lxc-routednet

README

LXC Routed Network Hook

This tool is designed to be used as an LXC network hook script to emulate OpenVZ style venet networking. It uses a veth pair between the host and the container, and then uses proxy ARP and NDP on the host to advertise the container's IP addresses to the network.

It uses an embedded gratuitous ARP and NDP advertisement system so no external dependencies are needed.

Each of the container's IPs are compared against the IP/Subnet of the host interfaces, and if a container's IP is within one of the host's network interface subnets, proxy ARP/NDP is configured on that interface.

If no matching host interface can be found, then no proxy ARP/NDP is configured, however a static route is still added to the container, in case the IP is routed to the host.

Example Usage:

/var/lib/lxc/test/config

# Network configuration
lxc.net.0.type = veth
lxc.net.0.flags = up
lxc.net.0.name = eth0
lxc.net.0.ipv4.address = 192.168.31.3/32
lxc.net.0.ipv4.gateway = 169.254.0.1
lxc.net.0.ipv6.address = 2a00:1098:0:xx:xxxx::3/128
lxc.net.0.ipv6.gateway = fe80::1
lxc.net.0.script.up = /usr/libexec/lxc/lxc-routednet
lxc.net.0.script.down = /usr/libexec/lxc/lxc-routednet

Note:

The IP addresses defined must be a /32 (IPv4) or /128 (IPv6) respectively. The gateway IPs have been selected on purpose as "unused" addresses that do not exist in the external network. They are just used as a way to get packets from the container to the host system.

Installation

go get -u github.com/tomponline/lxc-routednet
cp `go env GOPATH`/bin/lxc-routednet /usr/libexec/lxc/

Documentation

Overview

lxc-routednet hook that provides routed network connectivity for LXC containers.