Installation will be done using UPI (User Provisioned Infrastrcuture) approach for SNO (Single Node OKD)

Pre-Requisite Steps

Make sure previous steps is done. If not please refer to the previous article:

at this rate, a master.ign and install-config.yaml should be ready.

Droplet Provisioning

there will be two droplet (VM) used for the cluster installation

1) Watcher VM. basically droplet to execute the openshift-install. This VM will be used to monitor the install progress at the OKD server.
2) OKD Cluster Server. a VM that will be used to deploy the OKD cluster

Watch VM will connect to the OKD Cluster service using public domain name and monitor the installation status/progress. Each of the VM should have different specs

Watcher VM Specs

watcher doesnt require big resources. As long as it can execute openshift-install for creating manifest and ignition from install-config.yaml its enough.

Below are the suggested specs

OS : Fedora Core OS (FCOS)
RAM : 2 Gigs
CPU : 2 vCPU
Ensure that the VM specs has openshift-install binary installed on the $PATH. Otherwise, watching the installation progress of OKD cluster would be impossible.

OKD Cluster VM Specs

Dont provision the second droplet/VM before the watcher VM already in places!. Because the droplet spinoff for the cluster will require the master ignition to be attached.

this is where the OKD cluster will be installed using SNO (Single node OKD) mode. Hence, it require a vertically scaled VM.

Below are the suggested specs

OS : Fedora Core OS (FCOS) with pre-attached master ignition
RAM : 32 Gigs
CPU : 8 vCPU

Watcher VM (a recap)

Component needed

openshift-install and openshift client are installed. Openshift install is used to generate manifest and master ignition while openshift client will be used for monitoring. it has “oc” and “kubectl” tools for watching progress/monitoring progress.

Download binary

Openshift install

curl -L -o openshift-install-linux-4.15.0-0.okd-2024-03-10-010116.tar.gz https://github.com/okd-project/okd/releases/download/4.15.0-0.okd-2024-03-10-010116/openshift-install-linux-4.15.0-0.okd-2024-03-10-010116.tar.gz

Openshift Client

curl -L -o openshift-client-linux-4.15.0-0.okd-2024-03-10-010116.tar.gz https://github.com/okd-project/okd/releases/download/4.15.0-0.okd-2024-03-10-010116/openshift-client-linux-4.15.0-0.okd-2024-03-10-010116.tar.gz

Move openshift-install, oc and kubectl to $PATH and extract it

sudo mv openshift-client-linux-4.15.0-0.okd-2024-03-10-010116.tar.gz /usr/local/bin
sudo mv openshift-install-linux-4.15.0-0.okd-2024-03-10-010116.tar.gz /usr/local/bin

Extract

sudo tar -xvf openshift-client-linux-4.15.0-0.okd-2024-03-10-010116.tar.gz
sudo tar -xvf openshift-install-linux-4.15.0-0.okd-2024-03-10-010116.tar.gz

Validation

execute openshift-install, oc and kubectl from any directories. If no error meaning all those three component has been successfully installed.

Creating FNOS ISO for OKD Single Node OKD (SNO)

Create Fedora Droplet or VM

provision either fedora or ubuntu or basically any linux that can support coreos-installer package. The VM will be used purely to create an ISO / image for OKD SNO.

Digitalocean doesnt support ISO format, it need to be converted into cloud VM format at the end of the steps.

Set OKD Version

version used on this article is :

4.15.0-0.okd-2024-03-10-010116

set host variable

export OKD_VERSION=4.15.0-0.okd-2024-03-10-010116

Set target architecture

architecture used on this article is :

x86_64

set architecture variable

export ARCH=x86_64

Download and Install OKD Client

can get the download url from below path

$ curl -L https://github.com/okd-project/okd/releases/download/$OKD_VERSION/openshift-client-linux-$OKD_VERSION.tar.gz -o oc.tar.gz

or simply refer to following section : Component Needed

Generate FCOS ISO for OKD SNO

FCOS ISO Url

openshift has the information about FCOS ISO. below command will printed out the ISO URL.

export ISO_URL=$(openshift-install coreos print-stream-json | grep location | grep $ARCH | grep iso | cut -d\" -f4)

download the ISO

curl -L $ISO_URL -o fcos-live.iso

Determine machine network

get subnet assigned on Digital ocean droplet

ip a | grep ens3

look for tne ens3 to determine the private network subnet.

2: ens3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 82:8c:ed:88:ce:d8 brd ff:ff:ff:ff:ff:ff
    altname enp0s3
    inet 159.223.64.209/20 brd 159.223.79.255 scope global noprefixroute ens3
       valid_lft forever preferred_lft forever
    inet 10.15.0.5/16 brd 10.15.255.255 scope global noprefixroute ens3
       valid_lft forever preferred_lft forever
    inet6 fe80::808c:edff:fe88:ced8/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever

Convert ISO to qcow2

qemu-img convert -f raw -O qcow2 fcos-live.iso fcos-image.qcow2

Exposing Live OS file to public http (for DO Custom Image)

http need bo exposed to that the OKD server can access the bootstrap ignition files.

install python3 on toolbox(basically an development container) because FCOS doesnt come with python3 by default.

sudo dnf install -y python3

move to the folder that actually has bootstrap ignition

cd /var/home/core/meruyacluster
python3 -m http.server 8080

or run in background:

nohup python3 -m http.server 8080 > http.log 2>&1 &

install-config.yaml

apiVersion: v1
baseDomain: milestoneku.com
compute:
- name: worker
  replicas: 0
  hyperthreading: Enabled
controlPlane:
  name: master
  replicas: 1
  hyperthreading: Enabled
metadata:
  name: sno-cluster
networking:
  clusterNetwork:
  - cidr: 10.132.0.0/14
    hostPrefix: 23
  machineNetwork:
  - cidr: 10.130.0.0/16
  networkType: OVNKubernetes
  serviceNetwork:
  - 172.30.0.0/16
platform:
  none: {}
bootstrapInPlace:
  installationDisk: /dev/disk/by-id/scsi-0DO_Volume_okd-volume
pullSecret: 'your auth'
sshKey: |
  ssh-rsa AAAAB...

Generating ignition file

go to folder where the install-config.yaml present and use openshift-install to generate the OKD installation assets (including the bootstrap ignition for SNO setup)

$ ./openshift-install --dir=. create single-node-ignition-config

creating FCOS Iso with embedded

note: on this article, fedora is used as the host VM (temporary VM for installation)

execute below command to install coreos-installer on fedora pod

$ alias coreos-installer='podman run --privileged --pull always --rm \
    -v /dev:/dev -v /run/udev:/run/udev -v $PWD:/data \
    -w /data quay.io/coreos/coreos-installer:release'

embed the ISO with bootstrap ignition

$ coreos-installer iso ignition embed -fi bootstrap-in-place-for-live-iso.ign fcos-live.iso

Create SNO Droplet

minimum is 16 gigs of ram and 8 CPU

once the droplet is created, execute following checklist before executing the openshift-install to actually install the cluster

1. ensure the domain name is configured

- api.<cluster_name>.<base_domain>
- api-int.<cluster_name>.<base_domain>
- *.apps.<cluster_name>.<base_domain>

on this cases is :

milestoneku.com -> point to the droplet ip (A Name DNS)
api.sno-cluster.milestoneku.com -> point to the droplet ip (A Name DNS)
api-int.sno-cluster.milestoneku.com -> point to the droplet ip (A Name DNS)
*.apps.sno-cluster.milestoneku.com -> point to the droplet ip (A Name DNS)

2. DNS Check

make sure those 4 domain can be accessed. Use ns command to check it.

nslookup milestoneku.com
nslookup api.sno-cluster.milestoneku.com
nslookup api-int.sno-cluster.milestoneku.com
nslookup any.apps.sno-cluster.milestoneku.com

3. wait until the boostraping process on OKD VM is completed

Monitoring openshift cluster Installation

on the host VM (after completing above checklist), install the openshift.

openshift-install --dir=. wait-for install-complete

monitor the logs that displayed on the console

Check openshift status on the OKD server

these two command will be able to tell what happened on the openshift.

journalctl -b -f -u release-image.service -u bootkube.service

sudo journalctl -u bootkube.service --no-pager

Check openshift status on Host server (temporary VM)

check whether the openshift nodes has been up

oc node