Provision a Kubernetes Cluster on Citrix XenServer

You can now provision a Kubernetes cluster on a Citrix Xenserver using this tool. You can also specify the required CNI, node count and Kubernetes version.
This is an Ansible based tool that used KubeADM to bring up the Kubernetes Cluster.

This tool would create the Nodes in the XenServer for you and then install Kubernetes on them based on the parameters which you specify.

Pre-requisites:

1. Required Packages

apt install python-pip
pip install ansible
pip install XenAPI
apt install sshpass
export ANSIBLE_HOST_KEY_CHECKING=False

2. VM Template needs to be created. This is a one time process. This step can be skipped, if you choose not to provision nodes.

A detailed guide on how to create a VM export is given here

Note Support for installing nodes from pre-built VM templates is work-in-progress.

Let the tool know your requirements for creating the Kubernetes cluster

Clone this repository and modify the vars/config.yml file according to your needs

https://github.com/christus02/kubexen.git
cd kubexen

Edit the vars/config.yml file. Below are some of the parameters to be changed.

Specify the Xen Server details in the below section

xenserver:
  hostname: <IP/Hostname of the XenServer>
  username: <Username of the XenServer>
  password: <Password of the XenServer>

Provide the Free IPs in the XenServer management range. The Kubernetes nodes would be assigned these IPs after bring up.

The IPs should be specified as CIDR.

The First IP would be assigned to the Master Node

ip_config:
  ip:
  # Specify the IPs to be assigned for the nodes as CIDR (IP/PREFIX)
  - 10.0.0.11/24 # The first IP would be considered as Master
  - 10.0.0.12/24 # Worker Node 1
  - 10.0.0.13/24 # Worker Node 2
  gateway: 10.0.0.1

Choosing CNI:

You can provide the CNI to be installed in the below section.

cluster_configs:
  # Possible CNI list:
  # TODO
  cni: 'flannel'

Choosing the Kubernetes Version:

You can provide the Kubernetes Version to be installed in the below section.

cluster_configs:
  # Specify the Kubernetes version you wish to install
  version: '1.18.0'

Save the vars/config.yml file and exit.

Create the Kubernetes Cluster

Now that you have updated the vars/config.yml file, run the Ansible playbook to provision VMs and create Kubernetes cluster

ansible-playbook kubexen.yml

Let the playbook run and in few more minutes your cluster would be UP and RUNNING.

Logging in to the Kubernetes Master

Login to the Master IP provided in the vars/config.yml with the vm.template_username and vm.template_password specified in the vars/config.yml file

After logging in, you can execute the usual kubectl commands.

Your Kubernetes cluster is now UP and READY.

Delete a Kubernetes Cluster

Make sure the vars/config.yml is not changed and execute the below command to delete the created Kubernetes cluster

ansible-playbook kubexen.yml -t delete

The Kubernetes cluster can also be deleted by manually deleting the VMs from the XenCenter.

DNS Resolution

All the nodes in the Kubernetes cluster can reach each other using the hostnames. This is made possible as the hostnames are configured as xip.io domain names.

Work-In-Progress:

1. Support all possible CNI
2. Option to bring up just Kubernetes without provisioning VMs
3. Make this tool Docker Ready
4. Support for importing a VM template from URL