virt-lightning 2.5.0
Deploy your testing VM in a couple of seconds
Requires Python: >=3.9
Keywords: libvirt, cloud, qemu, cloudinit

# 🗲 spawn Cloud instances on libvirt!🗲


[![PyPI version](https://badge.fury.io/py/virt-lightning.svg)](https://badge.fury.io/py/virt-lightning)
[![Documentation](https://shields.io/static/v1?message=Documentation&color=blue)](https://virt-lightning.org/)

![Logo](./logo/logo_no_text.png)

You want to spawn local VM quickly.. Like... really quickly. You want them to be as generic as possible. Actually you would like to reuse some existing cloud images!

This is the right tool for you.

Virt-Lightning exposes a CLI inspired by the Cloud and Vagrant.
It can also prepare the Ansible inventory file.

This is handy to quickly validate a new Ansible playbook, or a role on a large number of environments.

### example: less than 30 seconds to spawn an instance ⚡

In a nutshell:

```shell
echo "- distro: centos-7" > virt-lightning.yaml
vl up
vl ansible_inventory > inventory
ansible all -m ping -i inventory
```

### example: or 75 seconds for 10 nodes lab ⚡

During this recording, we:

1. use the list of distributions to generate a virt-lightning.yaml file.
2. we then create an environment based on this file
3. once the environment is ready, we generate an Ansible inventory file
4. and we use it to call Ansible's ping module on all the host.

[![demo](https://asciinema.org/a/230671.svg)](https://asciinema.org/a/230671?autoplay=1)


## Requirements
- Python 3.8 or greater
- The Python3 binding for libvirt, the package is probably called `python3-libvirt` or `libvirt-python` according to pip.
- Libvirt must be running, most of the time you just need to run: `sudo systemctl start --now libvirtd`
- Finally, be sure your user can access the system libvirt daemon, e.g with: `virsh -c qemu:///system`

## Optional
- You make also want to install `python3-urwid` if you want to get the fancy list of VMs. This dependency is optional.


## Installation (Fedora/RHEL)

```shell
sudo dnf install uv python3-libvirt libvirt-devel gcc python3-devel
uvx virt-lightning
```

## Installation (Fedora Atomic, e.g Silverblue)

Virt-Lightning won't work from toolbox or a container.


``` shell
rpm-ostree install genisoimage libvirt libvirt-client libvirt-daemon-kvm python3-libvirt
systemctl reboot
(...)
sudo systemctl enable --now libvirtd
sudo systemctl enable --now virtqemud.socket
sudo systemctl enable --now virtnetworkd.socket
sudo systemctl enable --now virtstoraged.socket

# You can also layer pipx
python3 -m venv venv --system-site-packages
./venv/bin/pip install virt-lightning
./venv/bin/vl
```

## Installation (Debian/Ubuntu)

```shell
sudo apt install uv python3-venv pkg-config gcc libvirt-dev python3-dev
uvx install virt-lightning
```

## Post Installation

`virt-lightning` will be installed in ~/.local/bin/. Add it in your `$PATH` if
it's not already the case. For instance you can use:

```shell
echo "export PATH=$PATH:~/.local/bin/" >> ~/.bashrc
source ~/.bashrc
```

# List Remote Images

Before you start your first VM, you need to list the images. To do so,
you just use the `vl remote_images` command:

```shell
$ vl remote_images
```

# Fetch some images

Before you start your first VM, you need to fetch the images. To do so,
you just use the `vl pull` command:

```shell
$ vl pull fedora-32
```

You can also pull an image from Internet, as soon as it's a `.qcow2` or a `.qcow2.xz` (compress with `xz`):

```shell
$ vl pull freebsd-16-current --url https://download.freebsd.org/snapshots/VM-IMAGES/16.0-CURRENT/amd64/Latest/FreeBSD-16.0-CURRENT-amd64-BASIC-CLOUDINIT-ufs.qcow2.xz
```

# Actions

`vl` is an alias for `virt-lightning`, you can use both. In the rest of the document
we use the shortest version.

## **vl images**

List the distro images that can be used. Its output is compatible with `vl up`. You can initialize a new configuration with: `vl images > virt-lightning.yaml`.

## **vl up**

`virt-lightning` will read the `virt-lightning.yaml` file from the current directory and prepare the associated VM.

## **vl down**

Destroy all the VMs managed by Virt-Lightning.

## **vl start**

Start a specific VM, without reading the `virt-lightning.yaml` file.

## **vl stop**

Stop just one VM.

## **vl status**

List the VMs, their IP and if they are reachable.

## **vl ansible_inventory**

Export an inventory in the Ansible format.

**Note:** Created VMs use various Python versions, which can cause compatibility issues with the Ansible version on the control node (host). In case of errors related to Python version compatibility, please consult the Ansible n[changelog](https://docs.ansible.com/ansible/latest/reference_appendices/release_and_maintenance.html) for details on supported Python versions.

In can you need a different Python version for a given image (`ansible_python_interpreter`), you can define it in a YAML file aside of the qcow2 image. E.g:

```
$ ls -l /var/lib/virt-lightning/pool/upstream/netbsd-10.0.qcow2
-rw-r--r--. 1 qemu qemu 242483200 Nov  5 18:50 /var/lib/virt-lightning/pool/upstream/netbsd-10.0.qcow2
$ cat /var/lib/virt-lightning/pool/upstream/netbsd-10.0.yaml
python_interpreter: /usr/pkg/bin/python3.12

```

## **vl ssh**

Show up a menu to select a host and open a ssh connection.

[![vl ssh](https://asciinema.org/a/230675.svg)](https://asciinema.org/a/230675?autoplay=1)

## **vl console**

Like `vl ssh` but with the serial console of the VM.

[![vl ssh](https://asciinema.org/a/230677.svg)](https://asciinema.org/a/230677?autoplay=1)


## **vl viewer**

Like `vl console` but with the SPICE console of the VM. Requires `virt-viewer`.

## **vl pull**

Download a VM image. Use the `vl remote_images` to get a list of available images. You can also update the custom configuration to add a private image hub.

# Configuration

## Global configuration

If `~/.config/virt-lightning/config.ini` exists, Virt-Lightning will read
its configuration there.

```ini
[main]
network_name = virt-lightning
root_password = root
storage_pool = virt-lightning
network_auto_clean_up = True
ssh_key_file = ~/.ssh/id_rsa.pub
```

**network_name**: if you want to use an alternative libvirt network

**root_password**: the root password

**storage_pool**: if you want to use an alternative libvirt storage pool

**network_auto_clean_up**: if you want to automatically remove a network when running `virt-lightning down`

**ssh_key_file**: if you want to use an alternative public key

**private_hub**: if you need to set additional url from where images should be retrieved, update the configuration file `~/.config/virt-lightning/config.ini` adding the following
```
[main]
private_hub=url1,url2
```

**custom_image_list**: if you wish to use a custom image list, update the configuration file `~/.config/virt-lightning/config.ini` adding the following
```
[main]
custom_image_url=<url>/images.json
```
take a look at [images.json](virt-lightning.org/images.json) for a reference

## VM configuration keys

A VM can be tuned at two different places with the following keys:

- `distro`: the name of the base distro image to use, it's the only mandatory parameter.
- `name`: the VM name
- `memory`: the amount of memory to dedicate to the VM
- `vcpus`: the number of vcpu to dedicate to the VM
- `root_password`: the root password in clear text
- `ssh_key_file`: the path of the public key for connecting to the VM. If the value, Virt-Lightning will pick the first key matching `~/.ssh/id_*.pub`.
- `groups`: this list of groups will be used if you generate an Ansible inventory.
- `disks`: a list of disks to create and attach to the VM. The first one is used as the root disk. Default to `[{"size": 15}]`
    - `size` the size of the disk in GB. Default is `1`.
- `networks`: a list of network to attach to the VM. The default is: one virtio interface attached to `virt-lightning` network.
    - `network`: the name of the libvirt network. Default is the key `network_name` from the configuration (`virt-lightning` by default). The key cannot be used with `bridge`. A host variable is added to in the Ansible inventory, with the network name with suffix "_ipv4" as key and the IPv4 as value, e.g. "private_ipv4".
    - `ipv4`: a static IPv4. Default is a dynamic IPv4 address.
    - `nic_model`: the libvirt driver to use. Default is `virtio`
    - `mac`: an optional static MAC address, e.g: '52:54:00:71:b1:b6'
    - `bridge`: optional, the name of a bridge to connect to. This key replace the `network` key.
    - `virtualport_type`: The type of the virtualport, currently, this can be used with `bridge`.

### Example: a `virt-lightning.yaml` file:

```yaml
- name: esxi-vcenter
  distro: esxi-6.7
  memory: 12000
  root_disk_size: 30
  vcpus: 2
  root_password: '!234AaAa56'
  groups: ['all_esxi']
- name: esxi1
  distro: esxi-6.7
  memory: 4096
  vcpus: 1
  root_password: '!234AaAa56'
  groups: ['all_esxi', 'esxi_lab']
- name: esxi2
  distro: esxi-6.7
  memory: 4096
  vcpus: 1
  root_password: '!234AaAa56'
  groups: ['all_esxi', 'esxi_lab']
- name: centos-7
  distro: centos-7
  networks:
    - network: default
      ipv4: 192.168.122.50
  bootcmd:
    - yum update -y
```

### Example: connect to an OpenvSwitch bridge

```yaml
- name: controller
  distro: fedora-35
  - bridge: my-ovs-bridge-name
    virtualport_type: openvswitch
```

### Example: To getting DHCP working with a bridge connection

```yaml
- name: vlvm-fedora-40
  distro: fedora-40
  networks:
    - network: virt-lightning
      nic_model: virtio
    - bridge: br0
      nic_model: virtio
```

### Example: Addressing multiple interfaces
```yaml
- name: example
  distro: fedora-40
  networks:
    - network: default
      ipv4: 192.168.122.50
    - network: management
      ipv4: 192.168.123.50
```

The variable `management_ipv4` holds the IP address and netmask.
```yaml
- hosts: all
  tasks:
    - name: Default address
      debug: msg="{{ ansible_host }}"
      # "msg": "192.168.122.50"
    - name: Management address
      debug: msg="{{ management_ipv4 }}"
      # "msg": "192.168.123.50/24"
    - name: Management address
      debug: msg="{{ management_ipv4 | ansible.utils.ipaddr('address') }}"
      # "msg": "192.168.123.50"
    - name: Management address
      debug: msg="{{ management_ipv4 | ansible.utils.ipaddr('netmask') }}"
      # "msg": "255.255.255.0"
```

### You can also associate some parameters to the distro image itself

```shell
cat /var/lib/virt-lightning/pool/upstream/esxi-6.7.yaml
username: root
python_interpreter: /bin/python
memory: 4096
networks:
  - network: virt-lightning
    nic_model: virtio
  - network: default
    nic_model: e1000
```

### Example: working with snapshots

User can create a snapshot of VM to restore it later. Default configuration of `virt-lightning` supports snapshots both
for running and powering off VMs. `qcow2` disk format used allows diskspace-wise incremental snapshotting, keeping only
updated storage blocks. `virsh` tool supports it by CLI, `virt-manager` provides a neat GUI supporting most of
the features
```shell
# create first snapshot of running machine
virsh snapshot-create-as --domain vm_name --name snapshot_1
# create second snapshot
virsh snapshot-create-as --domain vm_name --name snapshot_2
# validate that both of them were saved
virsh snapshot-list vm_name
# and revert to the first one
virsh snapshot-revert vm_name --snapshotname snapshot_1
```

### Development

install libvirt-dev package:

Debian/Ubuntu:
```shell
apt install python3-venv pkg-config gcc libvirt-dev python3-dev
```

Fedora/RHEL:
```shell
dnf install python3-devel gcc libvirt-devel
```

You can run a development copy in a virtual env:
```shell
uv run virt-lightning
```

### Add a new image or refresh the list

You just need to adjust the `virt-lightning.org/refresh.py` script and call it with:

```shell
uv run virt-lightning.org/refresh.py
```