In AKS processing files on AKS node disk by application pod is not a recommended approach. It could lead to issues in stability of the AKS node itself. Therefore, we have two options. Either mount an Azure fileshare to the pod as described in "Mount Azure Storage Fileshare Created with Terraform on AKS". The other option is to setup a per pod disk, specially when the need is to process larger files. This option is really useful when we have pods running a single job and when it lives for the lifetime of the job. Example case is use of KEDA scale object with per single message processing from rabbitmq as described in "RabbitMQ KEDA Trigger for AKS Deployed Apps to Scale Out the Apps Accurately".
Expentation is to get a per pod disk attached as shown below.