I try docker with a simple webapp :

docker run -d -v $(pwd):/app -p 8080:80 image_name

I have docker listen on 8080:

tcp6 0 0 :::8080 :::*
LISTEN 13304/docker

So I can test my web app through localhost:8080

I use iptables with UFW and I deny incoming except: 80, 443 and 22

But surprisingly, if I do a netcat from the Internet to my machine on port 8080 I can have access to my web app !!

Docker must do something special because if I start socat like this :

socat TCP6-LISTEN:8080 TCP4:www.google.fr:80

I see :

tcp6 0 0 :::8080 :::*
LISTEN 11577/socat

But this time I can't connect from the outside ... UFW do the his job ...


Docker was just added his own iptables rules before UFW rules see https://docs.docker.com/articles/networking/ for details.

to avoid the pb I put


in my /etc/default/docker. so I bind only to localhost and it's not reachable from the outside.


Binding to localhost breaks internal routing for me. I use


to fix this problem.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.