From my machine:
docker pull docker.elastic.co/beats/filebeat:6.6.2
Error response from daemon: unauthorized: authentication required
My cluster says:
filebeat-bp9cv 0/1 ImagePullBackOff 0 32m
This is happening in our production cluster. Seems as if the images were set as private. I guess we'll have to create proxy images of our own to avoid this in the future.