Issue while updating AKS cluster with deprecated control and data plane

Question

I have an aks cluster with :

• k8s 1.19.13 on the controle plane
• k8s 1.17.13 on the data plane

I need to update the controle plane as <1.20 will no longer be supported, but I can't:

• If I update the controle plane, it ask me to upgrade the dataplane first, as only 2 minor version bellow can be supported (1.17+2<1.20).
  
• So I try to update the data plane first, but I can't as 1.19 is no longer supported, it prevent me from upgrading the nodes...
  

I'm stuck in this situation and don't know how to upgrade neither the control plane or data plane...

Answer 1

Hello @Sylvain Barbot ,
In these scenarios , please use Azure CLI command to upgrade the cluster:
az aks upgrade --resource-group resourcegroupname --name aksclustername --kubernetes-version versionnumber

Answer 2

Going with the cli, I was able to upgrade my dev cluster, I'm currently doing my production cluster but I suppose it will work too :-)
Thank you for the support.