To your first questions, well need to untangle a few thoughts wrapped into that.

Right now, http://your-server-ip:8096/ is plain HTTP. On your home network that's usually fine. Over the internet, you'd want HTTPS so passwords and stream data aren't sent in the clear.

Just opening a port on Docker only exposes it to your local network. It's not on the public internet unless you also forward the port on your router. So by default, only devices on your network can reach it.

From there is it secure? That's on Jellyfin. Using strong passwords and trusting Jellyfin is secure is as good as you can do here.

The reverse proxy is where you handle the https, and where you go from domain.com:8096 to jelly.domain.com

If using caddy for example, that looks like this somewhere in your caddyfile

jellyfin.yourdomain.com {

reverse_proxy localhost:8096

}

Your reverse proxy sits in front of your containers and routes traffic by hostname. You tell it: "when someone visits jellyfin.yourdomain.com, send them to the Jellyfin container on port 8096."

The other pieces you'll need:

DNS pointing jellyfin.yourdomain.com at your server's IP (public IP if accessing from outside, local IP if just at home) A TLS certificate so HTTPS works, Let's Encrypt is free, and Caddy gets them automatically with zero config (Nginx and Traefik can too, just more setup).

Also rputer port forwarding on 80 and 443 to make it accessible outside the house.

The last part there is the actual risky part. When you put a service on the open internet, bots from everywhere will find it instantly and begin running scripts to try to find a way in. With only this setup, again, the insecurity is Jellyfin. When an exploit drops, you need to be updated ASAP to stay on top of your security.

There are tons of ways to make this more secure. The easiest way would be tailscale/(wireguard). You basically install tailscale on every device that will connect to your server instead of opening your routers port. It keeps your device off the open internet but allows devices all on its tailscale VPN connect to it with the domain you setup.

You can achieve something similar using cloudflare tunnels. Your server runs a daemon that reaches out to cloudflare and it's served to the internet that way, friends access via normal URL, no extra download required.

Lastly the best but cost prohibitive option is to do it through a VPS. A virtual private server does what cloudflare does, basically, but you control it. If the money is not prohibitive, I strongly recommend this. When cloudflare goes down again (and it will go down again), you won't be beholden to their infrastructure being online to access your server.

Happy to clarify anything here. I wrote this response in 3 parts and rereading it it feels a little disjointed lol

Ah sneaky. You added a question.

The answer to is there somewhere you can learn about this? Yes and no. You will ultimately learn by doing for this stuff.

Comptia network+ study guides will have all this knowledge and more.

If you're all in, Hack The Box is a freemium platform (think codecademy but less hand-holdy) that isn't designed to teach you this, but will absolutely teach you this in the process. It is a platform for offensive and defensive cybersecurity. These things are covered as afterthoughts in bigger pictures, but it will (at least for folks who learn by doing) force you to familiarize yourself with it implicitly.

Otherwise as far as IPs and ports and containers, I can tell you all you need to know, because it ain't much. It feels confusing/overwhelming at first but everything individual slice of this stuff is pretty simple. It's just an absurd amount of knowledge. Just take baby steps and learn what you need to know to get done what you seek.

https://training.linuxfoundation.org/networking/

It seems they don't have anything on networking exactly, but maybe some of their stuff on container orchestration can be helpful https://training.linuxfoundation.org/full-catalog/?_sft_product_type=training&_sft_topic_area=cloud-containers

About the domains and reverse proxies, if you are testing or on local network reverse proxy or domain are not needed. If you want to access it outside of your network they make more sense.

But also for my services I use https://tailscale.com/ and that way I avoid dealing with domain and reverse proxies by instead just connecting to my local network remotely.