aks: support for ephemeral disks on default & custom node pools

[4c74356b41]

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Description

Add an ability to create node pools with ephemeral disks

New or Affected Resource(s)

• azurerm_kubernetes_cluster
• azurerm_kubernetes_cluster_node_pool

Potential Terraform Configuration

    default_node_pool {
        xxx
        os_disk_type = "Ephemeral" # or "Managed"
        xxx
    }

References

Azure/AKS#1370
https://github.com/Azure/azure-sdk-for-go/blob/master/services/containerservice/mgmt/2020-09-01/containerservice/models.go#L1379
https://docs.microsoft.com/en-us/rest/api/aks/agentpools/createorupdate#osdisktype

[davidack]

A big thumbs-up on this one, but please add kubernetes_cluster_node_pool to the affected resources.

For anyone not already aware, this problem can be worked around by creating a node pool with az aks nodepool add EnableEphemeralOSDisk=true then importing the newly created node pool into the Terraform state, but this is of course non-optimal.

[4c74356b41]

@davidack yeah, sorry, my bad, forgot about it

[ghost]

This has been released in version 2.37.0 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 = "~> 2.37.0"
}
# ... other configuration ...

[davidack]

Thanks all for getting this done, you are awesome!

[blafry]

As I can see support for os_disk_type was added only to kubernetes_cluster_node_pool resource. Thanks a lot for that!

But what about azurerm_kubernetes_cluster mentioned in first comment? default_node_pool should also support os_disk_type.

[mrowken]

According to AKS release notes Ephemeral OS is now GA and used as default.
Current behavior of azurerm_kubernetes_cluster makes it impossible to use this feature, because it always sets default_node_pool->os_disk_type = "Managed" and doesn't expose parameter to override.

Could you please prioritize this change or is there any particular reason for being missing ?

[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.

If you feel this issue should be reopened, we encourage creating a new issue linking back to this one for added context. If you feel I made an error 🤖 🙉 , please reach out to my human friends 👉 hashibot-feedback@hashicorp.com. Thanks!