clustvirt - Libvirt cluster manager

Clustered virtualization has gotten to complicated. We have a great system for it built into the Linux kernel, with shared software stacks between whatever base distro you want to use.

Every other option has buy in, and buzzwords. I want something truly simple that can manage virtual machines on multiple hosts, integrating with existing tools, running from one/all of the hosts, a raspberry pi, or as a guest machine on the cluster itself.

The mission: Talk to libvirt hosts, coordinate them, manage them, and let people take their clusters back.

Overall goals:

• HA Cluster resource manager (simpler then existing options, just for libvirt)
  • Share secrets
  • Share VM configs
  • know what VM is running on what cluster host
  • trigger migrations of hosts
  • most simple quorum algorithm possible, ability to run 2 hosts reliably, up to ?? hosts without worry
    • Simplest quorum: If the controller can't reach it, it's down.
• Shared Network management
• Shared storage managment
  • Does not include clustered storage configuration
  • Can use different clustered storage systems (just not configure them directly)
• Reliable backup and snapshotting
  • The tools exist for this, just needs to be exposed
• Install on any libvirt system, as long as the basic requirements are met as far as compatibility is concerned
  • Should be able to have hosts on RedHat, Rocky, Arch, Ubuntu, Debian, whatever without worry
• Cloud-init configuration help to create useful and reusable cloud-init files, that don't need to be used by the system only. It's a standard, use it.

Existing tools and libraries to use

• [https://pkg.go.dev/libvirt.org/go/libvirt] Go Bindings for libvirt
  • Not sure if it can be used without libvirt existing on the system it's running on. Worth a try.

Roadmap

• Create simple daemon that can run on 1 or more hosts that will keep track of things
  • Libvirt daemon
    • Host Capabilities
    • Migration Capabilities
    • Secret management
    • Storage pool management
    • Volume management
    • Guest management
    • Connection management (to other libvirt hosts)
• Create a simple WebUI with HTMX to monitor that stuff
• Add the ability to manage that stuff once we can monitor it, through the WebUI.

Special XMLNS definitions

Domain

• xmlns:clustvirt="https://git.staur.ca/stobbsm/clustvirt"

<metadata>
    <clustvirt:data xmlns:clustvirt="https://git.staur.ca/stobbsm/clustvirt/">
        <clustvirt:created>true</clustvirt:created>
        <clustvirt:managed>true</clustvirt:managed>
        <clustvirt:currentHost>host01</clustvirt:currentHost>
        <clustvirt:origHost>host02</clustvirt:origHost>
        <clustvirt:baseGuest>rocky-9-base</clustvirt:baseGuest>
    </clustvirt:data>
</metadata>

Open Source Projects

The following projects are being used as part of ClustVirt. Only those being used directly are listed, not the dependencies.

Go

Library	Use	License
xdg	XDG paths	MIT
spf13/viper	Configuration	MIT
spf13	Command Pattern CLI	Apache 2.0
go-chart/v2	Chart generation	MIT
libvirt	Communications with Libvirtd	MIT
libvirtxml	Libvirt XML parsing and generation	MIT
templ	HTML Templating Engine	MIT
chi/v5	HTTP Routing	MIT

Node NPM

Library	Use	License
tailwindcss	CSS UI library	MIT
tailwindcss/forms	CSS UI library for forms	MIT