c · gtk4 · systems

vmmanager

a native gtk4 desktop app for managing qemu/kvm virtual machines and incus/lxd containers — from one window.

c gtk4 libvirt qemu kvm incus lxd virtualization linux gpl-3.0

what it is

think proxmox — but as a compiled c binary on your desktop. a native desktop interface using gtk4, libvirt, and libcurl. one binary that manages both qemu/kvm virtual machines and incus/lxd containers from a single gtk4 interface.

i wrote it in c on purpose. i wanted to talk to libvirt directly as a c library, drive the incus rest api over its unix socket with libcurl, and feel where the real complexity in virtualization management lives — instead of letting a high-level framework hide it from me.

where it stands

documented implementation: a gtk4 app with vm and container lifecycle controls, snapshots, monitoring, and console access. the source and setup requirements are available in the repository.

scope: a desktop management client for an existing virtualization setup. it depends on the relevant host services and libraries.

inspect the source and setup ↗

what it does

→dashboard — real-time cpu, ram, and disk monitoring plus vm/container counts, refreshing every few seconds

→virtual machines — create, start, shut down, pause, resume, reboot, force-stop, and delete kvm vms via libvirt

→containers — full lifecycle for incus/lxd containers via the rest api

→snapshots — create, revert, and delete vm snapshots

→console access — launch a vm viewer or a container shell straight from the app

→activity log, search & filter, keyboard shortcuts, persistent settings

move a virtual machine through its states

each button is the libvirt call vmmanager makes. try one that isn't allowed from the current state and libvirt says no. a simplified model that runs in your browser; no machine is touched.

the legal moves
from	call	to
not defined	`virDomainDefineXML`	shut off
shut off	`virDomainCreate`	running
running	`virDomainSuspend`	paused
paused	`virDomainResume`	running
running	`virDomainShutdown`	shut off (the guest is asked politely)
running or paused	`virDomainDestroy`	shut off (pulled, like the plug)
shut off	`virDomainUndefine`	not defined

architecture

the gui is two gtk4 panels — one for vms, one for containers. underneath, the vm panel speaks to libvirt as a c library, and the container panel speaks the incus rest api through libcurl over a unix socket. those two adapters fan out to qemu/kvm and incus/lxd respectively. that's the whole shape: a thin, honest layer over the tools that already do the heavy lifting.

clanguage

gtk 4gui

v2.0.0version

gpl-3.0license

engineering field notes

the hard part: memory ownership around gtk widgets, parsing api responses, and handling a socket that stops responding.
the tradeoff: c and direct library calls take more care than a higher-level wrapper. they also make the boundaries of the system visible.
what i'd improve next: make connection loss, recovery, and failed operations easier to understand from the interface.

why i wrote a vm manager in c →

built by dharun ashokkumar

Dharun Ashokkumar