Tutorial: Create and manage a Linux VM in VM Runtime on GDC

This tutorial shows you how to create and manage a Linux virtual machine (VM) on a new installation of VM Runtime on GDC. You learn the process to create and define the basic dependencies such as a StorageClass and virtual network, then create a VM that uses these resources. You then learn how to edit the VM, such as to add a new disk.

Objectives

Configure basic dependencies
- Create a StorageClass for VM Runtime on GDC
- Create a virtual network for your VMs to use
Create a virtual machine boot disk
Create a VM
Edit a VM to add a new virtual disk

Before you begin

To complete this tutorial, you need access to the following resources and tools:

Access to Google Distributed Cloud version 1.12.0 (anthosBareMetalVersion: 1.12.0) or higher cluster. You can use any cluster type capable of running workloads. If needed, try Google Distributed Cloud on Compute Engine or see the cluster creation overview.
The virtctl client tool installed as a plugin for kubectl. If needed, install the virtctl client tool.

Create a `StorageClass`

You use a StorageClass to define the type of storage you make available to VMs. Different storage classes might map to a different type of storage hardware, file system, or performance.

It's beyond the scope of this tutorial to provide specific instructions for each StorageClass and storage partner.

Google Distributed Cloud Ready storage partners provide qualified Container Storage Interface (CSI) drivers that install and configure the required custom resources for your storage. To install the CSI driver in your cluster, review the list of supported storage partners and follow their instructions.

After you install the CSI driver for your storage platform, one or more storage classes are available in your cluster. You use one of these storage classes to create a virtual hard disk in this tutorial.

The following basic example NFS StorageClass uses the NFS CSI Driver. You define the NFS server address and path to use in the StorageClass. All the nodes in your cluster can then connect to and use this NFS storage:

  apiVersion: storage.k8s.io/v1
  kind: StorageClass
  metadata:
    name: example-nfs
  provisioner: nfs.csi.k8s.io
  parameters:
    server: nfs-server.example.com
    path: /vm-share
  reclaimPolicy: Delete
  volumeBindingMode: Immediate
  mountOptions:
    - nconnect=8
    - nfsvers=4.1

In this tutorial, use the name of a StorageClass in your own cluster.

VM Runtime on GDC automatically generates one storage profile for each StorageClass in a cluster. The storage profile is the same name as the associated StorageClass. Storage profiles provide extra configuration options associated with each StorageClass. For more information about storage profiles, including configuration instructions, see Configure storage profiles.

Create a virtual network

VMs connect to a virtual network using a virtual network interface. The virtual network lets them communicate with other VMs in the cluster, or to resources outside of the cluster.

In this tutorial, you create a basic Layer 2 (L2) virtual network that can use an external DHCP server. When you enable the use of an external DHCP server, you can skip configuration of DNS and gateway settings if they're provided by DHCP.

To create a network that uses an external DHCP server, complete the following steps:

Create a Network manifest, such as dhcp-network.yaml, in the editor of your choice:
```
nano dhcp-network.yaml
```
Copy and paste the following YAML manifest:
```
apiVersion: networking.gke.io/v1
kind: Network
metadata:
  name: NETWORK_NAME
spec:
  type: L2
  nodeInterfaceMatcher:
    interfaceName: INTERFACE_NAME
  externalDHCP4: true
```
Replace the following values:
- NETWORK_NAME: the name for your network.
- INTERFACE_NAME: the interface name on your Google Distributed Cloud node to attach the network to. All nodes should have the same interface name.
In this Network manifest, the following values are set:
- Workloads can have only an L2 attachment to this network. This is the only network type that you can create in VM Runtime on GDC.
- The network has external DHCP enabled. The external DHCP server is responsible for IPv4 address allocation, routes, gateway, and DNS configuration for workloads connected to this network.
Save and close the Network manifest in your editor.
Create the network using kubectl:
```
kubectl apply -f use-dhcp-network.yaml
```

Create a VM boot disk

A VM can use a precreated disk image, or boot from an ISO image to manually install the OS. These disk images can be stored and accessed using HTTP, or in Cloud Storage and accessed using a Secret.

In this tutorial, you create a boot disk from the public Ubuntu Server 20.04 cloud image using HTTP.

To create a disk from an image, complete the following steps.

Create a VirtualMachineDisk manifest, such as my-disk.yaml, in the editor of your choice:
```
nano my-disk.yaml
```
Copy and paste the following YAML definition:
```
apiVersion: vm.cluster.gke.io/v1
kind: VirtualMachineDisk
metadata:
  name: DISK_NAME
spec:
  size: 20Gi
  storageClassName: STORAGE_CLASS_NAME
  source:
    http:
      url: https://cloud-images.ubuntu.com/releases/focal/release/ubuntu-20.04-server-cloudimg-amd64.img
```
Replace the following values:
- DISK_NAME: the name that you want for your disk. This example creates a 20Gi (20 gibibyte) disk named DISK_NAME using a public Ubuntu Server 20.04 image.
- STORAGE_CLASS_NAME: the StorageClass that you want to use for your VirtualMachineDisk.
  - Use kubectl get storageclass to list what's available in your cluster.
Note: It can take 15–20 minutes to download this public image, create the VirtualMachineDisk, and apply the OS image to the new disk. The process to create the VirtualMachineDisk is much faster when you use a locally stored image. For most production scenarios, use a local HTTP image repository rather than pull from an external public source each time.
Save and close the VirtualMachineDisk manifest in your editor.
Create the disk using kubectl:
```
kubectl apply -f my-disk.yaml
```

Create a VM

With a virtual network and boot disk created in the previous sections, now create a VM. The VM connects to the virtual network, and boots from the virtual disk. The following instructions create a VM by directly applying a VirtualMachine YAML manifest file with the kubectl CLI.

Create a manifest that defines a VirtualMachine, such as my-vm.yaml, in the editor of your choice:
```
nano my-vm.yaml
```
Copy and paste the following YAML definition:
```
apiVersion: vm.cluster.gke.io/v1
kind: VirtualMachine
metadata:
  name: VM_NAME
spec:
  osType: linux
  compute:
    cpu:
      vcpus: VCPU_NUMBER
    memory:
      capacity: MEMORY_SIZE
  interfaces:
    - name: eth0
      networkName: NETWORK_NAME
      default: true
  disks:
    - boot: true
      virtualMachineDiskName: DISK_NAME
```
Replace the following values:
- VM_NAME: the name for your VM.
- VCPU_NUMBER: The optional number of vCPUs to assign to the VM. Without this setting, the default of 2 vCPUs is assigned.
  - You can assign between 1 and 96 vCPUs to a VM.
- MEMORY_SIZE: The optional amount of memory to assign to the VM. Without this setting, the default of 4 GiB of memory is assigned.
  - You can assign between 1M and 1T of memory to a VM. For more information, see Memory resource units.
- NETWORK_NAME: the name of your network created in a previous section.
- DISK_NAME: the name of your boot disk created in the previous section. This disk is set to boot: true.
Save and close the manifest in your editor.
Create the VM and disk using kubectl:
```
kubectl apply -f my-vm.yaml
```
It can take a few minutes to create the VM. Check the status of the VM with the kubectl command:
```
kubectl get gvm VM_NAME
```
The following example output shows the VM in a Running state:
```
NAME    STATUS    AGE   IP
MY_VM   Running   64s   192.168.2.124
```

Connect to the VM

When your VM is running, connect to the console of the VM. This console connection lets you perform basic tasks such as to further configure the VM or install an application.

To access a VM from the console, use kubectl:
```
kubectl virt console VM_NAME
```
When prompted, enter the user credentials that you specified to create the VM.
After you successfully connect to the console of the VM, exit the VM session and console:
```
Ctrl + ]
```

Edit the VM

During the lifecycle of your VM, you might want to edit your VM. For example, you might want to add storage to install an application on a dedicated disk, or use additional storage for your application.

In this tutorial, create a blank disk and attach it to the VM. This scenario lets you create a data disk to store application data.

Create a VirtualMachineDisk manifest, such as my-data-disk.yaml, in the editor of your choice:
```
nano my-data-disk.yaml
```
Copy and paste the following YAML definition:
```
apiVersion: vm.cluster.gke.io/v1
kind: VirtualMachineDisk
metadata:
  name: DATA_DISK_NAME
spec:
  size: 10Gi
  storageClassName: STORAGE_CLASS_NAME
```
Replace the following values:
- DATA_DISK_NAME: the name that you want for your data disk. This example creates a 10Gi (10 gibibyte) disk.
- STORAGE_CLASS_NAME: the StorageClass that you want to use for your VirtualMachineDisk.
  - Use kubectl get storageclass to list what's available in your cluster.
Save and close the disk manifest in your editor.
Create the disk using kubectl:
```
kubectl apply -f my-data-disk.yaml
```
Use kubectl to stop your VM before you attach the new virtual disk:
```
kubectl virt stop VM_NAME
```

Edit your VM resource:

kubectl edit gvm VM_NAME

Update the VirtualMachine YAML manifest to attach the disk at the end of the VM's spec.disks section:

apiVersion: vm.cluster.gke.io/v1
kind: VirtualMachine
metadata:
  name: VM_NAME
spec:
  ...
  disks:
    - boot: true
      virtualMachineDiskName: DISK_NAME
    - virtualMachineDiskName: DATA_DISK_NAME

Replace DATA_DISK_NAME with the name of your disk created in the previous step.

Save and close the updated VM manifest in your editor.
Use kubectl to start the VM:
```
kubectl virt start VM_NAME
```

Clean up

To delete the resources created in this tutorial, complete the following steps:

Delete your VM:
```
kubectl delete -f my-vm.yaml
```

Delete your VirtualMachineDisk resources:

kubectl delete -f my-data-disk.yaml
kubectl delete -f my-disk.yaml

If you don't want to keep the basic dependencies in your cluster, complete the following steps:

Delete your virtual network:

kubectl delete -f use-dhcp-network.yaml

To remove the CSI driver from your cluster, follow the instructions from your storage partner.