persica cluster

This is a cluster of three identical nodes, named persica1/2/3

• Alma Linux 9.1 x64
• Dell Optiplex 9020 Micro
  • Intel Core i5-4590T @ 2.00 GHz
  • 16gb DDR3-1600
  • 128gb SSD

k8s notes

• Make a simple 3-node cluster
• Single-node control plane will run externally, on illustrious

• Use kubeadm to build the cluster: https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/install-kubeadm/

• Selected containerd as the container runtime
• Will use Flannel as the networking plugin
• Allocated IPs:
  • persica1 / 192.168.1.31
  • persica2 / 192.168.1.32
  • persica3 / 192.168.1.33
• Ingress: undecided so far
• Cgroup driver: let's use systemd
• k8s version: whatever is latest right now (2023-04-04)

Build notes

• Full UEFI mode
• PXE boot for kickstart install
• tftpd-hpa running on illustrious

  • Upstream repo mirror: https://repo.almalinux.org/almalinux/9/BaseOS/x86_64/os/EFI/BOOT/

• kickstart file served from /data/www/illustrious/ks: https://illustrious.thighhighs.top/ks/persica1.ks.cfg

• KS references:

  • Reference manual: https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/9/html/performing_an_advanced_rhel_9_installation/kickstart-commands-and-options-reference_installing-rhel-as-an-experienced-user#keyboard-required_kickstart-commands-for-system-configuration

  • Generator tool: https://access.redhat.com/labs/kickstartconfig/

• k8s doesn't play well with swap so we need to disable it. Provision a minimal swap volume of 1gb, then disable it later

This was useful for figuring out the TFTP stuff for the first time. Paths are hardcoded into the grubx64.efi binary, meaning HDD and PXE versions aren't the same. Make sure you put all the grub stuff in a grub/ directory. Check the $prefix to see where it's searching: https://askubuntu.com/questions/1183487/grub2-efi-boot-via-pxe-load-config-file-automatically

I should ansible'ise everything. Can I start with this?

AlmaLinux 9 - AppStream                                                                                                                                                                          3.0 MB/s | 3.1 kB     00:00
Importing GPG key 0xB86B3716:
 Userid     : "AlmaLinux OS 9 <packager@almalinux.org>"
 Fingerprint: BF18 AC28 7617 8908 D6E7 1267 D36C B86C B86B 3716
 From       : /etc/pki/rpm-gpg/RPM-GPG-KEY-AlmaLinux-9
Is this ok [y/N]: y
Key imported successfully