libvirt

libvirt instance for starting framework

Creating a fully functional script for your request requires breaking down the task into specific steps, following libvirt and SSH configurations. The example assumes you have a basic Fedora cloud image (or similar) ready for use with libvirt and Python installed on your system, along with the libvirt, paramiko (for SSH connection), and potentially os libraries to execute shell commands if needed.

Step 1: Install Python dependencies.

You will need to install libvirt-python and paramiko for SSH interactions. You can install these using pip:

pip install libvirt-python paramiko

Step 2: Define the XML for creating a VM in libvirt.

This script will focus on setting up an initially very basic VM. You must adapt the paths and possibly network interfaces to your needs.

Step 3: Set up an SSH connection to the VM.

This step assumes that your VM image has SSH enabled and that you have the credentials or key to connect.

Here's an example script that combines these steps:

import libvirt
import paramiko
import time

# Connect to the libvirt service
conn = libvirt.open('qemu:///system')
if conn is None:
    raise ValueError('Failed to open connection to qemu:///system')

# Define a basic VM (edit paths and details as necessary)
vm_xml = """
<domain type='kvm'>
  <name>fedora-test</name>
  <memory unit='MiB'>2048</memory>
  <vcpu placement='static'>2</vcpu>
  <os>
    <type arch='x86_64'>hvm</type>
    <boot dev='hd'/>
  </os>
  <disk type='file' device='disk'>
      <driver name='qemu' type='qcow2'/>
      <source file='/var/lib/libvirt/images/Fedora-Cloud-Base.qcow2'/>
      <target dev='vda' bus='virtio'/>
  </disk>
  <!-- Add network interface as per your configuration -->
  <interface type='network'>
    <source network='default'/>
    <model type='virtio'/>
  </interface>
</domain>
"""

# Define the VM
dom = conn.createXML(vm_xml, 0)
if dom is None:
    raise ValueError('Failed to create a domain.')

print(f"VM {dom.name()} is created and booted.")

# Assuming the image has predefined user credentials (e.g., 'fedora' user)
ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())

# Wait a bit for VM to start. In a real script, a more robust check would be appropriate.
time.sleep(30)

try:
    # Adapt these parameters to match your VM's configuration
    ssh.connect('VM_IP', username='fedora', password='your_password')

    stdin, stdout, stderr = ssh.exec_command('echo "Hello from VM!"')
    print(stdout.read().decode())

    ssh.close()
except Exception as e:
    print(f"SSH connection error: {e}")

conn.close()

Please adapt the following in the script to your setup:

• The path to the Fedora image in <source file='/var/lib/libvirt/images/Fedora-Cloud-Base.qcow2'/>.
• The network interface configuration if not using the default.
• The ssh.connect parameters: replace 'VM_IP' with your VM's IP address, 'fedora' with the VM username, and 'your_password' with the actual password or set up key-based authentication.
• Ensure your Fedora cloud image is set up to accept SSH connections and has a user that can log in. This setup varies depending on the image.

This script directly executes a echo command on the VM to demonstrate the SSH connection. For production use, adapt and secure your VM and SSH setup appropriately.