VTN Setup

The ONOS VTN app provides virtual networking between VMs on an OpenStack cluster. Prior to installing the base-openstack chart that installs and configures VTN, make sure that the following requirements are satisfied.

SSH access to hosts

VTN requires the ability to SSH to each compute node using an account with passwordless sudo capability. Before installing this chart, first create an SSH keypair and copy it to the authorized_keys files of all nodes in the cluster:

Generate a keypair:

ssh-keygen -t rsa

Copy the public key for user ubuntu to node1.opencord.org (example):

ssh-copy-id [email protected]

Copy the private key so that the base-openstack chart can publish it as a secret:

cp ~/.ssh/id_rsa xos-profiles/base-openstack/files/node_key

Fabric interface

The VTN app requires a fabric interface on the compute nodes. VTN will not successfully initialize if this interface is not present. By default the name of this interface is expected to be fabric.

Interface not named 'fabric'

If you have a fabric interface on the compute node but it is not named fabric, create a bridge named fabric and add the interface to it. Assuming the fabric interface is named eth2:

sudo brctl addbr fabric
sudo brctl addif fabric eth2
sudo ifconfig fabric up
sudo ifconfig eth2 up

To make this configuration persistent, add the following to /etc/network/interfaces:

auto fabric
iface fabric inet manual
  bridge_ports eth2

Dummy interface

If there is not an actual fabric interface on the compute node, create a dummy interface as follows:

sudo modprobe dummy
sudo ip link set name fabric dev dummy0
sudo ifconfig fabric up

DNS setup

In order to be added to the VTN configuration, each compute node must be resolvable in DNS. If a server's hostname is not resolvable, it can be added to the local kube-dns server (substitute HOSTNAME with the output of the hostname command, and HOST-IP-ADDRESS with the node's primary IP address):

cat <<EOF > /tmp/HOSTNAME-dns.yaml
kind: Service
apiVersion: v1
metadata:
  name: HOSTNAME
  namespace: default
spec:
  type: ExternalName
  externalName: HOST-IP-ADDRESS
EOF
kubectl create -f /tmp/HOSTNAME-dns.yaml