bcvk - bootc virtualization kit

This project helps launch ephemeral VMs from bootc containers, and also create disk images that can be imported into other virtualization frameworks.

Installation

See docs/src/installation.md.

Quick Start

Running a bootc container as ephemeral VM

This doesn't require any privileges, it's just a wrapper for podman. It does require a virt stack (qemu, virtiofsd) in the host environment.

bcvk ephemeral run -d --rm -K --name mytestvm quay.io/fedora/fedora-bootc:42
bcvk ephemeral ssh mytestvm

Or to fully streamline the above and have the VM automatically terminate when you exit the SSH client:

bcvk ephemeral run-ssh quay.io/fedora/fedora-bootc:42

Everything with bcvk ephemeral creates a podman container that reuses the host virtualization stack, making it simple to test bootc containers without requiring root privileges or dedicated VM infrastructure.

Creating a persistent bootable disk image from a container image

# Install bootc image to disk
bcvk to-disk quay.io/centos-bootc/centos-bootc:stream10 /path/to/disk.img

Image management

There's a convenient helper function which filters by all container images with the containers.bootc=1 label: bcvk images list

libvirt integration

The libvirt commands provide comprehensive integration with libvirt infrastructure for managing bootc containers as persistent VMs.

Starting a bootc container as a libvirt VM

# Basic libvirt VM creation with default settings (2GB RAM, 2 CPUs, 20GB disk)
bcvk libvirt run quay.io/centos-bootc/centos-bootc:stream10

# Note requirement for --filesystem with the generic Fedora bootc base images
bcvk libvirt run --filesystem btrfs quay.io/fedora/fedora-bootc:43

# Custom VM with specific resources and name
bcvk libvirt run --name example-vm --memory 4096 --cpus 4 --disk-size 50G quay.io/centos-bootc/centos-bootc:stream10

# This example forwards a port and bind mounts content from the host
bcvk libvirt run --name web-server --port 8080:80 --volume /host/data:/mnt/data localhost/myimage

# Bind mount the host container storage for faster updates
bcvk libvirt run --update-from-host --name devvm localhost/myimage

Using and managing libvirt VMs

After initializing a VM a common next step is bcvk lbivirt ssh <vm name>. bcvk defaults to injecting SSH keys via systemd credentials. The private key is specific to the VM and is stored in the domain metadata.

Other operations:

# List all bootc-related libvirt domains
bcvk libvirt list

# Stop a running VM
bcvk libvirt stop my-fedora-vm

# Start a stopped VM
bcvk libvirt start my-fedora-vm

# Get detailed information about a VM
bcvk libvirt inspect my-fedora-vm

# Remove a VM and its resources
bcvk libvirt rm -f my-fedora-vm

Other operations

The bcvk libvirt run command wraps bcvk to-disk which in turns wraps bootc install to-disk in an ephemeral VM. In some cases, you may want to create a disk image directly.

# Generate a disk image in qcow2 format.
bcvk to-disk --format=qcow2 localhost/my-container-image output-disk.qcow2

Note that at the current time, this project is not scoped to output other virtualization formats. The bootc image builder is one project that offers those.

Goals

This project aims to implement part of https://gitlab.com/fedora/bootc/tracker/-/issues/2.

Basically it will be "bootc virtualization kit", and help users run bootable containers as virtual machines.

Related projects and content:

• https://github.com/coreos/coreos-assembler/
• https://github.com/ublue-os/bluefin-lts/blob/main/Justfile

Development

See docs/HACKING.md.