I can't login to my azure container registry
In order to access ACR from AKS, you can use the underlying service principal. That said, you've to create a role assignment for the Service Principal as mentioned in this paragraph https://docs.microsoft.com/en-us/azure/container-registry/container-registry-auth-aks?toc=%2fazure%2faks%2ftoc.json#grant-aks-access-to-acr
Creating a role assignment for role Reader currently doesn't work. You've to create the assignment for the Owner role. (described in https://github.com/Azure/AKS/issues/76).
Keep in mind that K8s caches the token for a couple of minutes. It took 3-5 minutes on my cluster to work.