Hi! Im new to self hosting. Currently i am running a Jellyfin server on an old laptop. I am very curious to host other things in the future like immich or other services. I see a lot of mention of a program called docker.
search this on The internet I am still Not very clear what it does.
Could someone explain this to me like im stupid? What does it do and why would I need it?
Also what are other services that might be interesting to self host in The future?
Many thanks!
EDIT: Wow! thanks for all the detailed and super quick replies! I've been reading all the comments here and am concluding that (even though I am currently running only one service) it might be interesting to start using Docker to run all (future) services seperately on the server!
Okay, so way back when, Google needed a way to install and administer 500 new instances of whatever web service they had going on without it being a nightmare. So they made a little tool to make it easier to spin up random new stuff easily and scriptably.
So then the whole rest of the world said "Hey Google's doing that and they're super smart, we should do that too." So they did. They made Docker, and for some reason that involved Y Combinator giving someone millions of dollars for reasons I don't really understand.
So anyway, once Docker existed, nobody except Google and maybe like 50 other tech companies actually needed to do anything that it was useful for (and 48 out of those 50 are too addled by layoffs and nepotism to actually use Borg / K8s/ Docker (don't worry they're all the the same thing) for its intended purpose.) They just use it so their tech leads can have conversations at conferences and lunches where they make it out like anyone who's not using Docker must be an idiot, which is the primary purpose for technology as far as they're concerned.
But anyway in the meantime a bunch of FOSS software authors said "Hey this is pretty convenient, if I put a setup script inside a Dockerfile I can literally put whatever crazy bullshit I want into it, like 20 times more than even the most certifiably insane person would ever put up with in a list of setup instructions, and also I can pull in 50 gigs of dependencies if I want to of which 2,421 have critical security vulnerabilities and no one will see because they'll just hit the button and make it go."
And so now everyone uses Docker and it's a pain in the ass to make any edits to the configuration or setup and it's all in this weird virtualized box, and the "from scratch" instructions are usually out of date.
The end
I'm an advocate of running all of your self-hosted services in a Docker container and even I can admit that this is completely accurate.
Incus (formerly LXC/D, on which Docker used to be based on) is on my to-learn list.
Docker is not.