Fix issue with default_node_pool min/max counts + update documentation

[adback03]

The max/min counts in the default node pool should be in the range of 0 to 100, not 1 and 100. This is a similar issue to that of #6020, but was never fixed for the default node pool.

I have also updated both sets of documentation to reflect these changes.

One minor update I snuck in this PR as well is just fixing the documentation for vnet_subnet_id. It is not required.

EDIT: This is potentially related to #6094 as well.

[tombuildsstuff]

hey @adback03

Thanks for this PR :)

That the min_count and max_count fields of the azurerm_kubernetes_cluster_node_pool resource can be set to 0 is actually a bug we're intending to fix in the v2.5 release - the root-cause of this being this error message here, where this value should be set to null rather than 0 (and this confusion stems from the error message being incorrect).

There's recently been some breaking changes in the AKS API - meaning that unfortunately we're going to have to include some breaking changes in the v2.5 release of the Azure Provider - as such we're going to take this opportunity to fix this bug and require that this field is set to null in both the azurerm_kubernetes_cluster and azurerm_kubernetes_cluster_node_pool resources (and fix the error messages).

These values can be set conditionally using null rather than 0 like so:

locals {
  enable_auto_scale = false
  fixed_count = 2
  min_count   = 1
  max_count   = 4
}

resource "azurerm_kubernetes_cluster_node_pool" "test" {
  # ...
  enable_auto_scaling = local.enable_auto_scale
  node_count          = local.enable_auto_scale ? null : local.fixed_count
  min_count           = local.enable_auto_scale ? local.min_count : null
  max_count           = local.enable_auto_scale ? local.max_count : null
}

As such whilst I'd like to thank you for this contribution, since we're looking to take a different approach here I'm going close this PR for the moment - however the changes to the vnet_subnet_id field look good, so to be able to get that in I hope you don't mind but I'm going to pull that change into the other (upcoming) PR so that we can ship that fix.

Thanks!

[ghost]

This has been released in version 2.5.0 of the provider. Please see the Terraform documentation on provider versioning or reach out if you need any assistance upgrading. As an example:

provider "azurerm" {
    version = "~> 2.5.0"
}
# ... other configuration ...

[ghost]

I'm going to lock this issue because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active issues.

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