I upgraded Harbor before, it was a pain. I think you're encouraged to use their official Helm chart and then it's supposed to be fairly seamless https://goharbor.io/docs/2.13.0/administration/upgrade/helm-... but if your predecessor decided against that option, separately adjusting the configuration for all the moving pieces is fairly annoying. Also, I misconfigured something and ended having to read Harbor source code because the error messages weren't very helpful. Fortunately, I had the presence of mind to first practice on a secondary installation created from a backup. It's definitely not something where you can stop production, install the update, and expect it to come back up in working order.