Just a snippet of code to upload a VM image to libvirt using python

upload_qcow2_to_libvirt.py

#!/bin/env python3
import libvirt
import pathlib

conn = libvirt.open("qemu:///system")
template_pool = conn.storagePoolLookupByName("default")
image_filename = "fedora-cloud-base-38-x86_64.qcow2"
spool_file = pathlib.Path("Fedora-Cloud-Base-38-1.6.x86_64.qcow2")

# Size from output of `qemu-img info --output=json Fedora-Cloud-Base-38-1.6.x86_64.qcow2`
image_size = 497291264
image_vsize = 5368709120
stgvol_xml = f"""
<volume>
  <name>{image_filename}</name>
  <allocation>{ image_size }</allocation>
  <capacity unit="bytes">{image_vsize}</capacity>
</volume>"""

stgvol = template_pool.createXML(stgvol_xml, 0)

def stream_handler(stream, data, file_):
    return file_.read(data)

stream = conn.newStream(0)
stgvol.upload(stream, 0, 0)
with spool_file.open(mode="rb") as f:
    stream.sendAll(stream_handler, f)
    stream.finish()