Hello people, I recently rented a vps server from OVH and I want to start hosting my own piefed instance and a couple other services. I am running debian 13 with docker, and I have nginx proxy manager almost set up. I want to set up subdomains so when I do social.my.domain it will go to my piefed instance, but how do I tell the machine to send piefed traffic to this subdomain and joplin traffic (for example) to another domain? Can I use nginx/docker natively for that or do I have to install another program. Thanks for the advice.


The job of a reverse proxy like nginx is exactly this. Take traffic coming from one source (usually port 443 HTTPS) and forward it somewhere else based on things like the (sub)domain. A HTTPS reverse proxy often also forwards the traffic as HTTP on the local machine, so the software running the service doesn’t have to worry about ssl.
Be sure to get yourself a firewall on that machine. VPSes are usually directly connected to the internet without NAT in between. If you don’t have a firewall, all internal services will be accessible, stuff like databases or the internal ports of the services you host.
What? Only when they are configured to listen on outside interfaces. Which, granted, they often are in default configuration, but when OP uses Docker on that host, chances are kinda slim that they run some rando unconfigured database directly. Which still would be password or authentication protected in default config.
I mean, it is never wrong slapping a firewall onto something, I guess. But OTOH those “all services will be exposed and evil haxxors will take you over” is also a disservice.
I’ve seen many default docker-compose configurations provided by server software that expose the ports of stuff like databases by default (which exposes it on all host interfaces). Even outside docker, a lot of software, has a default configuration of “listen on all interfaces”.
I’m also not saying “evil haxxors will take you over”. It’s not the end of the world to have a service requiring authentication exposed to the internet, but it’s much better to only expose what should be public.
Yep, fair. Those docker-composes which just forward the ports to the host on all interfaces should burn. At least they should make them 127.0.0.1 forwards, I agree.
What service would you recommenced for firewall. The firewall I use on my laptop is ufw, should I use that on the vps or is their a different service that works better?
Firewalld
sudo apt-get install firewalld systemctl enable --now firewalld # ssh on port 22 opened but otherwise most things blocked by default firewall-cmd --get-active-zones firewall-cmd --info-zone=public firewall-cmd --zone=public --add-port=1234/tcp firewall-cmd --runtime-to-permanentThere are some decent guides online. Also take a look in
/etc/firewalld/firewalld.confand see if you want to change anything. Pay attention to the part about Docker.You need to know about zones, ports, and interfaces for the basics. Services are optional. Policies are more advanced.
UFW works well, and is easy to configure. UFW is a great option if you don’t need the flexibility (and insane complexity) that manually managing iptables rules offers,
The main problem with UFW, besides being based on legacy iptables (instead of the modern nftables which is easier to learn and manage), is the config format. Keeping track of your changes over track is hard, and even with tools like ansible it easily becomes a mess where things can fall out of sync with what you expect.
Unless you need iptables for some legacy system or have a weird fetish for it, nobody needs to learn iptables today. On modern Linux systems, iptables isn’t a kernel module anymore but a CLI shim that actually interacts with the nft backend.
Misconfigured UFW resulting in getting pwned is very common. For example, with default settings, Docker will bypass UFW completely for incoming traffic.
I strongly recommend firewalld, or rawdogging nftables, instead of ufw.
There used to be limitations with firewalld but policies maturing and replacing the deprecated “direct” rules together with other general improvements has made it a good default choice by now.