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How are the iptables rules loaded in Docker?
All of Docker’s iptables rules are added to the DOCKER chain. Do not manipulate this table manually. If you need to add rules which load before Docker’s rules, add them to the DOCKER-USER chain. These rules are loaded before any rules Docker creates automatically.
How to manage iptables rules with UFW and Docker?
Now you have to tell the firewall that the rules defined by UFW must be executed before those of Docker. Let’s add these lines to the /etc/ufw/after.rules file. Note that the $INTERFACE variable must be replaced with the name of the primary host interface used by Docker (such as eth0 or eno1).
What do the firewall rules do in Docker?
When using Docker, it has added a whole bunch of firewall rules by default. These rules allow you to intelligently route the host machine’s ports to the right containers, but also to allow exchanges between several networks (in a Swarm, for example). It is, however, complicated to set up our own rules when Docker issues its own.
What is the ipset name for a docker container?
The ipset name defining the IPs allowed to access your Docker containers. Configuring iptables rules for Docker containers is a bit tricky. At first, you would think that “classic” firewall rules should do the trick.
How to limit external access to a docker container?
To allow only a specific IP or network to access the containers, insert a negated rule at the top of the DOCKER filter chain. For example, to restrict external access such that only source IP 8.8.8.8 can access the containers, the following rule could be added: iptables -I DOCKER -i ext_if ! -s 8.8.8.8 -j DROP
Can a docker container connect to any IP address?
By default, all external source IPs are allowed to connect to the Docker host. To allow only a specific IP or network to access the containers, insert a negated rule at the top of the DOCKER-USER filter chain. For example, the following rule restricts external access from all IP addresses except 192.168.1.1:
How to restrict in and outbound traffic in Docker?
So if you live in the 192.168.0.0/24 network and you have something running on 192.168.0.1 (maybe your wifi router), you should see a response when executing: The attentive reader might have noticed that the entrypoint.sh checks if the environment variable ALLOWED_CIDR is set and takes the CIDR notated network instead of the fallback:
https://www.youtube.com/watch?v=ks5P5N3v2l8