Enabling cloud-init on proxmox qcow2 images

Proxmox is a valuable virtualization platform tham makes it simple to manage and deploy VMs. Cloud-init is an “industry standard multi-distribution method for cross-platform cloud instance initialization”¹.

While Proxmox itself does not support cloud-init out-of-the-box, there are ways to integrate it with your Proxmox environment. There are some extra steps to configure a QEMU image format².

On you proxmox host, you will first need to install libguestfs-tools and the image you want to modify and use. In this example, I get debian 12 generic cloud image.

apt install libguestfs-tools
mkdir -p /var/lib/vz/template/qemu &&  cd /var/lib/vz/template/qemu
wget https://cloud.debian.org/images/cloud/bookworm/20250316-2053//debian-12-genericcloud-amd64-20250316-2053.qcow2

Now that the image is downloaded, we need to patch it with virt-edit to add the cloud-init files.

virt-edit debian-12-genericcloud-amd64-20250316-2053.qcow2  /etc/cloud/cloud.cfg
virt-edit debian-12-genericcloud-amd64-20250316-2053.qcow2  /etc/ssh/sshd_config
virt-edit debian-12-genericcloud-amd64-20250316-2053.qcow2  /etc/motd

Now we will import the raw image into proxmox, and mark it as having cloud-init support:

qm importdisk 100 ./debian-12-genericcloud-amd64-20250316-2053.qcow2 local-lvm
qm set 100 --ide2 local-lvm:cloudinit