Installing single node OpenShift to PowerVM

For current OpenShift release, the openshift-install supports to create the special ignition file for SNO installation. This method can be used for any platform.

Requirements for installing OpenShift on a single node

To do the SNO installation, we need two VMs, one works as bastion and another one as OCP node, the minimum hardware requirements as show as below:

VM	vCPU	Memory	Storage
Bastion	2	8GB	50 GB
SNO	8	16GB	120GB

The bastion is used to setup required services and require to be able to run as root. The SNO node need o have the static IP assigned with internet access.

Bastion setup

The bastion's SELINUX has to be set to permissive mode, otherwise ansible playbook will fail, to do it open file /etc/selinux/config and set SELINUX=permissive.

We will use PXE for SNO installation, that requires the following services to be configured and run:

• DNS -- to define api, api-int and *.apps
• DHCP -- to enable PXE and assign IP to SNO node
• HTTP -- to provide ignition and RHCOS rootfs image
• TFTP -- to enable PXE

we will install dnsmasq to support DNS, DHCP and PXE, httpd for HTTP.

Here are some values used in sample configurations:

• 9.47.87.82 -- SNO node's IP
• 9.47.87.83 -- Bastion's IP
• 9.47.95.254 -- Network route or gateway
• ocp.io -- SNO's domain name
• sno -- SNO's cluster_id

dnsmasq setup

Here is a sample configuration file for /etc/dnsmasq.conf:

#################################
# DNS
##################################
#domain-needed
# don't send bogus requests out on the internets
bogus-priv
# enable IPv6 Route Advertisements
enable-ra
bind-dynamic
no-hosts
#  have your simple hosts expanded to domain
expand-hosts


interface=env32
# set your domain for expand-hosts
domain=sno.ocp.io
local=/sno.ocp.io/
address=/apps.sno.ocp.io/9.47.87.82
server=9.9.9.9

addn-hosts=/etc/dnsmasq.d/addnhosts


##################################
# DHCP
##################################
dhcp-ignore=tag:!known
dhcp-leasefile=/var/lib/dnsmasq/dnsmasq.leases

dhcp-range=9.47.87.82,static

dhcp-option=option:router,9.47.95.254
dhcp-option=option:netmask,255.255.240.0
dhcp-option=option:dns-server,9.47.87.83

dhcp-host=fa:b0:45:27:43:20,sno-82,9.47.87.82,infinite


###############################
# PXE
###############################
enable-tftp
tftp-root=/var/lib/tftpboot
dhcp-boot=boot/grub2/powerpc-ieee1275/core.elf

and /etc/dnsmasq.d/addnhosts file:

9.47.87.82 sno-82 api api-int

PXE setup

To enable PXE for PowerVM, we need to install grub2 with:

grub2-mknetdir --net-directory=/var/lib/tftpboot

Here is the sample /var/lib/tftpboot/boot/grub2/grub.cfg:

default=0
fallback=1
timeout=1

if [ ${net_default_mac} == fa:b0:45:27:43:20 ]; then
default=0
fallback=1
timeout=1
menuentry "CoreOS (BIOS)" {
   echo "Loading kernel"
   linux "/rhcos/kernel" ip=dhcp rd.neednet=1 ignition.platform.id=metal ignition.firstboot coreos.live.rootfs_url=http://9.47.87.83:8000/install/rootfs.img ignition.config.url=http://9.47.87.83:8000/ignition/sno.ign

   echo "Loading initrd"
   initrd  "/rhcos/initramfs.img"
}
fi

Download RHCOS image files from here for PXE:

export RHCOS_URL=https://mirror.openshift.com/pub/openshift-v4/ppc64le/dependencies/rhcos/4.12/latest/
cd /var/lib/tftpboot/rhcos
wget ${RHCOS_URL}/rhcos-live-kernel-ppc64le -o kernel
wget ${RHCOS_URL}/rhcos-live-initramfs.ppc64le.img -o initramfs.img
cd /var//var/www/html/install/
wget ${RHCOS_URL}/rhcos-live-rootfs.ppc64le.img -o rootfs.img

Create the ignition file

To create the ignition file for SNO, we need to create the install-config.yaml file, first we need to create the work directory to hold the file:

mkdir -p ~/sno-work
cd ~/sno-work

Using following sample file to create the required install-config.yaml:

apiVersion: v1
baseDomain: <domain>
compute:
- name: worker
  replicas: 0 
controlPlane:
  name: master
  replicas: 1 
metadata:
  name: <cluster_id>
networking: 
  clusterNetwork:
  - cidr: 10.128.0.0/14
    hostPrefix: 23
  machineNetwork:
  - cidr: 9.47.80.0/20 
  networkType: OVNKubernetes
  serviceNetwork:
  - 172.30.0.0/16
platform:
  none: {}
bootstrapInPlace:
  installationDisk: <device> 
pullSecret: '<pull_secret>' 
sshKey: |
  <ssh_key> 

Note:

• <domain>: Set the domain for your cluster, like ocp.io.
• <cluster_id>: Set the cluster_id for your cluster, like sno.
• <ssh_key>: Add the public SSH key from the administration host so that you can log in to the cluster after installation.
• <pull_secret>: Copy the pull secret from the Red Hat OpenShift Cluster Manager and add the contents to this configuration setting.
• <device>: Provide the device name where the RHCOS will be installed, like /dev/sda or /dev/disk/by-id/scsi-36005076d0281005ef000000000026803.

Download the openshift-install:

wget wget https://mirror.openshift.com/pub/openshift-v4/ppc64le/clients/ocp/4.12.0/openshift-install-linux-4.12.0.tar.gz
tar xzvf openshift-install-linux-4.12.0.tar.gz

Create the ignition file and copy it to http directory:

./openshift-install --dir=~/sno-work create create single-node-ignition-config
cp ~/sno-work/single-node-ignition-config.ign /var/www/html/ignition/sno.ign
restorecon -vR /var/www/html || true

Now bastion has all required files and configurations to install SNO.

SNO installation

There two steps for SNO installation, first the SNO LPAR need to boot up with PXE, then monitor the installation progress.

Network boot

To boot powerVM with netboot, there are two ways to do it: using SMS interactively to select bootp or using lpar_netboot command on HMC. Reference to HMC doc for how to using SMS.

Here is the lpar_netboot command:

lpar_netboot -i -D -f -t ent -m <sno_mac> -s auto -d auto -S <server_ip> -C <sno_ip> -G <gateway> <lpar_name> default_profile <cec_name>

Note:

• <sno_mac>: MAC address of SNO
• <sno_ip>: IP address of SNO
• <server_ip>: IP address of bastion (PXE server)
• : Network's gateway IP
• <lpar_name>: SNO lpar name in HMC
• <cec_name>: System name where the sno_lpar resident at

Monitoring the progress

After the SNO lpar boot up with PXE, we can use openshift-install to monitor the progress of installation.

# first need to wait for bootstrap complete
./openshift-install wait-for bootstrap-complete
# after it return successfully, using following cmd to wait for completed
./openshift-install wait-for install-complete

Also we can use oc to check installation status:

export KUBECONFIG=~/sno-work/auth/kubeconfig
# check SNO node status
oc get nodes
# check installation status
oc get clusterversion
# check cluster operators
oc get co
# check pod status
oc get pod -A