this post was submitted on 29 Aug 2025
546 points (99.1% liked)

Programmer Humor

26111 readers
519 users here now

Welcome to Programmer Humor!

This is a place where you can post jokes, memes, humor, etc. related to programming!

For sharing awful code theres also Programming Horror.

Rules

founded 2 years ago
MODERATORS
 

Docker docs:

Docker routes container traffic in the nat table, which means that packets are diverted before it reaches the INPUT and OUTPUT chains that ufw uses. Packets are routed before the firewall rules can be applied, effectively ignoring your firewall configuration.

top 50 comments
sorted by: hot top controversial new old
[–] veganpizza69@lemmy.vg 118 points 3 days ago
[–] Static_Rocket@lemmy.world 105 points 4 days ago (3 children)

This was a large part of the reason I switched to rootless podman for everything

[–] False@lemmy.world 21 points 4 days ago (2 children)

Explicitly binding certain ports to the container has a similar effect, no?

[–] doughless@lemmy.world 9 points 4 days ago (4 children)

I still need to allow the ports in my firewall when using podman, even when I bind to 0.0.0.0.

load more comments (4 replies)
load more comments (1 replies)
[–] Kr4u7@discuss.tchncs.de 10 points 4 days ago (4 children)

My problem with podman is the incompatibility with portainer :(

Any recommendations?

[–] giacomo@lemmy.dbzer0.com 14 points 4 days ago (2 children)

cockpit has a podman/container extension you might like.

load more comments (2 replies)
[–] slate@sh.itjust.works 12 points 4 days ago (1 children)

CLI and Quadlet? /s but seriously, that's what I use lol

load more comments (1 replies)
load more comments (2 replies)
load more comments (1 replies)
[–] Harbinger01173430@lemmy.world 13 points 3 days ago (1 children)

Nat is not security.

Keep that in mind.

It's just a crutch ipv4 has to use because it's not as powerful as the almighty ipv6

[–] dangling_cat@piefed.blahaj.zone 35 points 4 days ago (2 children)

I DIDNT KNOW THAT! WOW, this puts “not to use network_mode: host” another level.

[–] exu@feditown.com 17 points 4 days ago (1 children)

network: host gives the container basically full access to any port it wants. But even with other network modes you need to be careful, as any -p <external port>:<container port> creates the appropriate firewall rule automatically.

load more comments (1 replies)
load more comments (1 replies)
[–] dohpaz42@lemmy.world 32 points 4 days ago (3 children)

It’s my understanding that docker uses a lot of fuckery and hackery to do what they do. And IME they don’t seem to care if it breaks things.

[–] marcos@lemmy.world 31 points 4 days ago

To be fair, the largest problem here is that it presents itself as the kind of isolation that would respect firewall rules, not that they don't respect them.

People wouldn't make the same mistake in NixOS, despite it doing exactly the same.

load more comments (2 replies)
[–] ohshit604@sh.itjust.works 16 points 3 days ago (6 children)

This post inspired me to try podman, after it pulled all the images it needed my Proxmox VM died, VM won’t boot cause disk is now full. It’s currently 10pm, tonight’s going to suck.

load more comments (6 replies)
[–] grrgyle@slrpnk.net 28 points 4 days ago (1 children)

If I had a nickel for every database I've lost because I let docker broadcast its port on 0.0.0.0 I'd have about 35¢

[–] MangoPenguin@lemmy.blahaj.zone 9 points 4 days ago (8 children)

How though? A database in Docker generally doesn't need any exposed ports, which means no ports open in UFW either.

load more comments (8 replies)
[–] salacious_coaster@infosec.pub 21 points 4 days ago (5 children)

My impression from a recent crash course on Docker is that it got popular because it allows script kiddies to spin up services very fast without knowing how they work.

OWASP was like "you can follow these thirty steps to make Docker secure, or just run Podman instead." https://cheatsheetseries.owasp.org/cheatsheets/Docker_Security_Cheat_Sheet.html

[–] domi@lemmy.secnd.me 50 points 4 days ago

My impression from a recent crash course on Docker is that it got popular because it allows script kiddies to spin up services very fast without knowing how they work.

That's only a side effect. It mainly got popular because it is very easy for developers to ship a single image that just works instead of packaging for various different operating systems with users reporting issues that cannot be reproduced.

[–] null_dot@lemmy.dbzer0.com 32 points 4 days ago

I dont really understand the problem with that?

Everyone is a script kiddy outside of their specific domain.

I may know loads about python but nothing about database management or proxies or Linux. If docker can abstract a lot of the complexities away and present a unified way you configure and manage them, where's the bad?

[–] LordKitsuna@lemmy.world 16 points 4 days ago

That is definitely one of the crowds but there are also people like me that just are sick and tired of dealing with python, node, ruby depends. The install process for services has only continued to become increasingly more convoluted over the years. And then you show me an option where I can literally just slap down a compose.yml and hit "docker compose up - d" and be done? Fuck yeah I'm using that

[–] MangoPenguin@lemmy.blahaj.zone 12 points 4 days ago

No it's popular because it allows people/companies to run things without needing to deal with updates and dependencies manually

load more comments (1 replies)
[–] MangoPenguin@lemmy.blahaj.zone 17 points 4 days ago

This only happens if you essentially tell docker "I want this app to listen on 0.0.0.0:80"

If you don't do that, then it doesn't punch a hole through UFW either.

[–] skuzz@discuss.tchncs.de 9 points 3 days ago (1 children)

For all the raving about podman, it's dumb too. I've seen multiple container networks stupidly route traffic across each other when they shouldn't. Yay services kept running, but it defeats the purpose. Networking should be so hard that it doesn't work unless it is configured correctly.

[–] Diplomjodler3@lemmy.world 18 points 3 days ago (1 children)

Or maybe it should be easy to configure correctly?

[–] reksas@sopuli.xyz 3 points 3 days ago

instructions unclear, now its hard to use and to configure

[–] steventhedev@lemmy.world 17 points 4 days ago

You're forgetting the part where they had an option to disable this fuckery, and then proceeded to move it twice - exposing containers to everyone by default.

I had to clean up compromised services twice because of it.

[–] jbk@discuss.tchncs.de 9 points 3 days ago

rootless podman and sockets ❤️

[–] MnemonicBump@lemmy.dbzer0.com 16 points 4 days ago

This is why I install on bare metal, baby!

[–] iamroot@discuss.tchncs.de 8 points 3 days ago (1 children)

We use Firewalld integration with Docker instead due to issues with UFW. Didn't face any major issues with it.

[–] qaz@lemmy.world 5 points 3 days ago

I also ended up using firewalld and it mostly worked, although I first had to change some zone configs.

[–] MasterNerd@lemmy.zip 12 points 4 days ago (6 children)

I mean if you're hosting anything publicly, you really should have a dedicated firewall

load more comments (6 replies)
[–] stupidcasey@lemmy.world 10 points 4 days ago

On windows (coughing)

[–] jwt@programming.dev 11 points 4 days ago (2 children)

Somehow I think that's on ufw not docker. A firewall shouldn't depend on applications playing by their rules.

[–] qaz@lemmy.world 18 points 4 days ago (3 children)

ufw just manages iptables rules, if docker overrides those it's on them IMO

[–] jwt@programming.dev 10 points 4 days ago (4 children)

Feels weird that an application is allowed to override iptables though. I get that when it's installed with root everything's off the table, but still....

load more comments (4 replies)
load more comments (2 replies)
load more comments (1 replies)
load more comments
view more: next ›