changing to IP_VERSIONS

Signed-off-by: Tyler Lloyd <Tyler.Lloyd@microsoft.com>

cmd/goldpinger/main.go

@@ -15,6 +15,7 @@
 package main
 
 import (
+	"k8s.io/utils/net"
 	"os"
 	"strconv"
 
@@ -132,6 +133,16 @@ func main() {
 	if goldpinger.GoldpingerConfig.PingNumber == 0 {
 		logger.Info("--ping-number set to 0: pinging all pods")
 	}
+	if goldpinger.GoldpingerConfig.IPVersions == nil || len(goldpinger.GoldpingerConfig.IPVersions) == 0 {
+		logger.Info("IPVersions not set: settings to 4 (IPv4)")
+		goldpinger.GoldpingerConfig.IPVersions = []string{"4"}
+	}
+	if len(goldpinger.GoldpingerConfig.IPVersions) > 1 {
+		logger.Warn("Multiple IP versions not supported. Will use first version specified as default", zap.Strings("IPVersions", goldpinger.GoldpingerConfig.IPVersions))
+	}
+	if goldpinger.GoldpingerConfig.IPVersions[0] != string(net.IPv4) && goldpinger.GoldpingerConfig.IPVersions[0] != net.IPv6 {
+		logger.Error("Unknown IP version specified: expected values are 4 or 6", zap.Strings("IPVersions", goldpinger.GoldpingerConfig.IPVersions))
+	}
 
 	server.ConfigureAPI()
 	goldpinger.StartUpdater()

pkg/goldpinger/config.go

@@ -30,13 +30,14 @@ var GoldpingerConfig = struct {
 	PingNumber       uint    `long:"ping-number" description:"Number of peers to ping. A value of 0 indicates all peers should be pinged." default:"0" env:"PING_NUMBER"`
 	Port             int     `long:"client-port-override" description:"(for testing) use this port when calling other instances" env:"CLIENT_PORT_OVERRIDE"`
 	UseHostIP        bool    `long:"use-host-ip" description:"When making the calls, use host ip (defaults to pod ip)" env:"USE_HOST_IP"`
-	UseIPv6          bool    `long:"use-ipv6" description:"Will find the IPv6 address on a pod to use for pinging." env:"USE_IPV6"`
 	LabelSelector    string  `long:"label-selector" description:"label selector to use to discover goldpinger pods in the cluster" env:"LABEL_SELECTOR" default:"app=goldpinger"`
 	Namespace        *string `long:"namespace" description:"namespace to use to discover goldpinger pods in the cluster (empty for all). Defaults to discovering the namespace for the current pod" env:"NAMESPACE"`
 	KubernetesClient *kubernetes.Clientset
 
 	DnsHosts []string `long:"host-to-resolve" description:"A host to attempt dns resolve on (space delimited)" env:"HOSTS_TO_RESOLVE" env-delim:" "`
 
+	IPVersions []string `long:"ip-versions" description:"The IP versions to use (space delimited). Possible values are 4 and 6 (defaults to 4)." env:"IP_VERSIONS" env-delim:" "`
+
 	// Timeouts
 	PingTimeoutMs     int64 `long:"ping-timeout-ms" description:"The timeout in milliseconds for a ping call to other goldpinger pods" env:"PING_TIMEOUT_MS" default:"300"`
 	CheckTimeoutMs    int64 `long:"check-timeout-ms" description:"The timeout in milliseconds for a check call to other goldpinger pods" env:"CHECK_TIMEOUT_MS" default:"1000"`

pkg/goldpinger/k8s.go

@@ -48,7 +48,7 @@ func getPodNamespace() string {
 // getHostIP gets the IP of the host where the pod is scheduled. If UseIPv6 is enabled then we need to check
 // the node IPs since HostIP will only list the default IP version one.
 func getHostIP(p v1.Pod) string {
-	if !GoldpingerConfig.UseIPv6 || k8snet.IsIPv6String(p.Status.HostIP) {
+	if ipMatchesConfig(p.Status.HostIP) {
 		return p.Status.HostIP
 	}
 
@@ -66,31 +66,31 @@ func getHostIP(p v1.Pod) string {
 		timer.ObserveDuration()
 	}
 
-	result := p.Status.HostIP
+	var hostIP string
 	for _, addr := range node.Status.Addresses {
-		if k8snet.IsIPv6String(addr.Address) {
-			result = addr.Address
+		if ipMatchesConfig(addr.Address) {
+			hostIP = addr.Address
 		}
 	}
-	nodeIPMap[p.Spec.NodeName] = result
-	return result
+	nodeIPMap[p.Spec.NodeName] = hostIP
+	return hostIP
 }
 
 // getPodIP will get an IPv6 IP from PodIPs if the UseIPv6 config is set, otherwise just return the object PodIP
 func getPodIP(p v1.Pod) string {
-	if !GoldpingerConfig.UseIPv6 {
+	if ipMatchesConfig(p.Status.PodIP) {
 		return p.Status.PodIP
 	}
 
-	var v6IP string
+	var podIP string
 	if p.Status.PodIPs != nil {
 		for _, ip := range p.Status.PodIPs {
-			if k8snet.IsIPv6String(ip.IP) {
-				v6IP = ip.IP
+			if ipMatchesConfig(ip.IP) {
+				podIP = ip.IP
 			}
 		}
 	}
-	return v6IP
+	return podIP
 }
 
 // GetAllPods returns a mapping from a pod name to a pointer to a GoldpingerPod(s)
@@ -114,3 +114,23 @@ func GetAllPods() map[string]*GoldpingerPod {
 	}
 	return podMap
 }
+
+// ipMatchesConfig checks if the input IP family matches the first entry in the IPVersions config.
+// TODO update to check all config versions to support dual-stack pinging.
+func ipMatchesConfig(ip string) bool {
+	ipFamily := getIPFamily(ip)
+	return GoldpingerConfig.IPVersions[0] == ipFamily
+}
+
+// getIPFamily returns the IP family of the input IP.
+// Possible values are 4 and 6.
+func getIPFamily(ip string) string {
+	if k8snet.IsIPv4String(ip) {
+		return string(k8snet.IPv4)
+	}
+	if k8snet.IsIPv6String(ip) {
+		return k8snet.IPv6
+	}
+	zap.L().Error("Error determining IP family", zap.String("IP", ip))
+	return ""
+}