I am working on code to detect when I am running outdated images.
I already have written in a interface into daemon api as well as the v2 registry api. I can pull up the image manifest from the registry and I can examine the image my docker daemon is running.
What I can’t figure out is how I can compare if the two are identical. Given the information about the image+tag I have on my local machine how can I tell if that image+tag has been updated/different on the registry server?
I know many have suggested just doing a pull but I don’t want to risk disturbing/changing production servers. Being able to compare versions with the registry without the risk of making changes allows me to alert on out of date images and plan maintenance windows around them.