This repository contains the Golang source code for the kathara/katharanp Docker Network Plugin.

This plugin creates pure L2 LANs using bridges and veths.

To avoid assigning any IP subnet you MUST use --ipam-driver=null when creating networks with kathara/katharanp plugin. Otherwise, the veth endpoint inside the container will always receive an IP address from the default pool.

The plugin is compiled and released for both amd64 and arm64 architectures. The tag of the plugin identifies the architecture. For backward compatibility, the latest tag is a retag of the amd64 version.

To build the plugin, type on terminal:

$ make all_<arch>

Where <arch> can be: amd64 or arm64.

The build process leverages on Docker, so you don't need any dependencies installed in your machine.

It is possible to leverage on katharanp as a standalone Docker Network Plugin, in order to create pure L2 networks.

Note that using nftables as the iptables backend requires a xtables.lock file in order to work properly. Hence the same host lock should be shared (and hence, mounted) with the network plugin container.

So, install the plugin passing the path of your xtables.lock file to the plugin configuration, with the following command:

docker plugin install kathara/katharanp:amd64 xtables_lock.source="/var/run/xtables.lock"
# or
docker plugin install kathara/katharanp:arm64 xtables_lock.source="/var/run/xtables.lock"

At this point, you can create a network using the standard Docker command:

docker network create --driver=kathara/katharanp:amd64 --ipam-driver=null l2net
# or
docker network create --driver=kathara/katharanp:arm64 --ipam-driver=null l2net

If the Docker daemon does not start properly while using the plugin with xtables.lock mount (e.g., "No such file or directory" error), follow these steps.

Create a dummy xtables.lock file:

touch /var/run/xtables.lock

Start the Docker daemon and immediately disable and remove the katharanp plugin:

docker plugin remove -f kathara/katharanp:amd64
# or
docker plugin remove -f kathara/katharanp:arm64

Install it without mounting the xtables.lock file:

docker plugin install kathara/katharanp:amd64
# or
docker plugin install kathara/katharanp:arm64