Binary for mtu and veth prefix check

test/agent/cmd/networking/tester/network.go

@@ -69,6 +69,16 @@ func TestNetworkingSetupForRegularPod(podNetworkingValidationInput input.PodNetw
 			continue
 		}
 
+		// Validate MTU value if it is set to true
+		if podNetworkingValidationInput.ValidateMTU {
+			if link.Attrs().MTU != podNetworkingValidationInput.MTU {
+				validationErrors = append(validationErrors,
+					fmt.Errorf("MTU value %v for pod: %s on veth pair: %s failed to match the expected value: %v", link.Attrs().MTU, pod.PodName, hostVethName, podNetworkingValidationInput.MTU))
+			} else {
+				log.Printf("Found Valid MTU value:%d for pod: %s on veth Pair: %s\n", link.Attrs().MTU, pod.PodName, hostVethName)
+			}
+		}
+
 		// Verify IP Link for the Pod is UP
 		isLinkUp := strings.Contains(link.Attrs().Flags.String(), "up")
 		if !isLinkUp {

test/agent/pkg/input/input.go

@@ -13,6 +13,8 @@
 
 package input
 
+import "encoding/json"
+
 type TestStatus struct {
 	SuccessCount int
 	FailureCount int
@@ -32,6 +34,10 @@ type PodNetworkingValidationInput struct {
 	VethPrefix string
 	// List of pod to validate the networking
 	PodList []Pod
+	// Should Validate MTU value, by default it will false
+	ValidateMTU bool
+	// Expected MTU value
+	MTU int
 }
 
 type Pod struct {
@@ -45,3 +51,11 @@ type Pod struct {
 	// from the Secondary ENI
 	IsIPFromSecondaryENI bool
 }
+
+func (ip PodNetworkingValidationInput) Serialize() (string, error) {
+	inputBytes, err := json.Marshal(ip)
+	if err != nil {
+		return "", err
+	}
+	return string(inputBytes), nil
+}

test/framework/utils/utils.go

@@ -14,6 +14,7 @@
 package utils
 
 import (
+	appsV1 "k8s.io/api/apps/v1"
 	v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/types"
 )
@@ -25,3 +26,13 @@ func NamespacedName(obj v1.Object) types.NamespacedName {
 		Name:      obj.GetName(),
 	}
 }
+
+func GetEnvValueForKeyFromDaemonSet(key string, ds *appsV1.DaemonSet) string {
+	envVar := ds.Spec.Template.Spec.Containers[0].Env
+	for _, env := range envVar {
+		if env.Name == key {
+			return env.Value
+		}
+	}
+	return ""
+}

test/integration-new/cni/host_networking_test.go

@@ -14,14 +14,15 @@
 package cni
 
 import (
-	"encoding/json"
 	"fmt"
+	"strconv"
 	"time"
 
 	"github.com/aws/amazon-vpc-cni-k8s/test/agent/pkg/input"
 	v1 "k8s.io/api/core/v1"
 
 	"github.com/aws/amazon-vpc-cni-k8s/test/framework/resources/k8s/manifest"
+	k8sUtils "github.com/aws/amazon-vpc-cni-k8s/test/framework/resources/k8s/utils"
 	"github.com/aws/amazon-vpc-cni-k8s/test/framework/utils"
 
 	. "github.com/onsi/ginkgo"
@@ -39,6 +40,13 @@ const (
 	NetworkingSetupFails
 )
 
+const (
+	AWS_VPC_ENI_MTU            = "AWS_VPC_ENI_MTU"
+	AWS_VPC_K8S_CNI_VETHPREFIX = "AWS_VPC_K8S_CNI_VETHPREFIX"
+	NEW_MTU_VAL                = 1300
+	NEW_VETH_PREFIX            = "veth"
+)
+
 var _ = Describe("test host networking", func() {
 	var err error
 	var podLabelKey = "app"
@@ -71,7 +79,8 @@ var _ = Describe("test host networking", func() {
 				Should(BeNumerically(">", 0))
 
 			By("generating the pod networking validation input to be passed to tester")
-			input := GetPodNetworkingValidationInput(interfaceTypeToPodList)
+			input, err := GetPodNetworkingValidationInput(interfaceTypeToPodList).Serialize()
+			Expect(err).NotTo(HaveOccurred())
 
 			By("validating host networking setup is setup correctly")
 			ValidateHostNetworking(NetworkingSetupSucceeds, input)
@@ -87,6 +96,64 @@ var _ = Describe("test host networking", func() {
 			By("validating host networking is teared down correctly")
 			ValidateHostNetworking(NetworkingTearDownSucceeds, input)
 		})
+
+		It("Validate Host Networking setup after changing MTU and Veth Prefix", func() {
+			deployment := manifest.NewBusyBoxDeploymentBuilder().
+				Replicas(6).
+				PodLabel(podLabelKey, podLabelVal).
+				NodeName(primaryNode.Name).
+				Build()
+
+			By("Configuring Veth Prefix and MTU value on aws-node daemonset")
+			ds, err := f.K8sResourceManagers.DaemonSetManager().GetDaemonSet(utils.AwsNodeNamespace, utils.AwsNodeName)
+			Expect(err).NotTo(HaveOccurred())
+
+			oldMTU := utils.GetEnvValueForKeyFromDaemonSet(AWS_VPC_ENI_MTU, ds)
+			oldVethPrefix := utils.GetEnvValueForKeyFromDaemonSet(AWS_VPC_K8S_CNI_VETHPREFIX, ds)
+
+			k8sUtils.AddEnvVarToDaemonSetAndWaitTillUpdated(f, utils.AwsNodeName, utils.AwsNodeNamespace, utils.AwsNodeName, map[string]string{
+				AWS_VPC_ENI_MTU:            strconv.Itoa(NEW_MTU_VAL),
+				AWS_VPC_K8S_CNI_VETHPREFIX: NEW_VETH_PREFIX,
+			})
+
+			By("creating a deployment to launch pods")
+			deployment, err = f.K8sResourceManagers.DeploymentManager().
+				CreateAndWaitTillDeploymentIsReady(deployment, utils.DefaultDeploymentReadyTimeout)
+			Expect(err).ToNot(HaveOccurred())
+
+			By("getting the list of pods using IP from primary and secondary ENI")
+			interfaceTypeToPodList :=
+				GetPodsOnPrimaryAndSecondaryInterface(primaryNode, podLabelKey, podLabelVal)
+
+			By("generating the pod networking validation input to be passed to tester")
+			podNetworkingValidationInput := GetPodNetworkingValidationInput(interfaceTypeToPodList)
+			podNetworkingValidationInput.VethPrefix = NEW_VETH_PREFIX
+			podNetworkingValidationInput.ValidateMTU = true
+			podNetworkingValidationInput.MTU = NEW_MTU_VAL
+			input, err := podNetworkingValidationInput.Serialize()
+			Expect(err).NotTo(HaveOccurred())
+
+			By("validating host networking setup is setup correctly with MTU check as well")
+			ValidateHostNetworking(NetworkingSetupSucceeds, input)
+
+			// Restore MTU and Veth Prefix
+			By("Restoring MTU value and Veth Prefix to old values")
+			k8sUtils.AddEnvVarToDaemonSetAndWaitTillUpdated(f, utils.AwsNodeName, utils.AwsNodeNamespace, utils.AwsNodeName, map[string]string{
+				AWS_VPC_ENI_MTU:            oldMTU,
+				AWS_VPC_K8S_CNI_VETHPREFIX: oldVethPrefix,
+			})
+
+			By("deleting the deployment to test teardown")
+			err = f.K8sResourceManagers.DeploymentManager().
+				DeleteAndWaitTillDeploymentIsDeleted(deployment)
+			Expect(err).ToNot(HaveOccurred())
+
+			By("waiting to allow CNI to tear down networking for terminated pods")
+			time.Sleep(time.Second * 60)
+
+			By("validating host networking is teared down correctly")
+			ValidateHostNetworking(NetworkingTearDownSucceeds, input)
+		})
 	})
 
 	Context("when host networking is tested on invalid input", func() {
@@ -103,9 +170,10 @@ var _ = Describe("test host networking", func() {
 				CreatAndWaitTillRunning(parkingPod)
 			Expect(err).ToNot(HaveOccurred())
 
-			validInput := GetPodNetworkingValidationInput(InterfaceTypeToPodList{
+			validInput, err := GetPodNetworkingValidationInput(InterfaceTypeToPodList{
 				PodsOnPrimaryENI: []v1.Pod{*parkingPod},
-			})
+			}).Serialize()
+			Expect(err).NotTo(HaveOccurred())
 
 			By("first validating the tester work on valid input")
 			ValidateHostNetworking(NetworkingSetupSucceeds, validInput)
@@ -114,19 +182,22 @@ var _ = Describe("test host networking", func() {
 			invalidPod := parkingPod.DeepCopy()
 			invalidPod.Status.PodIP = "1.1.1.1"
 
-			invalidInput := GetPodNetworkingValidationInput(InterfaceTypeToPodList{
+			invalidInput, err := GetPodNetworkingValidationInput(InterfaceTypeToPodList{
 				PodsOnPrimaryENI: []v1.Pod{*invalidPod},
-			})
+			}).Serialize()
+			Expect(err).NotTo(HaveOccurred())
+
 			ValidateHostNetworking(NetworkingSetupFails, invalidInput)
 
 			By("validating the tester fails when invalid namespace is passed")
 			invalidPod = parkingPod.DeepCopy()
 			// veth pair name is generated using namespace+name so the test should fail
 			invalidPod.Namespace = "different"
 
-			invalidInput = GetPodNetworkingValidationInput(InterfaceTypeToPodList{
+			invalidInput, err = GetPodNetworkingValidationInput(InterfaceTypeToPodList{
 				PodsOnPrimaryENI: []v1.Pod{*invalidPod},
-			})
+			}).Serialize()
+			Expect(err).NotTo(HaveOccurred())
 
 			ValidateHostNetworking(NetworkingSetupFails, invalidInput)
 
@@ -194,12 +265,13 @@ func ValidateHostNetworking(testType TestType, podValidationInputString string)
 
 // GetPodNetworkingValidationInput returns input string containing the list of pods for which
 // the host networking has to be tested
-func GetPodNetworkingValidationInput(interfaceTypeToPodList InterfaceTypeToPodList) string {
+func GetPodNetworkingValidationInput(interfaceTypeToPodList InterfaceTypeToPodList) input.PodNetworkingValidationInput {
 
 	ip := input.PodNetworkingValidationInput{
 		VPCCidrRange: vpcCIDRs,
 		VethPrefix:   "eni",
 		PodList:      []input.Pod{},
+		ValidateMTU:  false,
 	}
 
 	for _, primaryENIPod := range interfaceTypeToPodList.PodsOnPrimaryENI {
@@ -220,8 +292,5 @@ func GetPodNetworkingValidationInput(interfaceTypeToPodList InterfaceTypeToPodLi
 		})
 	}
 
-	inputBytes, err := json.Marshal(ip)
-	Expect(err).ToNot(HaveOccurred())
-
-	return string(inputBytes)
+	return ip
 }