InfraSIM Virtual Network

A tool to setup two-layer vswitches and network namespaces.

Setup environment

Install PIP:

sudo apt-get install python-pip

Install openvswitch:

sudo apt-get install openvswitch-switch

Install module dependencies:

sudo pip install -r requirements.txt

Usage

Run in command line

Clear any previous environment by:

sudo python recreator.py delete

Write your config.yml and create the new topology:

sudo python recreator.py create

Leverage ivn library in your python code

Import code repo path to your environment variable:

export PYTHONPATH=$PYTHONPATH:$(pwd)

In your code:

from inv.core import Topology
config_file_path = "/path/to/your/config"
topo = Topology(config_file_path)
topo.create() # Create new topology
topo.delete() # Delete existing topology

Terminology

namespace

This is specially about network namespace. Every namespace is a separate network environment. Which means, you can setup two namespace and run infrasim-compute inside, both vBMC of them are listening on port 623, and they both work.

The namespace in config are interested in two groups of definitions:

• interfaces, interfaces are the route through which inside namespace talk with outside. Interface name should be UNIQUE in our implementation. After infrasim virtual network created, you would see your definition in the file /etc/netns/<namespace>/network/interfaces.

• bridges, similar to interfaces but it is inside namespace so we allow a bridge br0 in namespace A and B at the same time. You can specify bridge_ports to bind bridge to one interface, which make it possibly links outside. Or you don't specify bridge_ports which leaves the bridge for namespace-inside usage.

ovs

Define openvswitch in host environment. It connects physical interfaces, virtual interfaces in namespaces and other openvswitches. Hope you have fun building your own lab!

The openvswitch in config are interested in the ports it manages and attributes of itself:

• ports, ports name should be UNIQUE in the whole virtual network. Ports are the entities to make connections.

• attributes of openvswitch itself will be recorded in /etc/network/interfaces.d/<ovs>, so that to be persist after host environment reset.

connection

Define connection FROM network interfaces TO openvswitch ports. PATCH port between two ports is currently NOT supported.

example

With the config.json in our repo, you would build a virtual network like this:

Be careful ens192 is not necessarily in your environment, choose any physical interface or just remove it in the configuration.

Reference

If you want to do some mannual work on openvswitch and namespace, here's some command you can refer to.

• create openvswitch br-int

  sudo ovs-vsctl add-br br-int

• list openvswitch

  sudo ovs-vsctl show

• create port veth0 on br-int

  sudo ovs-vsctl add-port br-int veth0

• list ports on openvswitch br-int

  sudo ovs-vsctl list-ports br-int

• create namespace node0

  sudo ip netns add node0

• create virtual interface einf0, and connect it to port veth0

  sudo ip link add einf0 type veth peer name veth0

• make einf0 inside namespace node0

  sudo ip link set einf0 netns node0

• execute command inside namespace node0

  sudo ip netns exec node0

• up interface einf0, inside node0

  sudo ip netns exec node0 ip link set dev einf0 up

• get dhcp for einf0, if you have DHCP on this network path

  sudo ip netns exec node0 dhclient einf0