Dockerman backup image during update

[primeval_god]

So i recently ran into an issue updating a docker container. The container is from the wilds of docker hub and I hadnt updated the container in a while. After updating I found that the application no longer worked and when i went to roll back i realized that the container provider only provides a latest tag. I ended up having to backout one build at a time until i found a working version. 

 

So my feature request is for a Dockerman option to "backup" the existing image when using the update button. How i imagine this workings is, when enabled and an update is triggered, Dockerman would tag the containers current image with something like "unraid-backup-(date)" then proceed with the update as normal. If the updated succeeded Dockerman would untag any previous backup tags (but not the latest). That way the previous container image is always available if an immediate revert is needed. 

 

It would also be nice if it could recreate the container from the older tag if the update failed, and provide a mechanism for manually deleting the backup image(s) but that could be an exercise for a future date.