virt-init-debian

This project is under development.

A java lib for fully automated creation of qemu/KVM based VMs with unattended installation of Debian.

Features:

• creation of a configurable virtual machine (e.g. memory, disk space, cpus, mac, network, ...)
• unattended installation of debian 12 (bookworm) directly from debian installer, no ISO or vm image needed or downloaded
• automatic installation of ssh public key for created unprivileged user
• configurable shared folders with optional /etc/fstab configuration to be mounted on startup
• serial console configured by default
• no graphics configured in vm as intended for server purposes

Hello world

A very simple configuration based on default values:

GeneralConfig generalConfig = new GeneralConfig.Builder()
        .build();

VmConfig vmConfig = new VmConfig.Builder()
        .build("hello-world");

InstallConfig installConfig = new InstallConfig.Builder()
        .withUserFullName("Joe Dummy")
        .withUserName("jdummy")
        .build("ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAICVYEjfT3BdV4gOOPTeLp2ko9w2Sd5s3tfAs0you7/Wx dummy@machine");

new VirtInitDeb(generalConfig, vmConfig, installConfig).execute();

Build

Simple gradle build as usual:

gradle jar

JDK 17 and gradle 8.5 required

Configuration

Configuration is done by three configuration classes each providing a respective builder. See javadocs for more info.

• General configuration for virt-init-debian: GeneralConfig
• Configuration of the VM to be created: VmConfig
• Configuration of the preseeded Debian installation: InstallConfig

Background

This functionality implements a wrapper around virt-install. The unattended installation of Debian is done by taking advantage of the Debian preseed mechanism. A preseed configuration file is generated an passed to virt-install. Some further basic configuration of the newly created machine is done by a post installation bash script which is injected by preseed.

Shared folders

The shared folder option facilitates the virtiofs feature of qemu/kvm. When at least one shared folder is configured, the vm will be configured for shared memory as well as the virtiofs filesystem is added. If a mountpoint is specified the respective directory is created and also an entry in /etc/fstab is generated. The shared folder will be mounted automatically on startup.

Acknowledgements

This project is heavily inspired by https://github.com/pin/debian-vm-install, which provides a bash script for the same purpose.