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!
PKI.
Apt and most release signing has a root of trust shipped with the OS and the PGP keys are cross signed on keyservers (web of trust).
DCT is just TOFU. They disable it because it gives a false sense of security. Docker is just not safe. Maybe on 10 years they'll fix it, but honestly it seems like they just dont care. The well is poisoned. Avoid. Use apt or some package manager that actually cares about security
So, if I understand correctly: rather than using prebuilt images from Docker Hub or untrusted sources, the recommended approach is to start from a minimal base image of a known OS (like Debian or Ubuntu), and explicitly install required packages via apt within the Dockerfile to ensure provenance and security. Does that make sense?
Install the package with apt. Avoid docker completely.
If the docker image maintainer has a github, open a ticket asking them to publish a Debian package
I see your point about trusting signed Debian packages, and I agree that’s ideal when possible. But Docker and APT serve very different purposes — one is for OS-level package management, the other for containerization and isolation. That’s actually where I got a bit confused by your answer — it felt like you were comparing tools with different goals (due to my limited knowledge). My intent isn’t just to install software, but to run it in a clean, reproducible, and isolated environment (maybe more than one in the same hosting machine). That’s why I’m considering building my own container from a minimal Debian base and installing everything via apt inside it, to preserve trust while still using containers responsibly! Does this makes sense for you? Thank you again for wasting your time to reply to my dumb messages
Containers have been around for decades. Look into lxc.
But for the best security, you want VMs. Look into proxmox.
Thank you man! I will look further into that