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!

    • folekaule@lemmy.worldEnglish
      16·
      8 hours ago

      I know it’s ELI5, but this is a common misconception and will lead you astray. They do not have the same level of isolation, and they have very different purposes.

      For example, containers are disposable cattle. You don’t backup containers. You backup volumes and configuration, but not containers.

      Containers share the kernel with the host, so your container needs to be compatible with the host (though most dependencies are packaged with images).

      For self hosting maybe the difference doesn’t matter much, but there is a difference.

      • fishpen0@lemmy.worldEnglish
        5·
        4 hours ago

        A million times this. A major difference between the way most vms are run and most containers are run is:

        VMs write to their own internal disk, containers should be immutable and not be able to write to their internal filesystem

        You can have 100 identical containers running and if you are using your filesystem correctly only one copy of that container image is on your hard drive. You have have two nearly identical containers running and then only a small amount of the second container image (another layer) is wasting disk space

        Similarly containers and VMs use memory and cpu allocations differently and they run with extremely different security and networking scopes, but that requires even more explanation and is less relevant to self hosting unless you are trying to learn this to eventually get a job in it.