When you create an AKS cluster, Azure also creates a service principal to support cluster operability with other Azure resources. You can use this auto-generated service principal for authentication with an ACR registry. To do so, you need to create an Azure AD role assignment that grants the cluster's service principal access to the container registry. References: https://docs.microsoft.com/bs-latn-ba/azure/container-registry/container-registry-auth-aks