Multi-node Kubernetes

Usually multi-node Kubernetes installation are suggested for production and larger trials.

Kubernetes multi-node well-known releases

• Kubespray
  • Documentation: https://github.com/kubernetes-incubator/kubespray
  • Minimum requirements:
    • At least three machines (more info on hardware requirements on the Kubernetes website)

Kubespray demo / lab-trial installation scripts

For simplicity, CORD provides some easy-to-use automated scripts to quickly setup Kubespray on an arbitrary number of target machines in few commands.

This is meant only for lab trials and demo use.

At the end of the procedure, Kubespray should be installed.

Requirements

• Operator machine (1x, either physical or virtual machine)
  • Has Git installed
  • Has Python3 installed (https://www.python.org/downloads/)
  • Has Stable version of Ansible installed (http://docs.ansible.com/ansible/latest/intro_installation.html)
  • Is able to reach the target servers (ssh into them)
• Target machines (at least 3x, either physical or virtual machines)
  • Run Ubuntu 16.04 server
  • Able to communicate together (ping one each other)
  • Have the same user cord configured, that you can use to remotely access them from the operator machine
  • The user cord is sudoer on each machine, and it doesn't need a password to get sudoer privileges

Get the Kubespray installation scripts

On the operator machine

git clone https://gerrit.opencord.org/automation-tools

Inside, you will find a folder called kubespray-installer From now on the guide will assume you're running commands in this folder.

More on the Kubespray installation scripts

The main script (setup.sh) provides an helper with instructions. To see it, run ./setup.sh --help.

The two main functions are:

• Install Kubespray on an arbitrary number of target machines
• Export the k8s configuration file path as environment variable to let the user access a specific deployment

Install Kubespray

In the following example we assume that

• Remote machines have the following IP addresses:

  • 10.90.0.101
  • 10.90.0.102
  • 10.90.0.103

• The deployment/POD has been given the arbitrary name onf

The installation procedure goes through the following steps (right in this order):

• Cleans up any old Kubespray installation folder (may be there from previous installations)
• Clones the official Kubespray installation repository
• Copies the public key of the operator machine, over to each target machine
• Installs required software and configures the target machines as prescribed in the Kubespray guide
• Deploys Kubespray
• Downloads and exports the access configuration outside the Kubespray folder, so it won’t be removed at the next execution of the script (for example while trying to re-deploy the POD, or while deploying a different POD)

To run the installation script, type

./setup.sh -i onf 10.90.0.101 10.90.0.102 10.90.0.103

At the beginning of the installation you'll be asked to insert your password multiple times.

At the end of the procedure, Kubespray should be installed and running on the remote machines.

The configuration file to access the POD will be saved in the subfolder configs/onf.conf.

Want to deploy another POD without affecting your existing deployment?

Runt the following:

./setup.sh -i my_other_deployment 192.168.0.1 192.168.0.2 192.168.0.3

Your onf.conf configuration will be always there, and your new my_other_deployment.conf file as well!

Access the Kubespray deployment

Kubectl and helm (look here for more details) need to be pointed to a specific cluster, before being used. This is done through standard KUBECONFIG files.

The script also helps you to automatically export the path pointing to an existing KUBECONFIG file, previously generated during the installation.

To do that -for example against the onf pod just deployed, simply type

source setup.sh -s onf

At this point, you can start to use kubectl and helm.

Done?

Are you done? You're ready to install kubectl and helm. Instructions here.