Setting up network bonding on specific interfaces during the ignition process

Overview

This guide explains how to bond specific NICs during the initial OpenShift installation with OVS and supplies the Ignition and scripts to achieve this.

Important

This guide describes the customisations needed for installation when using a PXE server.

Prerequisites

• Fcct software to be able to convert fcc to ign files.
• PXE server with ability to set kernel arguments.
• Web accessible location (HTTP only) to upload the custome ign files.

Usage

1. Adding parameters to PXE server

Key	Type	Value	Exmaple	Discription
ignition.config.url	String	http://{location reachable to PXE and remote VM in order to get the ignition file}/file.ign custom-config	ignition.config.url=http://my.web.server.redhat.com/file.ign custom-config	This parameter is used to allow the server to load an extra ignition file which captures the MAC addresses and saves them into a file for later use in machine config.
macAddressList	String	List of MAC address should be set per host In the following order: 1. Primary NIC 2. Secondary NIC 3. All the rest (optional)	00:01:02:03:04:05,06:07:08:09:10:11 ...	This will be the list of MAC addresses which exist on the host and will be grabbed by the ignition file.

2. Prepare the files

• Create the ign file from the custom-config.fcc:

fcct custom-config.fcc > file.ign

• Upload file.ign to a shared location which the OpenShift nodes can access.

• Base64 encode the setup-ovs.sh file and paste the content into each MCO file into "base64_script_content" section.

  TIP: To update the content you can use:

export base64_script_content=$(cat setup-ovs.sh|base64 -w 0) && envsubst <  mco_ovs_workers.yml.tmpl > mco_ovs_workers.yml && envsubst < mco_ovs_supervisor.yml.tmpl > mco_ovs_supervisor.yml

• MCO files are MachineConfig, which you can apply manually once the cluster is up or add it to the installation automation/pipeline.

3. Run the installation

• Follow the guide to install a bare-metal cluster in the OpenShift production documentation.

Notes

• Changing network configuration is done with the setup-ovs.sh file.

• In order to change the bond type to something other than balance-slb (for example active-backup) ,open the setup-ovs.sh file and search for the “#make bond” section. Change “ovs-port.bond-mode” to the desired type and make sure that all other related settings are aligned.

• MachineConfig file is a “Day 2” tool that allows to configure or run scripts on a machine with an installed OS (post-installation).

Additional Documentation

• Redhat CoreOS (RHCORS) features including ignition and machineConfig explanation

• Understanding Machine Config