The xci/installer/kubespray/files/k8s-cluster.yml is obtained from kubespray.
You can change the parameters according to your needs.
When  starting the deploy, it will be copied to the right directory and will be used by kubespray

For example:
  kube_network_plugin: calico
  docker_storage_options: -s overlay2
  kube_service_addresses: 10.233.0.0/18

Requirements:
  1. Performance of hosts
      The performance settings are not required officially. I recommend the following:
       - VM_CPU=6
       - VM_DISK=80GB
       - VM_MEMORY_SIZE=16GB

  2. Distributions
       - Ubuntu 16.04

  3. Packages:
       - Ansible v2.4 (or newer) and python-netaddr is installed on the machine that will run Ansible commands
       - Jinja 2.9 (or newer) is required to run the Ansible Playbooks

  4. Others:
       - The target servers must have access to the Internet in order to pull docker images.
       - The target servers are configured to allow IPv4 forwarding.
       - Your ssh key must be copied to all the servers part of your inventory.
       - The firewalls are not managed, you'll need to implement your own rules the way you used to. In order to avoid any issue during the deployment you should disable your firewall.

Flavors:
  1. aio: Single host which acts as the deployment host, master and node.
  2. mini: One deployment host, 1 master host and 1 node host.
  3. noha: One deployment host, 1 master host and 2 node hosts.
  4. ha: One deployment host, 3 master hosts and 2 node hosts.

Components Installed:
  1. etcd
  2. network plugins:(one of following, which you can choose. Default is calico)
       - calico
       - flannel
       - contive
       - weave
  3. kubernetes
  4. docker

How to use:

Clone the OPNFV Releng repository

    git clone https://gerrit.opnfv.org/gerrit/releng-xci.git

Change into the directory where the sandbox script is located

    cd releng-xci/xci

Set the variable to run kubespray

    export XCI_INSTALLER=kubespray
    export DEPLOY_SCENARIO=k8-nosdn-nofeature
    export XCI_FLAVOR=mini

Execute sandbox script

    ./xci-deploy.sh