Centos iptables fails with docker rules - docker

Question

I have installed a docker service:
docker run --rm --name some-nginx -d -p 8080:80 nginx:stable-alpine
Then I have added iptable rule for it:
PORT=8080
/sbin/iptables -A OUTPUT -p tcp --dport $PORT -m state --state NEW,ESTABLISHED -j ACCEPT
/sbin/iptables -A INPUT -p tcp --sport $PORT -m state --state ESTABLISHED -j ACCEPT
When I try to check if port is open it says it is open:
$netstat -anp | grep 8080
tcp6 0 0 :::8080 :::* LISTEN 11211/docker-proxy
When I try to investigete more it seems still open:
iptables-save | grep 8080
-A DOCKER ! -i docker0 -p tcp -m tcp --dport 8080 -j DNAT --to-destination 172.17.0.3:80
-A INPUT -p tcp -m tcp --sport 8080 -m state --state ESTABLISHED -j ACCEPT
-A OUTPUT -p tcp -m tcp --dport 8080 -m state --state NEW,ESTABLISHED -j ACCEPT
I see docker added some rules but my rules are present.
The problem is I cant connect to nginx at given port!
telnet XX.XX.XX.XX 8080
Trying XX.XX.XX.XX...
telnet: Unable to connect to remote host: Connection timed out
When I turn off iptables it works even with browser giving nginx start page.
How to enable iptables or docker to work with given port?

Answer 1

i have some pages you can read.:
https://fralef.me/docker-and-iptables.html
https://riptutorial.com/docker/topic/9201/iptables-with-docker
I have also a linux, try this here:
iptables -A INPUT -p tcp -m tcp --dport xxx -j ACCEPT
iptables -A OUTPUT -p tcp --sport xxx -m state --state ESTABLISHED -j ACCEPT
or
iptables -A OUTPUT -o eth0 -p tcp --dport xxx -m state --state NEW,ESTABLISHED -j ACCEPT
iptables -A INPUT -i eth0 -p tcp --sport xx -m state --state ESTABLISHED -j ACCEPT
Let me know if it helps.