Merge pull request #55921 from ScorpioCPH/fix-endpoint-ut

Automatic merge from submit-queue (batch tested with PRs 58216, 58193, 53033, 58219, 55921). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Fix device plugin endpoint UT

**What this PR does / why we need it**:
Fix some issues in device plugin endpoint UT.

**Which issue(s) this PR fixes**:
Fixes #55920

**Special notes for your reviewer**:

@jiayingz @RenaudWasTaken @lichuqiang PTAL.

/sig node

**Release note**:

```release-note
None
```

pkg/kubelet/cm/deviceplugin/device_plugin_stub.go

@@ -89,7 +89,7 @@ func (m *Stub) Start() error {
 	// Wait till grpc server is ready.
 	for i := 0; i < 10; i++ {
 		services := m.server.GetServiceInfo()
-		if len(services) > 1 {
+		if len(services) > 0 {
 			break
 		}
 		time.Sleep(1 * time.Second)
@@ -134,16 +134,8 @@ func (m *Stub) Register(kubeletEndpoint, resourceName string) error {
 // ListAndWatch lists devices and update that list according to the Update call
 func (m *Stub) ListAndWatch(e *pluginapi.Empty, s pluginapi.DevicePlugin_ListAndWatchServer) error {
 	log.Println("ListAndWatch")
-	var devs []*pluginapi.Device
 
-	for _, d := range m.devs {
+	s.Send(&pluginapi.ListAndWatchResponse{Devices: m.devs})
-		devs = append(devs, &pluginapi.Device{
-			ID:     d.ID,
-			Health: pluginapi.Healthy,
-		})
-	}
-
-	s.Send(&pluginapi.ListAndWatchResponse{Devices: devs})
 
 	for {
 		select {

pkg/kubelet/cm/deviceplugin/endpoint_test.go

@@ -19,7 +19,6 @@ package deviceplugin
 import (
 	"path"
 	"testing"
-	"time"
 
 	"github.com/stretchr/testify/require"
 
@@ -54,23 +53,49 @@ func TestRun(t *testing.T) {
 		{ID: "AThirdDeviceId", Health: pluginapi.Healthy},
 	}
 
-	p, e := esetup(t, devs, socket, "mock", func(n string, a, u, r []pluginapi.Device) {
+	callbackCount := 0
+	callbackChan := make(chan int)
+	callback := func(n string, a, u, r []pluginapi.Device) {
+		// Should be called twice:
+		// one for plugin registration, one for plugin update.
+		if callbackCount > 2 {
+			t.FailNow()
+		}
+
+		// Check plugin registration
+		if callbackCount == 0 {
+			require.Len(t, a, 2)
+			require.Len(t, u, 0)
+			require.Len(t, r, 0)
+		}
+
+		// Check plugin update
+		if callbackCount == 1 {
 			require.Len(t, a, 1)
 			require.Len(t, u, 1)
 			require.Len(t, r, 1)
 
 			require.Equal(t, a[0].ID, updated[1].ID)
-
 			require.Equal(t, u[0].ID, updated[0].ID)
 			require.Equal(t, u[0].Health, updated[0].Health)
-
 			require.Equal(t, r[0].ID, devs[1].ID)
-	})
+		}
+
+		callbackCount++
+		callbackChan <- callbackCount
+	}
+
+	p, e := esetup(t, devs, socket, "mock", callback)
 	defer ecleanup(t, p, e)
 
 	go e.run()
+	// Wait for the first callback to be issued.
+	<-callbackChan
+
 	p.Update(updated)
-	time.Sleep(time.Second)
+
+	// Wait for the second callback to be issued.
+	<-callbackChan
 
 	e.mutex.Lock()
 	defer e.mutex.Unlock()
@@ -102,7 +127,7 @@ func esetup(t *testing.T, devs []*pluginapi.Device, socket, resourceName string,
 	err := p.Start()
 	require.NoError(t, err)
 
-	e, err := newEndpointImpl(socket, "mock", make(map[string]pluginapi.Device), func(n string, a, u, r []pluginapi.Device) {})
+	e, err := newEndpointImpl(socket, resourceName, make(map[string]pluginapi.Device), callback)
 	require.NoError(t, err)
 
 	return p, e