If a VMI is already marked for deleteion, the VM controller is not
allowed to delete the VMI again. If it does we can end up in a rythm
where the vmi controller is always behind the latest modification of the
object and can never remove our finalizer once the vmi pod is gone.

pkg/util/net/dns/sanitize.go

@@ -0,0 +1,44 @@
/*
 * This file is part of the KubeVirt project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * Copyright 2018 Red Hat, Inc.
 *
 */

package dns

import (
	"strings"

	"k8s.io/apimachinery/pkg/util/validation"

	"kubevirt.io/kubevirt/pkg/api/v1"
)

// Sanitize hostname according to DNS label rules
// If the hostname is taken from vmi.Spec.Hostname
// then it already passed DNS label validations.
func SanitizeHostname(vmi *v1.VirtualMachineInstance) string {

	hostName := strings.Split(vmi.Name, ".")[0]
	if len(hostName) > validation.DNS1123LabelMaxLength {
		hostName = hostName[:validation.DNS1123LabelMaxLength]
	}
	if vmi.Spec.Hostname != "" {
		hostName = vmi.Spec.Hostname
	}

	return hostName
}

pkg/virt-api/validating-webhook/validating-webhook.go

@@ -26,12 +26,14 @@ import (
	"io/ioutil"
	"net/http"
	"regexp"
	"strings"

	"k8s.io/apimachinery/pkg/api/resource"

	v1beta1 "k8s.io/api/admission/v1beta1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/apimachinery/pkg/util/validation"
	k8sfield "k8s.io/apimachinery/pkg/util/validation/field"

	"k8s.io/apimachinery/pkg/labels"
@@ -367,6 +369,18 @@ func ValidateVirtualMachineInstanceSpec(field *k8sfield.Path, spec *v1.VirtualMa
		// We won't process anything over the limit
		return causes
	}
	// Validate hostname according to DNS label rules
	if spec.Hostname != "" {
		errors := validation.IsDNS1123Label(spec.Hostname)
		if len(errors) != 0 {
			causes = append(causes, metav1.StatusCause{
				Type: metav1.CauseTypeFieldValueInvalid,
				Message: fmt.Sprintf("%s does not conform to the kubernetes DNS_LABEL rules : %s",
					field.Child("hostname").String(), strings.Join(errors, ", ")),
				Field: field.Child("hostname").String(),
			})
		}
	}

	// Validate memory size if values are not negative
	if spec.Domain.Resources.Requests.Memory().Value() < 0 {

pkg/virt-controller/services/template.go

@@ -32,6 +32,7 @@ import (
	"kubevirt.io/kubevirt/pkg/api/v1"
	"kubevirt.io/kubevirt/pkg/precond"
	"kubevirt.io/kubevirt/pkg/registry-disk"
	"kubevirt.io/kubevirt/pkg/util/net/dns"
)

const configMapName = "kube-system/kubevirt-config"
@@ -303,10 +304,7 @@ func (t *templateService) RenderLaunchManifest(vmi *v1.VirtualMachineInstance) (

	containers = append(containers, container)

	hostName := vmi.Name
	if vmi.Spec.Hostname != "" {
		hostName = vmi.Spec.Hostname
	}
	hostName := dns.SanitizeHostname(vmi)

	// TODO use constants for podLabels
	pod := k8sv1.Pod{

pkg/virt-controller/watch/vm.go

@@ -295,7 +295,7 @@ func (c *VMController) startVMI(vm *virtv1.VirtualMachine) error {
}

func (c *VMController) stopVMI(vm *virtv1.VirtualMachine, vmi *virtv1.VirtualMachineInstance) error {
	if vmi == nil {
	if vmi == nil || vmi.DeletionTimestamp != nil {
		// nothing to do
		return nil
	}

pkg/virt-controller/watch/vm_test.go

@@ -167,6 +167,18 @@ var _ = Describe("VirtualMachine", func() {
			testutils.ExpectEvent(recorder, SuccessfulDeleteVirtualMachineReason)
		})

		It("should not delete the VirtualMachineInstance again if it is already marked for deletion", func() {
			vm, vmi := DefaultVirtualMachine(false)
			vmi.DeletionTimestamp = now()

			addVirtualMachine(vm)
			vmiFeeder.Add(vmi)

			vmInterface.EXPECT().Update(gomock.Any()).Times(1).Return(vm, nil)

			controller.Execute()
		})

		It("should ignore non-matching VMIs", func() {
			vm, vmi := DefaultVirtualMachine(true)

pkg/virt-launcher/virtwrap/manager.go

@@ -39,6 +39,7 @@ import (
	"kubevirt.io/kubevirt/pkg/ephemeral-disk"
	"kubevirt.io/kubevirt/pkg/log"
	"kubevirt.io/kubevirt/pkg/registry-disk"
	"kubevirt.io/kubevirt/pkg/util/net/dns"
	"kubevirt.io/kubevirt/pkg/virt-launcher/virtwrap/api"
	"kubevirt.io/kubevirt/pkg/virt-launcher/virtwrap/cli"
	domainerrors "kubevirt.io/kubevirt/pkg/virt-launcher/virtwrap/errors"
@@ -85,10 +86,7 @@ func (l *LibvirtDomainManager) preStartHook(vmi *v1.VirtualMachineInstance, doma
	// generate cloud-init data
	cloudInitData := cloudinit.GetCloudInitNoCloudSource(vmi)
	if cloudInitData != nil {
		hostname := vmi.Name
		if vmi.Spec.Hostname != "" {
			hostname = vmi.Spec.Hostname
		}
		hostname := dns.SanitizeHostname(vmi)

		err := cloudinit.GenerateLocalData(vmi.Name, hostname, vmi.Namespace, cloudInitData)
		if err != nil {

tests/utils.go

@@ -62,6 +62,7 @@ import (
	"kubevirt.io/kubevirt/pkg/controller"
	"kubevirt.io/kubevirt/pkg/kubecli"
	"kubevirt.io/kubevirt/pkg/log"
	"kubevirt.io/kubevirt/pkg/util/net/dns"
	"kubevirt.io/kubevirt/pkg/virt-controller/services"
	"kubevirt.io/kubevirt/pkg/virtctl"
)
@@ -1184,10 +1185,7 @@ func LoggedInCirrosExpecter(vmi *v1.VirtualMachineInstance) (expect.Expecter, er
	if err != nil {
		return nil, err
	}
	vmiName := vmi.Name
	if vmi.Spec.Hostname != "" {
		vmiName = vmi.Spec.Hostname
	}
	hostName := dns.SanitizeHostname(vmi)

	// Do not login, if we already logged in
	err = expecter.Send("\n")
@@ -1205,7 +1203,7 @@ func LoggedInCirrosExpecter(vmi *v1.VirtualMachineInstance) (expect.Expecter, er
		&expect.BSnd{S: "\n"},
		&expect.BExp{R: "login as 'cirros' user. default password: 'gocubsgo'. use 'sudo' for root."},
		&expect.BSnd{S: "\n"},
		&expect.BExp{R: vmiName + " login:"},
		&expect.BExp{R: hostName + " login:"},
		&expect.BSnd{S: "cirros\n"},
		&expect.BExp{R: "Password:"},
		&expect.BSnd{S: "gocubsgo\n"},