Nginx in LXC/Proxmox...how to Fail2ban?
from iturnedintoanewt@lemm.ee to selfhosted@lemmy.world on 09 Sep 2024 11:34
https://lemm.ee/post/41808527

Hi guys!

Back in the day I used to have a VM holding nginx and all the crap exposed…and I did set it up with fail2ban. I moved away from it, as the OS upgrade was turning messy, and rebuilt onto an LXC container. How should I use fail2ban/iptables in order to protect/harden my LXC container/server? Do the same conditions apply, or will I have any limitations/issues due to the container itself?

Thanks!

#selfhosted

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Dran_Arcana@lemmy.world on 09 Sep 2024 11:55 next collapse

Fail2ban and containers can be tricky, because under the hood, you’ll often have container policies automatically inserting themselves above host policies in iptables. The docker documentation has a good write-up on how to solve it for their implementation

docs.docker.com/…/packet-filtering-firewalls/

For your usecase specifically: If you’re using VMs only, you could run it within any VM that is exposing traffic, but for containers you’ll have to run fail2ban on the host itself. I’m not sure how LXC handles this, but I assume it’s probably similar to docker.

The simplest solution would be to just put something between your hypervisor and the Internet physically (a raspberry-pi-based firewall, etc)

486@lemmy.world on 09 Sep 2024 17:00 collapse

No, it is not like Docker. You can treat an LXC container pretty much like a VM in most instances, including firewall rules. To answer the question, you can use fail2ban just like you had done in your VM, meaning you can run it inside the LXC container, where fail2ban can change the firewall rules of that container as it sees fit.

iturnedintoanewt@lemm.ee on 10 Sep 2024 06:13 collapse

Thanks I appreciate your reply… I have a bit of concern about an unprivileged container having firewall limitations (as I might have read in the past this was…finicky), but I’m going to give it a shot.

486@lemmy.world on 10 Sep 2024 09:09 next collapse

I’m exclusively running unprivileged LXC containers and haven’t had any issues regarding the firewall, neither with iptables nor nftables.

K3can@lemmy.radio on 10 Sep 2024 23:41 collapse

I’ve also been running nginx in an unprivileged LXC container. I haven’t used fail2ban, specifically, but crowdsec has been working without issue.

You can mostly just treat an LXC like a normal VM.

Decronym@lemmy.decronym.xyz on 10 Sep 2024 23:45 collapse

Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I’ve seen in this thread:

Fewer Letters More Letters
HTTP Hypertext Transfer Protocol, the Web
LXC Linux Containers
nginx Popular HTTP server

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