by Devin Yang
(This article was automatically translated.)

Published - 2 years ago ( Updated - 2 years ago )

First of all, in the Linux environment, Docker uses iptables rules to provide network isolation.
However, in the environment of Docker swarm mode, we cannot identify the connection port under 127.0.0.1 of the host.
At this time, we can customize the rules through the DOCKER-USER chain in iptables.

Docker installs two custom iptables chains named DOCKER-USER and DOCKER, which ensures that incoming packets are always inspected first by these two chains.

All iptables rules for Docker are added to the DOCKER chain. Do not manipulate this chain manually.

If you need to add rules that load before Docker rules,

use the DOCKER-USER chain. These rules are enabled before any rules created automatically by Docker.

For example, my nginx has opened port 8081, which represents the input host's ip, adding port 8081 can access the host.

cyh3692mbacl   dlaravel_web          replicated   4/4        nginx:latest      *:8081->80/tcp

But in fact, I prefer to access the host through HAProyx, instead of opening the host's ip and port 8081 to access it. The solution is to adjust iptables.

We can use the following command to view the previous rules

iptables -nL DOCKER-USER
RETURN     all  --  0.0.0.0/0            0.0.0.0/0

Basically it is completely open, we can write a bash as follows, please note that this is just an example, please adjust it according to your own needs.
This example includes different network segments or specific IP and network card.

#!/bin/bash
iptables -F DOCKER-USER
#全檔只能用本機的ip存取
iptables -I DOCKER-USER -p tcp -m multiport --dports 8025,8084,30001,30020 -j DROP
#鎖區網在可以連
iptables -I DOCKER-USER -i eno1 ! -s 10.0.0.26 -p tcp -m multiport --dports 8080,8081 -j DROP
iptables -I DOCKER-USER -i eno2 ! -s 192.168.88.0/24 -p tcp -m multiport --dports 3306,2222,1024 -j DROP
iptables -A DOCKER-USER -j RETURN
#列出規則
iptables -nL DOCKER-USER

At the beginning I cleared all rules first

iptables -F DOCKER-USER

I won't say much about the rest, I believe everyone can guess it.

 

 

Tags: docker

Devin Yang

Feel free to ask me, if you don't get it.:)

No Comment

Post your comment

Login is required to leave comments

Similar Stories


docker

Storage and retrieval of Docker image

How to archive the docker image into a tar file and load back the docker image. We can use docker save and docker load.

docker

About Docker's Logging Driver

Docker has a lot of built-in log mechanisms to help us obtain service information executed in the container. These mechanisms (mechanisms) we usually call logging drivers.

openai,flax,docker

Use the container to run OpenAI's official teaching Python (Flax)

If you log in to the openai website, you can see the official teaching instructions herehttps://beta.openai.com/docs/quickstart/build-your-applicationAPI的KEY的申請, there is a button at the bottom of this page + Create new secret key This article teaches you to use Docker to run the official OpenAI execution environment.