I’m a retired Unix admin. It was my job from the early '90s until the mid '10s. I’ve kept somewhat current ever since by running various machines at home. So far I’ve managed to avoid using Docker at home even though I have a decent understanding of how it works - I stopped being a sysadmin in the mid '10s, I still worked for a technology company and did plenty of “interesting” reading and training.
It seems that more and more stuff that I want to run at home is being delivered as Docker-first and I have to really go out of my way to find a non-Docker install.
I’m thinking it’s no longer a fad and I should invest some time getting comfortable with it?
The main downside of docker images is app developers don’t tend to play a lot of attention to the images that they produce beyond shipping their app. While software installed via your distribution benefits from meticulous scrutiny of security teams making sure security issues are fixed in a timely fashion, those fixes rarely trickle down the chain of images that your container ultimately depends on. While your distributions package manager sets up a cron job to install fixes from the security channel automatically, with Docker you are back to keeping track of this by yourself, hoping that the app developer takes this serious enough to supply new images in a timely fashion. This multies by number of images, so you are always only as secure as the least well maintained image.
Most images, including latest, are piss pour quality from a security standpoint. Because of that, professionals do not tend to grab “off the shelve” images from random sources of the internet. If they do, they pay extra attention to ensure that these containers run in sufficient isolated environment.
Self hosting communities do not often pay attention to this. You’ll have to decide for yourself how relevant this is for you.