Binary for mtu and veth prefix check

test/agent/Dockerfile

@@ -26,6 +26,9 @@ RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 GO111MODULE=on go build \
 RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 GO111MODULE=on go build \
     -a -o metric-server cmd/metric-server/main.go
 
+RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 GO111MODULE=on go build \
+    -a -o aws-node-config cmd/aws-node-config/main.go
+
 FROM public.ecr.aws/amazonlinux/amazonlinux:2
 RUN yum update -y && \
     yum clean all

test/agent/cmd/aws-node-config/main.go

@@ -0,0 +1,156 @@
+// Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"). You may
+// not use this file except in compliance with the License. A copy of the
+// License is located at
+//
+//     http://aws.amazon.com/apache2.0/
+//
+// or in the "license" file accompanying this file. This file 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.
+package main
+
+import (
+	"crypto/sha1"
+	"encoding/base64"
+	"encoding/hex"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"log"
+	"net"
+	"strings"
+
+	"github.com/aws/amazon-vpc-cni-k8s/test/agent/pkg/input"
+)
+
+const (
+	MTU_CHECK         = "mtu"
+	VETH_PREFIX_CHECK = "veth"
+)
+
+type MTU_CONFIG struct {
+	ExpectedVal int
+}
+
+func main() {
+	validate := ""
+	config := ""
+
+	flag.StringVar(&validate, "validate", "", "name of the test, valid values: mtu, veth")
+	flag.StringVar(&config, "config", "", "Base64 encoded json object for the given test")
+	flag.Parse()
+
+	decoded, err := base64.StdEncoding.DecodeString(config)
+	if err != nil {
+		log.Fatalf("failed to descode base64 string %s: %v", config, err)
+	}
+
+	switch validate {
+	case MTU_CHECK:
+		validateMTUValue(decoded)
+	case VETH_PREFIX_CHECK:
+		validateVethPairCount(decoded)
+	default:
+		fmt.Println("Invalid test-name choice")
+	}
+}
+
+func validateVethPairCount(config []byte) {
+	var podNetworkingValidationInput input.PodNetworkingValidationInput
+	err := json.Unmarshal(config, &podNetworkingValidationInput)
+	if err != nil {
+		log.Fatalf("failed to unmarshall json string %s: %v", config, err)
+	}
+
+	log.Printf("podNetworkingValidationInput: %+v\n", podNetworkingValidationInput)
+
+	if podNetworkingValidationInput.VethPrefix == "" {
+		podNetworkingValidationInput.VethPrefix = "eni"
+	}
+
+	actual := 0
+	vethPairs := make(map[string]bool, len(podNetworkingValidationInput.PodList))
+
+	for _, pod := range podNetworkingValidationInput.PodList {
+		// Get the veth pair for pod in host network namespace
+		hostVethName := getHostVethPairName(pod, podNetworkingValidationInput.VethPrefix)
+		log.Printf("hostVethName: %v\n", hostVethName)
+		vethPairs[hostVethName] = false
+	}
+
+	interfaces, err := net.Interfaces()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	for _, ni := range interfaces {
+		if checked, ok := vethPairs[ni.Name]; ok {
+			if !checked {
+				actual++
+			}
+		}
+	}
+
+	if actual == len(podNetworkingValidationInput.PodList) {
+		log.Println("Veth Check: Passed")
+	} else {
+		log.Println("Veth Check: Failed")
+		log.Println("Missing Veth pairs")
+		for name, val := range vethPairs {
+			if !val {
+				log.Println(name)
+			}
+		}
+	}
+}
+
+func validateMTUValue(config []byte) {
+	mtuConfig := MTU_CONFIG{}
+	err := json.Unmarshal(config, &mtuConfig)
+
+	if err != nil {
+		log.Fatalf("failed to unmarshall json string %s: %v", config, err)
+	}
+
+	log.Printf("MTU_CONFIG: %+v\n", mtuConfig)
+
+	if mtuConfig.ExpectedVal == 0 {
+		mtuConfig.ExpectedVal = 9001
+	}
+
+	interfaces, err := net.Interfaces()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	ok := false
+	failedInterfaces := make([]string, 0)
+	for _, ni := range interfaces {
+		if strings.HasPrefix(ni.Name, "eth") {
+			if ni.MTU != mtuConfig.ExpectedVal {
+				failedInterfaces = append(failedInterfaces, ni.Name)
+			}
+			ok = true
+		}
+	}
+	if !ok {
+		log.Println("MTU Check: Failed")
+		log.Println("Could not find eth interface, check ifconfig on the node")
+	} else {
+		if len(failedInterfaces) != 0 {
+			log.Println("MTU Check: Failed")
+			log.Printf("Failed Interfaces: %+v\n", failedInterfaces)
+		} else {
+			log.Println("MTU Check: Passed")
+		}
+	}
+}
+
+func getHostVethPairName(input input.Pod, vethPrefix string) string {
+	h := sha1.New()
+	h.Write([]byte(fmt.Sprintf("%s.%s", input.PodNamespace, input.PodName)))
+	return fmt.Sprintf("%s%s", vethPrefix, hex.EncodeToString(h.Sum(nil))[:11])
+}