If I have a buggy app in a container that is constantly writing to an emptyDir volume it could use up all the space on the worker node and affect the performance of other pods / containers on the node. Thus breaking the expectation that containers are isolated from each other what one container does should not negatively impact other containers on the node.
Is there a way to limit the amount of disk space used by a emptyDir volume (not the RAM based emptyDir type)?
You can set sizeLimit on the volume (see https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.11/#emptydirvolumesource-v1-core). Setting this will, once the volume is full, evict the pod.