virt-cloud-init

Script for preparing cloud init images for virt-manager

Description

This is a bash script that downloads a cloud init Debian image, resizes it, generates an iso image based on cloud-init.yml config, then runs it using virt-manager. Once created, the VM will also be available in your Virtual Machine Manager GUI.

The script itself is designed to work in the directory where you plan to store iso and images for your VMs. It will create the following directories when all procedures are run:

cloud/
disk/
downloads/
virt-cloud-init.sh
cloud-init.yml

• The cloud/ folder will store all the .iso file that were generated based on the cloud-init.yml file.
• The disk/ folder will store disk images of your VMs.
• The downloads/ folder will store all the downloaded .qcow2 images.

Currently, the script can be customized using argument flags. Other customization will be added in the future.

Before a run, edit the cloud-init.yml file according to your needs. Examples can be found at cloud inits GitHub repo.

Script arguments

To view script's instructions, run:

./virt-cloud-init.sh --help

You will get the following text

virt-cloud-init script v0.5.0
ABOUT
Cloud init image preparation tool for virt and virt-manager

SYNTAX
./virt-cloud-init.sh [download|prepare|create|regenerate-cloud-init|all] [-h] [-n|o|m|s|c|net|img|u|i|b] [ARG]

COMMANDS
download               Download iso
prepare                Prepare image and cloud-init iso
create                 Create VM with cloud-init iso (optionally can run)
regenerate-cloud-init  Cleans VM disk off cloud-init, regenerates the iso
all                    Run All commands above consecutively

OPTIONS
-h --help           Print this Help.
-n --name           Specify VM and image name prefix. Default: default-vm
-o --os             Specify OS variant. Default: debian12
-m --memory         Specify VM memory (in MiB). Default: 2048
-s --storage        Specify VM images size (in K|M|G). Default: 16G
-c --cpus           Specify CPU numbers. Default: 2
-net --network      Specify Network name for VM. Default: default
-img --image-index  Specify a known config listed in images.ini. By default asks dynamically.
-u --url            Specify custom url to an .qcow2 image. Default: https://cloud.debian.org/images/cloud/bookworm/daily/latest/debian-12-genericcloud-amd64-daily.qcow2
-i --interactive    Flag to attaching console upon VM start (also boots the VM).
-b --boot           Flag for booting VM after creation.

Upon every run, you get the following interactive prompt:

0) debian13 debian-13-generic-arm64.qcow2
1) debian12 debian-12-genericcloud-amd64-daily.qcow2
2) debian11 debian-11-generic-amd64.qcow2
3) debian10 debian-10-generic-amd64.qcow2
4) ubuntu23.04 lunar-server-cloudimg-amd64.img
5) ubuntu22.04 jammy-server-cloudimg-amd64.img
6) ubuntu20.04 focal-server-cloudimg-amd64.img
7) ubuntu18.04 bionic-server-cloudimg-amd64.img
8) fedora37 Fedora-Cloud-Base-37-1.7.x86_64.qcow2
9) fedora36 Fedora-Cloud-Base-36-1.5.x86_64.qcow2
[✓] fedora37 Fedora-Cloud-Base-37-1.7.x86_64.qcow2 selected

Note: Ubuntu support is WIP

Examples

Download default Debian 11 image:

./virt-cloud-init.sh download

Change VM image name to "my-vm", resize it to 32GB and generate a cloud image iso with config based on cloud-init.yml:

./virt-cloud-init.sh prepare -n my-vm -m 4096 -s 32

Start VM with name "my-vm" and give 4096MB of memory

ℹ Note about Virtual Machine Manager URI

By default, libvert uses qemu:///session URI, hence, VMs created with virt-install will not appear in your Virtual Machine Manager GUI. To fix this issue, export the following variable:

export LIBVIRT_DEFAULT_URI="qemu:///system"

More info on this issue on StackOverflow

./virt-cloud-init.sh run -n my-vm -m 4096

Once you run initialize you vm in the output console, press ctrl + ] to exit tty.

cd /run/media/mbrav/hd1/iso && ./virt-cloud-init.sh all -m 4096 -c 2 -s 12 -n node1