Azure: "AKS" vmType no longer works

[jackfrancis]

Which component are you using?:

cluster-autoscaler

What version of the component are you using?:

Component version: 1.27.2

What k8s version are you using (kubectl version)?:

kubectl version Output

$ kubectl version
Server Version: version.Info{Major:"1", Minor:"27", GitVersion:"v1.27.3", GitCommit:"8b6cfe2c7c54ae110e0c2dbcc52b468bc08bf5f6", GitTreeState:"clean", BuildDate:"2023-07-28T22:18:46Z", GoVersion:"go1.20.5", Compiler:"gc", Platform:"linux/amd64"}

What environment is this in?:

Azure AKS

What did you expect to happen?:

I expect to be able to install the cluster-autoscaler runtime w/ a vmType configuration of "AKS" on an AKS cluster

What happened instead?:

Configured node pools are not identified for proper scaling

How to reproduce it (as minimally and precisely as possible):

$ helm install cluster-autoscaler cluster-autoscaler --repo https://kubernetes.github.io/autoscaler --set cloudProvider=azure --set autoscalingGroups[0].name=<name of pool>,autoscalingGroups[0].maxSize=100,autoscalingGroups[0].minSize=1 --set azureClientID=$TEST_AZURE_SP_ID --set azureClientSecret=$TEST_AZURE_SP_PW --set azureSubscriptionID=$TEST_AZURE_SUB_ID --set azureTenantID=$TEST_AZURE_TENANT_ID --set azureResourceGroup=<name of resource group> --set azureNodeResourceGroup=<name of node resource group> --set azureVMType=AKS --set azureClusterName=<name of AKS cluster>

Anything else we need to know?:

[jackfrancis]

/assign

[jackfrancis]

Here are the relevant log messages that indicate that the cluster-autoscaler runtime is not able to properly bootstrap itself for node pools w/ the "AKS" vmType:

I1011 23:50:44.395284       1 azure_cache.go:329] FindForInstance: starts, ref: azure:///subscriptions/<redacted>/resourceGroups/mc_francis-aks-test_francis-aks-test_eastus/providers/Microsoft.Compute/virtualMachineScaleSets/aks-nodepool2-26139306-vmss/virtualMachines/191
...
I1011 23:50:44.395344       1 azure_cache.go:369] FindForInstance: Couldn't find node group of instance {"azure:///subscriptions/<redacted>/resourceGroups/mc_francis-aks-test_francis-aks-test_eastus/providers/Microsoft.Compute/virtualMachineScaleSets/aks-nodepool2-26139306-vmss/virtualMachines/191"}
...
W1011 23:50:44.904213       1 clusterstate.go:647] Readiness for node group nodepool2 not found
W1011 23:50:44.904297       1 static_autoscaler.go:921] Couldn't find template for node group nodepool2
...
W1011 23:50:44.905331       1 clusterstate.go:397] Failed to find readiness information for nodepool2
W1011 23:50:44.905359       1 clusterstate.go:459] Failed to find readiness information for nodepool2
W1011 23:50:44.905363       1 clusterstate.go:397] Failed to find readiness information for nodepool2

[jackfrancis]

@gandhipr let me know if there's anything else we can document as part of proving that this doesn't work

Also let me know if my testing is incorrect.

Thanks!

[Shubham82]

/area provider/azure