libvirt-VM-info

Listens for libvirt events and displays the relevant information of the VM.

The information displayed is:

• VM name
• the VM state
• allocated CPU number
• allocated and max memory
• disks and their source
• the list of network interfaces with their IP addresses

Implementation

• The code is written in Python using the libvirt-python library.
• The VIR_DOMAIN_EVENT_MAPPING and VIR_DOMAIN_STATE_MAPPING in constants.py file is based on the enum defined in libvirt codebase in include/libvirt/libvirt-domain.h files. (Source L51, L3014)
• A default event is registered and virEventRunDefaultImpl() is invoked in a loop to process events. source
• A callback domainEventRegisterAny is added to receive notification on any event, upon which the relevant information is displayed.
• The information is displayed following the documentation of the library.

Installation Instructions

Make sure your system supports Virtualization

- sudo apt install qemu qemu-kvm libvirt-bin bridge-utils virt-manager
- sudo service libvirtd start
- sudo update-rc.d libvirtd enable
- sudo nano /etc/netplan/01-netcfg.yaml

Add the following:

network:
    ethernets:
        ens33:
            addresses: [192.168.0.51/24]
            gateway4: 192.168.0.1
            nameservers:
              addresses: [192.168.0.1]
            dhcp4: no
            optional: true
    version: 2

- sudo netplan apply
- sudo pip install libvirt-python

Detailed instructions on installation: here

Steps to Run

• Spin a VM to test the code, I installed Ubuntu18.04 without graphics, feel free to use any.

sudo virt-install \
--name falcon \
--description "Test VM with Ubuntu" \
--os-type Linux \
--os-variant ubuntu18.04 \
--ram 1024 \
--vcpus 1 \
--disk path=/var/lib/libvirt/images/falcon1.img,size=8 \
--graphics none \
--location 'http://archive.ubuntu.com/ubuntu/dists/bionic/main/installer-amd64/' \
--extra-args "console=ttyS0,115200n8"

• Follow the steps on the terminal to complete the installation of the OS on the VM
• Check if it's correctly setup using: sudo virsh list --all

- git clone https://github.com/mishal23/libvirt-VM-info
- sudo python main.py

• On another terminal invoke any event for the VM and it'll display the information.

Acknowledgment

Thanks to @cbosdo & @zippy2 for giving their valuable feedback on the code.