hotunplug, unpluggedPodNic: implement reverse phase1

The commit includes removal of bridge, tap and dummy nic if they exist.
Follow up commits will take care of the caches files deletion.

Notice:
1. The cleanup is general and not binding specific. Any link created
by whatecer binding should be removed (although we curretnly support only
bridge binding hotunplug).
2. Error removing one of the links doesn't block removal on the others.

Signed-off-by: Alona Paz <alkaplan@redhat.com>

pkg/network/driver/common.go

@@ -71,6 +71,7 @@ type NetworkHandler interface {
 	LinkSetUp(link netlink.Link) error
 	LinkSetName(link netlink.Link, name string) error
 	LinkAdd(link netlink.Link) error
+	LinkDel(link netlink.Link) error
 	LinkSetLearningOff(link netlink.Link) error
 	ParseAddr(s string) (*netlink.Addr, error)
 	LinkSetHardwareAddr(link netlink.Link, hwaddr net.HardwareAddr) error
@@ -127,6 +128,9 @@ func (h *NetworkUtilsHandler) LinkSetName(link netlink.Link, name string) error
 func (h *NetworkUtilsHandler) LinkAdd(link netlink.Link) error {
 	return netlink.LinkAdd(link)
 }
+func (h *NetworkUtilsHandler) LinkDel(link netlink.Link) error {
+	return netlink.LinkDel(link)
+}
 func (h *NetworkUtilsHandler) LinkSetLearningOff(link netlink.Link) error {
 	return netlink.LinkSetLearning(link, false)
 }

pkg/network/driver/generated_mock_common.go

@@ -149,6 +149,16 @@ func (_mr *_MockNetworkHandlerRecorder) LinkAdd(arg0 interface{}) *gomock.Call {
 	return _mr.mock.ctrl.RecordCall(_mr.mock, "LinkAdd", arg0)
 }
 
+func (_m *MockNetworkHandler) LinkDel(link netlink.Link) error {
+	ret := _m.ctrl.Call(_m, "LinkDel", link)
+	ret0, _ := ret[0].(error)
+	return ret0
+}
+
+func (_mr *_MockNetworkHandlerRecorder) LinkDel(arg0 interface{}) *gomock.Call {
+	return _mr.mock.ctrl.RecordCall(_mr.mock, "LinkDel", arg0)
+}
+
 func (_m *MockNetworkHandler) LinkSetLearningOff(link netlink.Link) error {
 	ret := _m.ctrl.Call(_m, "LinkSetLearningOff", link)
 	ret0, _ := ret[0].(error)

pkg/network/setup/BUILD.bazel

@@ -9,6 +9,7 @@ go_library(
         "netstat.go",
         "network.go",
         "podnic.go",
+        "unpluggedpodnic.go",
     ],
     importpath = "kubevirt.io/kubevirt/pkg/network/setup",
     visibility = ["//visibility:public"],
@@ -29,6 +30,7 @@ go_library(
         "//staging/src/kubevirt.io/client-go/log:go_default_library",
         "//staging/src/kubevirt.io/client-go/precond:go_default_library",
         "//vendor/github.com/pkg/errors:go_default_library",
+        "//vendor/github.com/vishvananda/netlink:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/types:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/util/errors:go_default_library",
     ],
@@ -44,6 +46,7 @@ go_test(
         "network_suite_test.go",
         "network_test.go",
         "podnic_test.go",
+        "unpluggedpodnic_test.go",
     ],
     embed = [":go_default_library"],
     deps = [

pkg/network/setup/network.go

@@ -126,9 +126,8 @@ func (n *VMNetworkConfigurator) UnplugPodNetworksPhase1(vmi *v1.VirtualMachineIn
 	err := configState.UnplugNetworks(
 		vmi,
 		func(network string) error {
-			// TODO clean cache
-			// TODO remove bridge and tap device
-			return nil
+			unpluggedPodNic := NewUnpluggedpodnic(network, n.handler)
+			return unpluggedPodNic.UnplugPhase1()
 		})
 	if err != nil {
 		return fmt.Errorf("failed unplug pod networks phase1: %w", err)

pkg/network/setup/unpluggedpodnic.go

@@ -0,0 +1,73 @@
+package network
+
+import (
+	"errors"
+
+	v1 "kubevirt.io/api/core/v1"
+
+	"kubevirt.io/kubevirt/pkg/network/namescheme"
+
+	"github.com/vishvananda/netlink"
+	k8serrors "k8s.io/apimachinery/pkg/util/errors"
+
+	netdriver "kubevirt.io/kubevirt/pkg/network/driver"
+	virtnetlink "kubevirt.io/kubevirt/pkg/network/link"
+)
+
+type Unpluggedpodnic struct {
+	networkName string
+	handler     netdriver.NetworkHandler
+}
+
+func NewUnpluggedpodnic(network string, handler netdriver.NetworkHandler) Unpluggedpodnic {
+	return Unpluggedpodnic{networkName: network, handler: handler}
+}
+
+func (c Unpluggedpodnic) UnplugPhase1() error {
+	var unplugErrors []error
+
+	dummyNet := v1.Network{
+		Name: c.networkName,
+		NetworkSource: v1.NetworkSource{
+			Multus: &v1.MultusNetwork{},
+		},
+	} // TODO - remove this dummy network once we will have the absent network object
+	podInterfaceName := namescheme.HashedPodInterfaceName(dummyNet)
+	bridgeName := virtnetlink.GenerateBridgeName(podInterfaceName)
+	err := c.delLinkIfExists(bridgeName)
+	if err != nil {
+		unplugErrors = append(unplugErrors, err)
+	}
+
+	// remove extra nic
+	dummyIfaceName := virtnetlink.GenerateNewBridgedVmiInterfaceName(podInterfaceName)
+	err = c.delLinkIfExists(dummyIfaceName)
+	if err != nil {
+		unplugErrors = append(unplugErrors, err)
+	}
+
+	// remove tap if exists
+	tapDeviceName := virtnetlink.GenerateTapDeviceName(podInterfaceName)
+	err = c.delLinkIfExists(tapDeviceName)
+	if err != nil {
+		unplugErrors = append(unplugErrors, err)
+	}
+
+	// clean caches
+	// TODO remove all three cache files
+
+	return k8serrors.NewAggregate(unplugErrors)
+
+}
+
+func (c Unpluggedpodnic) delLinkIfExists(linkName string) error {
+	link, err := c.handler.LinkByName(linkName)
+	if err != nil {
+		var linkNotFoundErr netlink.LinkNotFoundError
+		if errors.As(err, &linkNotFoundErr) {
+			return nil
+		}
+		return err
+	}
+	return c.handler.LinkDel(link)
+}

pkg/network/setup/unpluggedpodnic_test.go

@@ -0,0 +1,99 @@
+/*
+* 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 2023 Red Hat, Inc.
+*
+ */
+
+package network_test
+
+import (
+	"fmt"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+
+	"github.com/golang/mock/gomock"
+
+	"github.com/vishvananda/netlink"
+
+	netdriver "kubevirt.io/kubevirt/pkg/network/driver"
+	network "kubevirt.io/kubevirt/pkg/network/setup"
+)
+
+var _ = Describe("Unpluggedpodnic", func() {
+	var (
+		mockHandler     *netdriver.MockNetworkHandler
+		ctrl            *gomock.Controller
+		unpluggedpodnic network.Unpluggedpodnic
+		tapLink         *netlink.GenericLink
+		dummyIfaceLink  *netlink.GenericLink
+		bridgeLink      *netlink.GenericLink
+	)
+	const (
+		tapName        = "tap16477688c0e"
+		dummyIfaceName = "16477688c0e-nic"
+		bridgeName     = "k6t-16477688c0e"
+		networkName    = "blue"
+	)
+
+	BeforeEach(func() {
+		ctrl = gomock.NewController(GinkgoT())
+		mockHandler = netdriver.NewMockNetworkHandler(ctrl)
+
+		unpluggedpodnic = network.NewUnpluggedpodnic(networkName, mockHandler)
+
+		tapLink = &netlink.GenericLink{}
+		dummyIfaceLink = &netlink.GenericLink{}
+		bridgeLink = &netlink.GenericLink{}
+	})
+
+	Context("UnplugPhase1", func() {
+		It("successfully when bridge, tap and dummy nic exist", func() {
+			mockHandler.EXPECT().LinkByName(tapName).Return(tapLink, nil)
+			mockHandler.EXPECT().LinkByName(dummyIfaceName).Return(dummyIfaceLink, nil)
+			mockHandler.EXPECT().LinkByName(bridgeName).Return(bridgeLink, nil)
+			mockHandler.EXPECT().LinkDel(tapLink).Return(nil)
+			mockHandler.EXPECT().LinkDel(dummyIfaceLink).Return(nil)
+			mockHandler.EXPECT().LinkDel(bridgeLink).Return(nil)
+
+			Expect(unpluggedpodnic.UnplugPhase1()).To(Succeed())
+		})
+		It("successfully when dummy nic doesn't exist", func() {
+			mockHandler.EXPECT().LinkByName(tapName).Return(tapLink, nil)
+			mockHandler.EXPECT().LinkByName(dummyIfaceName).Return(nil, netlink.LinkNotFoundError{})
+			mockHandler.EXPECT().LinkByName(bridgeName).Return(bridgeLink, nil)
+			mockHandler.EXPECT().LinkDel(tapLink).Return(nil)
+			mockHandler.EXPECT().LinkDel(bridgeLink).Return(nil)
+
+			Expect(unpluggedpodnic.UnplugPhase1()).To(Succeed())
+		})
+		It("partially fails when some of the devices fail to be removed", func() {
+			const (
+				linkByNameErr1 = "link by name error1"
+				linkByNameErr2 = "link by name error2"
+			)
+
+			mockHandler.EXPECT().LinkByName(tapName).Return(tapLink, nil)
+			mockHandler.EXPECT().LinkByName(dummyIfaceName).Return(nil, fmt.Errorf(linkByNameErr1))
+			mockHandler.EXPECT().LinkByName(bridgeName).Return(bridgeLink, fmt.Errorf(linkByNameErr2))
+			mockHandler.EXPECT().LinkDel(tapLink).Return(nil)
+
+			err := unpluggedpodnic.UnplugPhase1()
+			Expect(err.Error()).To(ContainSubstring(linkByNameErr1))
+			Expect(err.Error()).To(ContainSubstring(linkByNameErr1))
+		})
+	})
+})