lxc-network

A network of LXC containers, managed through libvirt

Dependencies

This script will most probably break on any other system than Linux, and will definitely break on anything non-UNIX.

It relies on libvirt, overlayfs and sudo (to gain the required privileges to use overlayfs).

Setup

It is recommended to set up lxc-network within a virtualenv:

virtualenv -p python3 venv
source venv/bin/activate
pip install -r requirements.txt

Furthermore, you are expected to set up a system root tree within the directory of your choice, and put its path in lxc_net/settings.py. This can be done eg. in ArchLinux with

pacstrap [your_root_directory] base

or the equivalent debootstrap command on Debian.

This system is expected to use systemd, and to have enabled systemd-networkd to setup its IP addresses.

Usage

You can spawn a network using

./spawn_network.py topology_description.yml

where topology_description.yml is a valid topology description file (see below).

When the network is spawned, you will get a (very basic) prompt. The available commands are:

• help: display a list of available commands;
• exit: cleanup the network and quit the program;
• dom:
  • dom down: keep the networks up, but cleanup the containers. Useful to reset the containers or update binaries and settings.
  • dom up: spawn the containers, if they were cleaned up beforehand.
  • dom restart: equivalent to dom down ; dom up.

Topology description file

A topology is described in a YAML file looking like this:

---
links:
  - domains: ['a', 'b']
    enable_v4: false
  - domains: ['b', 'c']
domains:
  b:
    enable_v4: false
    root_path: /path/to/root

The links element is mandatory, each link containing a mandatory domains attribute, the list of domains (containers) connected to it. A domain is described by an arbitrary name. Domains will be spawned (and indexed) in alphabetical order.

The valid options for links are:

• enable_v4: boolean, specifies whether the NICs connected to this link have an IPv4 address.

A domains root element is optional, and may be used to specify domain-specific options.

The valid options for domains are:

• enable_v4: boolean, specifies whether the domain has IPv4 addresses on its NICs.
• root_path: an optional path to a directory containing the root to use for this domain