Deploys a complete OKD high-availability cluster on a KVM hypervisor using Harmony's KVM module. All infrastructure is defined in Rust — no YAML, no shell scripts, no hand-crafted XML.

What it creates

Resource	Details
Virtual network	`harmonylan` — 192.168.100.0/24, NAT
OPNsense VM	2 vCPU / 4 GiB RAM — gateway + PXE
Control plane ×3	4 vCPU / 16 GiB RAM — `cp0` … `cp2`
Worker ×3	8 vCPU / 32 GiB RAM — `worker0` … `worker2`

Architecture

All VMs share the same harmonylan virtual network. OPNsense sits on both that network and the host bridge, acting as the gateway and PXE server.

 Host network (bridge)
        │
┌───────┴──────────┐
│  OPNsense        │  192.168.100.1
│  gateway + PXE   │
└───────┬──────────┘
        │
        │  harmonylan  (192.168.100.0/24)
        ├─────────────┬──────────────────┬──────────────────┐
        │             │                  │                  │
┌───────┴──┐   ┌──────┴───┐   ┌──────────┴─┐   ┌──────────┴─┐
│ cp0      │   │ cp1      │   │ cp2        │   │ worker0    │
│ .10      │   │ .11      │   │ .12        │   │ .20        │
└──────────┘   └──────────┘   └────────────┘   └──────┬─────┘
                                                       │
                                               ┌───────┴────┐
                                               │ worker1    │
                                               │ .21        │
                                               └───────┬────┘
                                                       │
                                               ┌───────┴────┐
                                               │ worker2    │
                                               │ .22        │
                                               └────────────┘

All nodes PXE boot from the network interface. OPNsense serves the OKD bootstrap images via TFTP/iPXE and handles DHCP for the whole subnet.

Prerequisites

Linux host with KVM/QEMU and libvirt installed
libvirt-dev headers (for building the virt crate)
A default storage pool configured in libvirt
Sufficient disk space (~550 GiB for all VM images)

Running

cargo run --bin kvm_okd_ha_cluster

Set RUST_LOG=info (or debug) to control verbosity.

Configuration

Environment variable	Default	Description
`HARMONY_KVM_URI`	`qemu:///system`	Libvirt connection URI
`HARMONY_KVM_IMAGE_DIR`	harmony data dir	Directory for qcow2 disk images

For a remote KVM host over SSH:

export HARMONY_KVM_URI="qemu+ssh://user@myhost/system"

What happens after `cargo run`

The program defines all resources in libvirt but does not start any VMs. Next steps:

Start OPNsense: virsh start opnsense-harmony
Connect to the OPNsense web UI at https://192.168.100.1
Configure DHCP, TFTP, and the iPXE menu for OKD
Start the control plane and worker nodes — they will PXE boot and begin the OKD installation automatically

Cleanup

for vm in opnsense-harmony cp0-harmony cp1-harmony cp2-harmony \
          worker0-harmony worker1-harmony worker2-harmony; do
    virsh destroy "$vm" 2>/dev/null || true
    virsh undefine "$vm" --remove-all-storage 2>/dev/null || true
done
virsh net-destroy harmonylan 2>/dev/null || true
virsh net-undefine harmonylan 2>/dev/null || true

README.md Unescape Escape

OKD HA Cluster on KVM