FQDN and hostname of a virtual machine

When you create a virtual machine (VM), the service assigns an FQDN to this VM. By using this FQDN, other VMs can access your VM within a single network. You can configure the FQDN on your own or you can use the default FQDN:

The format of the default FQDN is the following:
<VM_ID>.<VM_network_ID>.compute.internal.
In this case, the FQDN (as well as the VM’s ID) is only known after the VM is created.
The format of a custom FQDN is the following:
<hostname>.<VM_network_ID>.compute.internal.
You can set the hostname when you create or update a VM.

You can configure an FQDN, but you cannot delete it. The guest OS hostname of the VM is set up during the VM creation; it matches the FQDN. If the FQDN is changed later, the guest OS hostname does not change; and it remains the same as the FQDN was when the VM was created.

Prerequisites

CLI
Terraform
Go SDK
Python SDK
JavaScript SDK

Install and configure the Nebius AI Cloud CLI.

How to get an FQDN

CLI
Go SDK
Python SDK
JavaScript SDK

To get an FQDN of a VM, run the following command:

nebius compute instance get-by-name \
  --name <VM_name> \
  --format json \
  | jq -r '.status.network_interfaces[0].fqdn | split("/")[0]'

The FQDN is specified in the status.network_interfaces.fqdn field of the output.

Get an FQDN of a VM:

fqdnInstance, err := sdk.Services().Compute().V1().
    Instance().GetByName(
        ctx,
        &common.GetByNameRequest{
            Name: "<VM_name>",
        },
    )
if err != nil {
    return err
}
fqdn := fqdnInstance.GetStatus().GetNetworkInterfaces()[0].GetFqdn()
fmt.Println(strings.Split(fqdn, "/")[0])

Get an FQDN of a VM:

fqdn_service = InstanceServiceClient(sdk)
fqdn_instance = await fqdn_service.get_by_name(
    GetByNameRequest(name="<VM_name>"),
)
fqdn = fqdn_instance.status.network_interfaces[0].fqdn
print(fqdn.split("/")[0])

Get an FQDN of a VM:

const fqdnInstanceService = new InstanceService(sdk);
const fqdnInstance = await fqdnInstanceService.getByName(
  GetByNameRequest.create({
    name: "<VM_name>",
  }),
);
const fqdn = fqdnInstance.status?.networkInterfaces[0]?.fqdn;
console.log(fqdn?.split("/")[0]);

How to customize an FQDN

If you do not want to use the default FQDN, you can use your own hostname instead of the VM’s ID. To customize an FQDN, use the hostname parameter:

CLI
Terraform
Go SDK
Python SDK
JavaScript SDK

Create a VM with a customized FQDN:

nebius compute instance create \
   ... \
   --hostname <FQDN_prefix>

Change an FQDN of an existing VM:

nebius compute instance update --id <VM_ID> --hostname <FQDN_prefix>

Use the following VM configuration:

resource "nebius_compute_v1_instance" "my_vm" {
  ...
  hostname = "<FQDN_prefix>"
  ...
}

For more information, see Create a VM.

Create a VM with a customized FQDN:

instanceOperation, err := sdk.Services().Compute().V1().
    Instance().Create(
        ctx,
        &compute.CreateInstanceRequest{
            Metadata: &common.ResourceMetadata{
                Name: "vm-for-scenario",
            },
            Spec: &compute.InstanceSpec{
                Resources: &compute.ResourcesSpec{
                    Platform: "cpu-d3",
                    Size: &compute.ResourcesSpec_Preset{
                        Preset: "4vcpu-16gb",
                    },
                },
                BootDisk: &compute.AttachedDiskSpec{
                    AttachMode: compute.AttachedDiskSpec_READ_WRITE,
                    DeviceId:   "my-device",
                    Type: &compute.AttachedDiskSpec_ExistingDisk{
                        ExistingDisk: &compute.ExistingDisk{
                            Id: bootDiskID,
                        },
                    },
                },
                NetworkInterfaces: []*compute.NetworkInterfaceSpec{
                    {
                        Name:           "eth0",
                        SubnetId:       subnetID,
                        IpAddress:      &compute.IPAddress{},
                        PublicIpAddress: &compute.PublicIPAddress{},
                    },
                },
                Hostname: "<FQDN_prefix>",
            },
        },
    )
if err != nil {
    return err
}
if _, err = instanceOperation.Wait(ctx); err != nil {
    return err
}
vmID := instanceOperation.ResourceID()

Change an FQDN of an existing VM:

instance, err = sdk.Services().Compute().V1().
    Instance().Get(
        ctx,
        &compute.GetInstanceRequest{
            Id: "<VM_ID>",
        },
    )
if err != nil {
    return err
}
if instance.GetSpec() == nil {
    return errors.New("instance spec is missing")
}
instance.Spec.Hostname = "<FQDN_prefix>"
instanceOperation, err = sdk.Services().Compute().V1().
    Instance().Update(
        ctx,
        &compute.UpdateInstanceRequest{
            Metadata: instance.Metadata,
            Spec:     instance.Spec,
        },
    )
if err != nil {
    return err
}
if _, err = instanceOperation.Wait(ctx); err != nil {
    return err
}

Create a VM with a customized FQDN:

instance_service = InstanceServiceClient(sdk)
create_instance_operation = await instance_service.create(
    CreateInstanceRequest(
        metadata=ResourceMetadata(name="vm-for-scenario"),
        spec=InstanceSpec(
            resources=ResourcesSpec(
                platform="cpu-d3",
                preset="4vcpu-16gb",
            ),
            boot_disk=AttachedDiskSpec(
                attach_mode=AttachedDiskSpec.AttachMode.READ_WRITE,
                existing_disk=ExistingDisk(id=boot_disk_id),
                device_id="my-device",
            ),
            network_interfaces=[
                NetworkInterfaceSpec(
                    name="eth0",
                    subnet_id=subnet_id,
                    ip_address=IPAddress(),
                    public_ip_address=PublicIPAddress(),
                ),
            ],
            hostname="<FQDN_prefix>",
        ),
    ),
)
await create_instance_operation.wait()
vm_id = create_instance_operation.resource_id

Change an FQDN of an existing VM:

instance_service = InstanceServiceClient(sdk)
instance = await instance_service.get(
    GetInstanceRequest(id="<VM_ID>"),
)
if instance.spec is None:
    raise ValueError("instance spec is missing")
instance.spec.hostname = "<FQDN_prefix>"
update_instance_operation = await instance_service.update(
    UpdateInstanceRequest(
        metadata=instance.metadata,
        spec=instance.spec,
    ),
)
await update_instance_operation.wait()

Create a VM with a customized FQDN:

const instanceService = new InstanceService(sdk);
const createInstanceOperation = await instanceService.create(
  CreateInstanceRequest.create({
    metadata: ResourceMetadata.create({
      name: "vm-for-scenario",
    }),
    spec: InstanceSpec.create({
      resources: ResourcesSpec.create({
        platform: "cpu-d3",
        size: {
          $case: "preset",
          preset: "4vcpu-16gb",
        },
      }),
      bootDisk: AttachedDiskSpec.create({
        attachMode: AttachedDiskSpec_AttachMode.READ_WRITE,
        deviceId: "my-device",
        type: {
          $case: "existingDisk",
          existingDisk: ExistingDisk.create({
            id: bootDiskId,
          }),
        },
      }),
      networkInterfaces: [
        NetworkInterfaceSpec.create({
          name: "eth0",
          subnetId: subnetId,
          ipAddress: IPAddress.create({}),
          publicIpAddress: PublicIPAddress.create({}),
        }),
      ],
      hostname: "<FQDN_prefix>",
    }),
  }),
).result;
await createInstanceOperation.wait();
const vmId = createInstanceOperation.resourceId();

Change an FQDN of an existing VM:

const updateInstanceService = new InstanceService(sdk);
const instanceForHostname = await updateInstanceService.get(
  GetInstanceRequest.create({
    id: "<VM_ID>",
  }),
);
if (!instanceForHostname.spec) {
  throw new Error("instance spec is missing");
}
instanceForHostname.spec.hostname = "<FQDN_prefix>";
const updateInstanceOperation = await updateInstanceService.update(
  UpdateInstanceRequest.create({
    metadata: instanceForHostname.metadata,
    spec: instanceForHostname.spec,
  }),
).result;
await updateInstanceOperation.wait();

The hostname must be unique, and it cannot contain a full stop (.). For example, if you set hostname to my-host, the FQDN is the following:

my-host.vpcnetwork-e00***.compute.internal.

If you do not set hostname, the VM’s ID is used instead of the hostname, according to the default FQDN.

Virtual machines

Slurm and Soperator in Nebius AI Cloud

Managed Service for Kubernetes®

FQDN and hostname of a virtual machine

Prerequisites

How to get an FQDN

How to customize an FQDN

​Prerequisites

​How to get an FQDN

​How to customize an FQDN

Prerequisites

How to get an FQDN

How to customize an FQDN