Cloud Images in EVE-NG

EVE-NG has documentation on how set up Linux nodes, but provides prepared images. This is helpful, but the latest Ubuntu image is 20.04.2 and we don’t know the origins of these images.

Fortunately, it’s easy to get Ubuntu and Debian cloud images working in EVE-NG

Create Custom Template

We will need to create a custom template as we will want some options that aren’t specified in the Linux one

# linux-cloud.yml
---
type: qemu
description: Linux Cloud Image
name: Linux Cloud Image
cpulimit: 1
icon: Server.png
cpu: 1
ram: 1024
ethernet: 1
console: telnet
shutdown: 1
qemu_arch: x86_64
qemu_version: 2.12.0
qemu_nic: virtio-net-pci
qemu_options: -machine type=pc,accel=kvm -nographic -usbdevice tablet -boot order=cd -cpu host -serial mon:stdio
...

After saving this, we can copy it to the AMD & Intel directories where templates are kept

cp linux-cloud.yml /opt/unetlab/html/templates/amd
cp linux-cloud.yml /opt/unetlab/html/templates/intel

Finally, we just need to register the custom template so EVE-NG knows it exists

# /opt/unetlab/html/includes/custom_templates.yml
---
custom_templates:
  - name: linux-cloud
    listname: Linux Cloud
...

Create Image Folder(s)

You will need to create a folder on your EVE-NG machine for each cloud image version you want to use.

mkdir /opt/unetlab/addons/qemu/linux-cloud-ubuntu-24.04
mkdir /opt/unetlab/addons/qemu/linux-cloud-debian-12

Download Image(s)

Both Ubuntu and Debian provide cloud images for download, the location for these can be found below

• Ubuntu Cloud Images
  • eg. noble-server-cloudimg-amd64.img
• Debian Cloud Images
  • eg. debian-12-genericcloud-amd64.qcow2

We will download these to our EVE-NG server into the image folder created above

Ubuntu:

cd /opt/unetlab/addons/qemu/linux-cloud-ubuntu-24.04
wget https://cloud-images.ubuntu.com/noble/current/noble-server-cloudimg-amd64.img \
    -O virtioa.qcow2

Debian:

cd /opt/unetlab/addons/qemu/linux-cloud-debian-12
wget https://cloud.debian.org/images/cloud/bookworm/latest/debian-12-genericcloud-amd64.qcow2 \
    -O virtioa.qcow2

Optional: Increase Disk Size

Each cloud image comes with ~2GB of space, this will fill very quickly.

-> qemu-img info virtioa.qcow2
image: virtioa.qcow2
file format: qcow2
virtual size: 2 GiB (2147483648 bytes)
disk size: 267 MiB
cluster_size: 65536
Format specific information:
    compat: 1.1
    lazy refcounts: false
    refcount bits: 16
    corrupt: false

We can increase the image size so that more space will be available

-> qemu-img resize virtioa.qcow2 20G
Image resized.

We can verify the new size

-> qemu-img info virtioa.qcow2
image: virtioa.qcow2
file format: qcow2
virtual size: 20 GiB (21474836480 bytes)
disk size: 267 MiB
cluster_size: 65536
Format specific information:
    compat: 1.1
    lazy refcounts: false
    refcount bits: 16
    corrupt: false

This will not expand the partition or filesystem, it will just simply increase the size of the disk. Cloud-init will take care of expanding to take up the remaining free space when it boots

Optional: Install Packages

It’s super helpful to have VMs start off with all the useful packages for labbing, eg mtr, netcat-openbsd, etc.

With the help of virt-customize we can do this to our image so that any VM started from our image will already have these installed

-> virt-customize -a virtioa.qcow2 --install mtr,netcat-openbsd,inetutils-traceroute,iperf3,tcpdump,dnsutils,nmap,neovim,curl,wget
[   0.0] Examining the guest ...
[   4.6] Setting a random seed
virt-customize: warning: random seed could not be set for this type of
guest
[   4.7] Installing packages: mtr netcat-openbsd inetutils-traceroute iperf3 tcpdump dnsutils nmap neovim curl wget
[  11.6] Finishing off

Clear Machine-ID

The VMs that will be started from the cloud image will all have the same machine-id, which will causes MAC addresses to be the same, etc. We need to clear this, so that it will be regenerated for every VM that’s started from the image

-> virt-customize -a virtioa.qcow2 --truncate /etc/machine-id
[   0.0] Examining the guest ...
[   5.5] Setting a random seed
[   5.6] Setting the machine ID in /etc/machine-id
[   5.6] Truncating: /etc/machine-id
[   5.6] Finishing off

Create Cloud-Init ISO

Cloud-Init allows you to pass configuration to the operating system that will be executed on first boot.

In EVE-NG we need to create an iSO file that contains our cloud-init data, this will then be mounted by the VM and then executed when the node first boots

We will need to create two files: meta-data and user-data

meta-data

instance-id: node

user-data

#cloud-config
password: lab
chpasswd: { expire: False }
ssh_pwauth: True

Refer to Cloud-Init’s Module Reference and Examples for more configuration options

Generate iSO

After both files are created, we can create the iSO file that will store them, and will be mounted by the VM

-> genisoimage -output cdrom.iso -volid cidata -joliet -rock user-data meta-data
I: -input-charset not specified, using utf-8 (detected in locale settings)
Total translation table size: 0
Total rockridge attributes bytes: 331
Total directory bytes: 0
Path table size(bytes): 10
Max brk space used 0
183 extents written (0 MB)

After the cdrom.iso is created, we can copy it to the image location

cp cdrom.iso /opt/unetlab/addons/qemu/linux-cloud-ubuntu-20.04.3
cp cdrom.iso /opt/unetlab/addons/qemu/linux-cloud-debian12

Fix Permissions

As with all EVE-NG images, we need to run fixpermissions

/opt/unetlab/wrappers/unl_wrapper -a fixpermissions

Deploy Node

Return to your EVE-NG Lab and launch a node, you will find these cloud images under Linux Cloud, then in the Image dropdown you can select the one you want.

Once that’s added to the toplogy, you can start it. Wait for it to come to the login prompt.

Each image will have a default username, so you’ll need to use that along with the password you set in user-data, eg ubuntu / lab.

• Ubuntu: ubuntu
• Debian: debian