connectivity: fix service propagation check with mismatching IP families

0dccab2 ("connectivity: wait for service propagation in agents")
introduced an additional check to wait until all test services have been
synchronized by cilium agents before starting the actual tests. Yet,
this check will never succeed if the cluster is configured in dual stack
mode, but only one IP family is enabled by Cilium. Indeed, the backends
for the disabled IP family will never be populated. Hence, let's skip
this check if the ClusterIP belongs to a disabled IP family.

Fixes: 0dccab2 ("connectivity: wait for service propagation in agents")
Reported-by: Donia Chaiehloudj <[email protected]>
Signed-off-by: Marco Iorio <[email protected]>

connectivity/check/deployment.go

@@ -1269,7 +1269,7 @@ func (ct *ConnectivityTest) validateDeployment(ctx context.Context) error {
 
 		for _, agent := range ct.CiliumPods() {
 			if _, ok := nodes[agent.NodeName()]; ok {
-				if err := WaitForServiceEndpoints(ctx, ct, agent, s, 1); err != nil {
+				if err := WaitForServiceEndpoints(ctx, ct, agent, s, 1, ct.Features.IPFamilies()); err != nil {
 					return err
 				}
 			}

connectivity/check/features.go

@@ -111,6 +111,21 @@ func (fs FeatureSet) MatchRequirements(reqs ...FeatureRequirement) bool {
 	return true
 }
 
+// IPFamilies returns the list of enabled IP families.
+func (fs FeatureSet) IPFamilies() []IPFamily {
+	var families []IPFamily
+
+	if fs.MatchRequirements(RequireFeatureEnabled(FeatureIPv4)) {
+		families = append(families, IPFamilyV4)
+	}
+
+	if fs.MatchRequirements(RequireFeatureEnabled(FeatureIPv6)) {
+		families = append(families, IPFamilyV6)
+	}
+
+	return families
+}
+
 // deriveFeatures derives additional features based on the status of other features
 func (fs FeatureSet) deriveFeatures() error {
 	fs[FeatureHostPort] = FeatureStatus{

connectivity/check/wait.go

@@ -8,11 +8,13 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"net/netip"
 	"strconv"
 	"strings"
 	"time"
 
 	"github.com/cilium/cilium/api/v1/models"
+	"golang.org/x/exp/slices"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 
 	"github.com/cilium/cilium-cli/defaults"
@@ -171,15 +173,15 @@ func WaitForService(ctx context.Context, log Logger, client Pod, service Service
 
 // WaitForServiceEndpoints waits until the expected number of service backends
 // are reported by the given agent.
-func WaitForServiceEndpoints(ctx context.Context, log Logger, agent Pod, service Service, backends uint) error {
+func WaitForServiceEndpoints(ctx context.Context, log Logger, agent Pod, service Service, backends uint, families []IPFamily) error {
 	log.Logf("⌛ [%s] Waiting for Service %s to be synchronized by Cilium pod %s",
 		agent.K8sClient.ClusterName(), service.Name(), agent.Name())
 
 	ctx, cancel := context.WithTimeout(ctx, ShortTimeout)
 	defer cancel()
 
 	for {
-		err := checkServiceEndpoints(ctx, agent, service, backends)
+		err := checkServiceEndpoints(ctx, agent, service, backends, families)
 		if err == nil {
 			return nil
 		}
@@ -196,7 +198,7 @@ func WaitForServiceEndpoints(ctx context.Context, log Logger, agent Pod, service
 	}
 }
 
-func checkServiceEndpoints(ctx context.Context, agent Pod, service Service, backends uint) error {
+func checkServiceEndpoints(ctx context.Context, agent Pod, service Service, backends uint, families []IPFamily) error {
 	buffer, err := agent.K8sClient.ExecInPod(ctx, agent.Namespace(), agent.NameWithoutNamespace(),
 		defaults.AgentContainerName, []string{"cilium", "service", "list", "--output=json"})
 	if err != nil {
@@ -222,6 +224,17 @@ func checkServiceEndpoints(ctx context.Context, agent Pod, service Service, back
 	}
 
 	for _, ip := range service.Service.Spec.ClusterIPs {
+		addr, err := netip.ParseAddr(ip)
+		if err != nil {
+			return fmt.Errorf("failed to parse ClusterIP %q: %w", ip, err)
+		}
+
+		// Skip the check for a given address if the corresponding IP family is not
+		// enabled in Cilium, as the backends will never be populated.
+		if addr.Is4() && !slices.Contains(families, IPFamilyV4) || addr.Is6() && !slices.Contains(families, IPFamilyV6) {
+			continue
+		}
+
 		for _, port := range service.Service.Spec.Ports {
 			if found[l3n4{addr: ip, port: uint16(port.Port)}] < backends {
 				return errors.New("service not yet synchronized")