What is the process for utilizing libvirt with Google Compute Engine in TypeScript

Question

Pulumi · Accepted Answer

Libvirt is a toolkit to manage virtualization platforms, and it is typically used with KVM/QEMU on Linux systems. Google Compute Engine (GCE) does not use libvirt directly since it's a cloud provider's virtual machine management system. However, it supports custom images and nested virtualization, which means in theory, you could run libvirt inside a GCE instance to manage other virtual machines or containers.

To accomplish this with Pulumi in TypeScript, you need to set up a Google Compute Engine virtual machine instance with nested virtualization enabled. Once the GCE instance is running, you can install libvirt and use it as you would on any normal Linux server.

Here's a step-by-step explanation of the code:

1. We start by importing the necessary Pulumi and GCE packages.
2. We then create a new VM instance on Google Compute Engine with the specific `machineType` that meets our requirements for running nested VMs.
3. To enable nested virtualization, we configure the `guestAccelerators` property accordingly.
4. Optionally, we add a startup script to the VM's metadata to install libvirt when the instance boots.
5. We also set up the network interfaces allowing the VM to communicate with the outside world.
6. Finally, we export the instance's name and IP address for easy access.

Below is the TypeScript program you would use:

```typescript
import * as gcp from "@pulumi/gcp";

// Create a Google Compute Engine virtual machine instance
const vmInstance = new gcp.compute.Instance("vm-instance", {
    // Define the machine type based on your requirements
    machineType: "e2-standard-2",
    // Specify the zone where the VM instance will be created
    zone: "us-central1-a",
    // Configure the boot disk with the desired image, for example Debian
    bootDisk: {
        initializeParams: {
            image: "debian-cloud/debian-9",
        },
    },
    // Enable nested virtualization by specifying an appropriate guest accelerator (the NVIDIA Tesla P4 in this example)
    guestAccelerators: [{
        type: "nvidia-tesla-p4-vws",
        count: 1
    }],
    // Optionally add a startup script to install libvirt. This step requires a script that installs libvirt.
    metadataStartupScript: `#!/bin/bash
        apt-get update
        apt-get install -y qemu-kvm libvirt-bin virtinst bridge-utils cpu-checker
        adduser $(whoami) kvm
        adduser $(whoami) libvirt
    `,
    // Configure the rest of the VM options, like network
    networkInterfaces: [{
        network: "default",
    }],
});

// Export the instance's name and IP address
export const instanceName = vmInstance.name;
export const instanceAddress = vmInstance.networkInterfaces.apply(ni => ni[0].networkIp);
```

In this code, a new GCE instance is defined with a predefined machine type suitable for nested virtualization (`e2-standard-2`). However, Google's current support and capabilities around nested virtualization may vary, and specialized hardware (as noted by `'nvidia-tesla-p4-vws'`) may not be necessary if you are not doing GPU-related virtualization. The `metadataStartupScript` is a placeholder for a script you would create to install libvirt on the newly created instance.

Please note that the Pulumi program will only define the desired infrastructure. The installation and configuration of libvirt itself, as well as the management of VMs using libvirt inside the Google Compute Engine instance, would be done via the startup script or by logging into the instance after it's been set up and manually setting it up as you would on any standard Linux server.