creating a unit test using mocking for the generate SS function

Makefile

@@ -10,7 +10,10 @@ EXECUTABLE := commatrix-gen
 .DEFAULT_GOAL := run
 
 build:
-	go build -o $(EXECUTABLE) $(GO_SRC) 
+	go build -o $(EXECUTABLE) $(GO_SRC)
+
+mock-generate:
+	go generate ./...
 
 oc:
 ifeq (, $(shell which oc))

cmd/main.go

@@ -6,6 +6,10 @@ import (
 	"os"
 	"path/filepath"
 
+	"github.com/openshift-kni/commatrix/debug"
+
+	clientutil "github.com/openshift-kni/commatrix/client"
+
 	"github.com/openshift-kni/commatrix/commatrix"
 )
 
@@ -33,6 +37,10 @@ func main() {
 	if !ok {
 		panic("must set the KUBECONFIG environment variable")
 	}
+	cs, err := clientutil.New(kubeconfig)
+	if err != nil {
+		panic("must set the KUBECONFIG environment variable")
+	}
 
 	var env commatrix.Env
 	switch envStr {
@@ -68,7 +76,8 @@ func main() {
 		panic(fmt.Sprintf("Error while writing the endpoint slice matrix to file :%v", err))
 	}
 	// generate the ss matrix and ss raws
-	ssMat, ssOutTCP, ssOutUDP, err := commatrix.GenerateSS(kubeconfig, customEntriesPath, customEntriesFormat, format, env, deployment, destDir)
+	newDebugPod := &debug.NewDebugPod{}
+	ssMat, ssOutTCP, ssOutUDP, err := commatrix.GenerateSS(cs, newDebugPod)
 	if err != nil {
 		panic(fmt.Sprintf("Error while generating the ss matrix and ss raws :%v", err))
 	}

commatrix/commatrix_test.go

@@ -1,12 +1,23 @@
 package commatrix
 
 import (
+	"context"
 	"fmt"
 	"path/filepath"
+	"strings"
 	"testing"
+	"time"
+
+	gomock "go.uber.org/mock/gomock"
 
-	"github.com/openshift-kni/commatrix/types"
 	"github.com/stretchr/testify/assert"
+	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/client-go/kubernetes/fake"
+
+	clientutil "github.com/openshift-kni/commatrix/client"
+	"github.com/openshift-kni/commatrix/debug"
+	"github.com/openshift-kni/commatrix/types"
 )
 
 func TestGetPrintFunction(t *testing.T) {
@@ -50,3 +61,69 @@ func TestWriteMatrixToFile(t *testing.T) {
 	assert.NoError(t, err)
 	assert.FileExists(t, filepath.Join(destDir, "test-matrix.json"))
 }
+
+func TestGenerateSS(t *testing.T) {
+	fakeClientset := fake.NewSimpleClientset()
+	clientset := &clientutil.ClientSet{
+		CoreV1Interface: fakeClientset.CoreV1(),
+	}
+
+	ctrlTest := gomock.NewController(t)
+	defer ctrlTest.Finish()
+
+	mockDebugPod := debug.NewMockDebugPodInterface(ctrlTest)
+	NewmockDebugPod := debug.NewMockNewDebugPodInterface(ctrlTest)
+
+	tcpOutput := []byte(`LISTEN 0      4096      127.0.0.1:8797  0.0.0.0:* users:(("machine-config-",pid=3534,fd=3))                
+LISTEN 0      4096      127.0.0.1:8798  0.0.0.0:* users:(("machine-config-",pid=3534,fd=13))               
+LISTEN 0      4096      127.0.0.1:9100  0.0.0.0:* users:(("node_exporter",pid=4147,fd=3))`)
+
+	udpOutput := []byte(`UNCONN 0      0           0.0.0.0:111   0.0.0.0:* users:(("rpcbind",pid=1399,fd=5),("systemd",pid=1,fd=78))
+UNCONN 0      0         127.0.0.1:323   0.0.0.0:* users:(("chronyd",pid=1015,fd=5))                        
+UNCONN 0      0      10.46.97.104:500   0.0.0.0:* users:(("pluto",pid=2115,fd=21))`)
+	Output := []byte(`1: /system.slice/containerd.service
+	2: /system.slice/kubelet.service
+	3: /system.slice/sshd.service`)
+
+	// Set up the expectations
+	mockDebugPod.EXPECT().ExecWithRetry(gomock.Any(), gomock.Any(), gomock.Any()).DoAndReturn(
+		func(cmd string, interval, duration time.Duration) ([]byte, error) {
+			if strings.HasPrefix(cmd, "cat /proc/") && strings.Contains(cmd, "/cgroup") {
+				return Output, nil
+			}
+			if cmd == "ss -anpltH" {
+				return tcpOutput, nil
+			}
+			if cmd == "ss -anpluH" {
+				return udpOutput, nil
+			}
+			return nil, fmt.Errorf("unknown command")
+		},
+	).AnyTimes()
+
+	mockDebugPod.EXPECT().Clean().Return(nil).AnyTimes()
+	mockDebugPod.EXPECT().GetNodeName().Return("test-node").AnyTimes()
+
+	NewmockDebugPod.EXPECT().New(clientset, "test-node", "openshift-commatrix-debug", "quay.io/openshift-release-dev/ocp-release:4.15.12-multi").Return(mockDebugPod, nil)
+
+	testNode := &corev1.Node{
+		ObjectMeta: metav1.ObjectMeta{
+			Name: "test-node",
+		},
+	}
+	_, _ = clientset.CoreV1Interface.Nodes().Create(context.TODO(), testNode, metav1.CreateOptions{})
+
+	ssMat, ssOutTCP, ssOutUDP, err := GenerateSS(clientset, NewmockDebugPod)
+
+	// Pass the expected ClientSet to GenerateSS
+	expectedSSMat := &types.ComMatrix{
+		Matrix: []types.ComDetails{
+			{Direction: "Ingress", Protocol: "UDP", Port: 111, Namespace: "", Service: "rpcbind", Pod: "", Container: "", NodeRole: "", Optional: false},
+			{Direction: "Ingress", Protocol: "UDP", Port: 500, Namespace: "", Service: "pluto", Pod: "", Container: "", NodeRole: "", Optional: false},
+		}}
+
+	assert.NoError(t, err)
+	assert.Equal(t, expectedSSMat, ssMat, "Expected and actual ssMat values should match")
+	assert.Equal(t, "node: test-node\nLISTEN 0      4096      127.0.0.1:8797  0.0.0.0:* users:((\"machine-config-\",pid=3534,fd=3))                \nLISTEN 0      4096      127.0.0.1:8798  0.0.0.0:* users:((\"machine-config-\",pid=3534,fd=13))               \nLISTEN 0      4096      127.0.0.1:9100  0.0.0.0:* users:((\"node_exporter\",pid=4147,fd=3))\n", string(ssOutTCP))
+	assert.Equal(t, "node: test-node\nUNCONN 0      0           0.0.0.0:111   0.0.0.0:* users:((\"rpcbind\",pid=1399,fd=5),(\"systemd\",pid=1,fd=78))\nUNCONN 0      0         127.0.0.1:323   0.0.0.0:* users:((\"chronyd\",pid=1015,fd=5))                        \nUNCONN 0      0      10.46.97.104:500   0.0.0.0:* users:((\"pluto\",pid=2115,fd=21))\n", string(ssOutUDP))
+}

commatrix/generate.go

@@ -18,12 +18,7 @@ import (
 	"github.com/openshift-kni/commatrix/types"
 )
 
-func GenerateSS(kubeconfig, customEntriesPath, customEntriesFormat, format string, env Env, deployment Deployment, destDir string) (ssMat *types.ComMatrix, ssOutTCP, ssOutUDP []byte, err error) {
-	cs, err := clientutil.New(kubeconfig)
-	if err != nil {
-		return nil, nil, nil, err
-	}
-
+func GenerateSS(cs *clientutil.ClientSet, debugPod debug.NewDebugPodInterface) (ssMat *types.ComMatrix, ssOutTCP, ssOutUDP []byte, err error) {
 	nodesList, err := cs.CoreV1Interface.Nodes().List(context.TODO(), metav1.ListOptions{})
 	if err != nil {
 		return nil, nil, nil, err
@@ -46,18 +41,18 @@ func GenerateSS(kubeconfig, customEntriesPath, customEntriesFormat, format strin
 	for _, n := range nodesList.Items {
 		node := n
 		g.Go(func() error {
-			debugPod, err := debug.New(cs, node.Name, consts.DefaultDebugNamespace, consts.DefaultDebugPodImage)
+			newdebugPod, err := debugPod.New(cs, node.Name, consts.DefaultDebugNamespace, consts.DefaultDebugPodImage)
 			if err != nil {
 				return err
 			}
 			defer func() {
-				err := debugPod.Clean()
+				err := newdebugPod.Clean()
 				if err != nil {
-					fmt.Printf("failed cleaning debug pod %s: %v", debugPod, err)
+					fmt.Printf("failed cleaning debug pod %s: %v", newdebugPod, err)
 				}
 			}()
 
-			cds, ssTCP, ssUDP, err := ss.CreateSSOutputFromNode(debugPod, &node)
+			cds, ssTCP, ssUDP, err := ss.CreateSSOutputFromNode(newdebugPod, &node)
 			if err != nil {
 				return err
 			}

debug/debug.go

@@ -1,5 +1,8 @@
 package debug
 
+//go:generate mockgen -destination=debug_mock.go -package=debug . DebugPodInterface
+//go:generate mockgen -destination=new_debug_mock.go -package=debug . NewDebugPodInterface
+
 import (
 	"context"
 	"errors"
@@ -17,20 +20,36 @@ import (
 	"github.com/openshift-kni/commatrix/client"
 )
 
+type DebugPodInterface interface {
+	ExecWithRetry(command string, interval time.Duration, duration time.Duration) ([]byte, error)
+	Clean() error
+	GetNodeName() string
+}
+
+type NewDebugPodInterface interface {
+	New(cs *client.ClientSet, node string, namespace string, image string) (DebugPodInterface, error)
+}
+
+type NewDebugPod struct{}
+
 type DebugPod struct {
 	Name      string
 	Namespace string
 	NodeName  string
 }
 
+func (dp *DebugPod) GetNodeName() string {
+	return dp.NodeName
+}
+
 const (
 	interval = 1 * time.Second
 	timeout  = 2 * time.Minute
 )
 
 // New creates debug pod on the given node, puts it in infinite sleep,
 // and returns the DebugPod object. Use the Clean() method to delete it.
-func New(cs *client.ClientSet, node string, namespace string, image string) (*DebugPod, error) {
+func (n *NewDebugPod) New(cs *client.ClientSet, node string, namespace string, image string) (DebugPodInterface, error) {
 	if namespace == "" {
 		return nil, errors.New("failed creating new debug pod: got empty namespace")
 	}

go.mod

@@ -4,9 +4,11 @@ go 1.21
 
 require (
 	github.com/gocarina/gocsv v0.0.0-20231116093920-b87c2d0e983a
+	github.com/golang/mock v1.6.0
 	github.com/openshift/client-go v0.0.0-20240415214935-be70f772f157
 	github.com/sirupsen/logrus v1.9.3
 	github.com/stretchr/testify v1.8.4
+	go.uber.org/mock v0.4.0
 	k8s.io/api v0.29.3
 	k8s.io/apimachinery v0.29.3
 	k8s.io/client-go v0.29.3
@@ -16,6 +18,7 @@ require (
 )
 
 require (
+	github.com/evanphx/json-patch v4.12.0+incompatible // indirect
 	github.com/openshift/api v0.0.0-20240415161129-d7aff303fa1a // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 )