongo_database" "database_autoscale" {
for_each = {
for key, value in var.databases : key => value
if value.autoscale_required == true }
name = each.value.name
resource_group_name = azurerm_cosmosdb_account.cosmosdb.resource_group_name
account_name = local.account_name
autoscale_settings {
max_throughput = each.value.max_throughput
}
}

Answer 1

If I understand correctly, I think you could do what you want using the following:
resource "azurerm_cosmosdb_mongo_database" "database_autoscale" {
count = length(var.databases)
name = var.databases[count.index].name
resource_group_name = azurerm_cosmosdb_account.cosmosdb.resource_group_name
account_name = local.account_name
throughput = var.databases[count.index].autoscale == false ? var.databases[count.index].throughput : null
dynamic "autoscale_settings" {
for_each = var.databases[count.index].autoscale == false ? [] : [1]
content {
max_throughput = var.databases[count.index].max_throughput
}
}
}