Check for pod command Arg in pod CIDR discovery

...in addition to the command itself

Fixes #3180

Signed-off-by: Tom Pantelis <tompantelis@gmail.com>

pkg/discovery/network/generic_test.go

@@ -133,6 +133,20 @@ var _ = Describe("Generic Network", func() {
 		})
 	})
 
+	When("There is a kube-controller pod with the right parameter passed as an Arg", func() {
+		BeforeEach(func(ctx SpecContext) {
+			clusterNet = testDiscoverGenericWith(
+				ctx,
+				fakePodWithArg("kube-controller-manager", []string{"kube-controller-manager"}, "--cluster-cidr="+testPodCIDR),
+			)
+			Expect(clusterNet).NotTo(BeNil())
+		})
+
+		It("Should return the ClusterNetwork structure with pod CIDR", func() {
+			Expect(clusterNet.PodCIDRs).To(Equal([]string{testPodCIDR}))
+		})
+	})
+
 	When("There is a kube-proxy pod but no kube-controller", func() {
 		BeforeEach(func(ctx SpecContext) {
 			clusterNet = testDiscoverGenericWith(

pkg/discovery/network/network_suite_test.go

@@ -46,6 +46,13 @@ func fakePod(component string, command []string, env []v1.EnvVar) *v1.Pod {
 	return fakePodWithName(component, component, command, env)
 }
 
+func fakePodWithArg(component string, command []string, arg string, env ...v1.EnvVar) *v1.Pod {
+	pod := fakePodWithName(component, component, command, env)
+	pod.Spec.Containers[0].Args = []string{arg}
+
+	return pod
+}
+
 func fakePodWithName(name, component string, command []string, env []v1.EnvVar) *v1.Pod {
 	return fakePodWithNamespace("default", name, component, command, env)
 }

pkg/discovery/network/pods.go

@@ -20,6 +20,7 @@ package network
 
 import (
 	"context"
+	"slices"
 	"strings"
 
 	"github.com/pkg/errors"
@@ -39,7 +40,12 @@ func FindPodCommandParameter(ctx context.Context, client controllerClient.Client
 		for _, arg := range pod.Spec.Containers[i].Command {
 			if strings.HasPrefix(arg, parameter) {
 				return strings.SplitN(arg, "=", 2)[1], nil
+			} else if index := slices.IndexFunc(pod.Spec.Containers[i].Args, func(s string) bool {
+				return strings.HasPrefix(s, parameter)
+			}); index >= 0 {
+				return strings.SplitN(pod.Spec.Containers[i].Args[index], "=", 2)[1], nil
 			}
+
 			// Handling the case where the command is in the form of /bin/sh -c exec ....
 			if strings.Contains(arg, " ") {
 				for _, subArg := range strings.Split(arg, " ") {