Add e2e test logic for device plugin

pkg/kubelet/cm/deviceplugin/device_plugin_stub.go

@@ -38,6 +38,18 @@ type Stub struct {
 	update chan []*pluginapi.Device
 
 	server *grpc.Server
+
+	// allocFunc is used for handling allocation request
+	allocFunc stubAllocFunc
+}
+
+// stubAllocFunc is the function called when receive an allocation request from Kubelet
+type stubAllocFunc func(r *pluginapi.AllocateRequest, devs map[string]pluginapi.Device) (*pluginapi.AllocateResponse, error)
+
+func defaultAllocFunc(r *pluginapi.AllocateRequest, devs map[string]pluginapi.Device) (*pluginapi.AllocateResponse, error) {
+	var response pluginapi.AllocateResponse
+
+	return &response, nil
 }
 
 // NewDevicePluginStub returns an initialized DevicePlugin Stub.
@@ -48,9 +60,16 @@ func NewDevicePluginStub(devs []*pluginapi.Device, socket string) *Stub {
 
 		stop:   make(chan interface{}),
 		update: make(chan []*pluginapi.Device),
+
+		allocFunc: defaultAllocFunc,
 	}
 }
 
+// SetAllocFunc sets allocFunc of the device plugin
+func (m *Stub) SetAllocFunc(f stubAllocFunc) {
+	m.allocFunc = f
+}
+
 // Start starts the gRPC server of the device plugin
 func (m *Stub) Start() error {
 	err := m.cleanup()
@@ -145,8 +164,13 @@ func (m *Stub) Update(devs []*pluginapi.Device) {
 func (m *Stub) Allocate(ctx context.Context, r *pluginapi.AllocateRequest) (*pluginapi.AllocateResponse, error) {
 	log.Printf("Allocate, %+v", r)
 
-	var response pluginapi.AllocateResponse
-	return &response, nil
+	devs := make(map[string]pluginapi.Device)
+
+	for _, dev := range m.devs {
+		devs[dev.ID] = *dev
+	}
+
+	return m.allocFunc(r, devs)
 }
 
 func (m *Stub) cleanup() error {

test/e2e_node/device_plugin.go

@@ -40,7 +40,130 @@ import (
 	. "github.com/onsi/gomega"
 )
 
-// makeBusyboxPod returns a simple Pod spec with a pause container
+const (
+	// fake resource name
+	resourceName = "fake.com/resource"
+)
+
+// Serial because the test restarts Kubelet
+var _ = framework.KubeDescribe("Device Plugin [Feature:DevicePlugin] [Serial] [Disruptive]", func() {
+	f := framework.NewDefaultFramework("device-plugin-errors")
+
+	Context("DevicePlugin", func() {
+		By("Enabling support for Device Plugin")
+		tempSetCurrentKubeletConfig(f, func(initialConfig *kubeletconfig.KubeletConfiguration) {
+			initialConfig.FeatureGates[string(features.DevicePlugins)] = true
+		})
+
+		It("Verifies the Kubelet device plugin functionality.", func() {
+
+			By("Wait for node is ready")
+			framework.WaitForAllNodesSchedulable(f.ClientSet, framework.TestContext.NodeSchedulableTimeout)
+
+			By("Start stub device plugin")
+			// fake devices for e2e test
+			devs := []*pluginapi.Device{
+				{ID: "Dev-1", Health: pluginapi.Healthy},
+				{ID: "Dev-2", Health: pluginapi.Healthy},
+			}
+
+			socketPath := pluginapi.DevicePluginPath + "dp." + fmt.Sprintf("%d", time.Now().Unix())
+
+			dp1 := dp.NewDevicePluginStub(devs, socketPath)
+			dp1.SetAllocFunc(stubAllocFunc)
+			err := dp1.Start()
+			framework.ExpectNoError(err)
+
+			By("Register resources")
+			err = dp1.Register(pluginapi.KubeletSocket, resourceName)
+			framework.ExpectNoError(err)
+
+			By("Waiting for the resource exported by the stub device plugin to become available on the local node")
+			devsLen := int64(len(devs))
+			Eventually(func() int64 {
+				node, err := f.ClientSet.CoreV1().Nodes().Get(framework.TestContext.NodeName, metav1.GetOptions{})
+				framework.ExpectNoError(err)
+				return numberOfDevices(node, resourceName)
+			}, 30*time.Second, framework.Poll).Should(Equal(devsLen))
+
+			By("Creating one pod on node with at least one fake-device")
+			podRECMD := "devs=$(ls /tmp/ | egrep '^Dev-[0-9]+$') && echo stub devices: $devs"
+			pod1 := f.PodClient().CreateSync(makeBusyboxPod(resourceName, podRECMD))
+			deviceIDRE := "stub devices: (Dev-[0-9]+)"
+			count1, devId1 := parseLogFromNRuns(f, pod1.Name, pod1.Name, 0, deviceIDRE)
+			Expect(devId1).To(Not(Equal("")))
+
+			pod1, err = f.PodClient().Get(pod1.Name, metav1.GetOptions{})
+			framework.ExpectNoError(err)
+
+			By("Restarting Kubelet and waiting for the current running pod to restart")
+			restartKubelet()
+
+			By("Confirming that after a kubelet and pod restart, fake-device assignement is kept")
+			count1, devIdRestart1 := parseLogFromNRuns(f, pod1.Name, pod1.Name, count1+1, deviceIDRE)
+			Expect(devIdRestart1).To(Equal(devId1))
+
+			By("Wait for node is ready")
+			framework.WaitForAllNodesSchedulable(f.ClientSet, framework.TestContext.NodeSchedulableTimeout)
+
+			By("Re-Register resources")
+			dp1 = dp.NewDevicePluginStub(devs, socketPath)
+			dp1.SetAllocFunc(stubAllocFunc)
+			err = dp1.Start()
+			framework.ExpectNoError(err)
+
+			err = dp1.Register(pluginapi.KubeletSocket, resourceName)
+			framework.ExpectNoError(err)
+
+			By("Waiting for resource to become available on the local node after re-registration")
+			Eventually(func() int64 {
+				node, err := f.ClientSet.CoreV1().Nodes().Get(framework.TestContext.NodeName, metav1.GetOptions{})
+				framework.ExpectNoError(err)
+				return numberOfDevices(node, resourceName)
+			}, 30*time.Second, framework.Poll).Should(Equal(devsLen))
+
+			By("Creating another pod")
+			pod2 := f.PodClient().CreateSync(makeBusyboxPod(resourceName, podRECMD))
+
+			By("Checking that pods got a different GPU")
+			count2, devId2 := parseLogFromNRuns(f, pod2.Name, pod2.Name, 1, deviceIDRE)
+
+			Expect(devId1).To(Not(Equal(devId2)))
+
+			By("Deleting device plugin.")
+			err = dp1.Stop()
+			framework.ExpectNoError(err)
+
+			By("Waiting for stub device plugin to become unavailable on the local node")
+			Eventually(func() bool {
+				node, err := f.ClientSet.CoreV1().Nodes().Get(framework.TestContext.NodeName, metav1.GetOptions{})
+				framework.ExpectNoError(err)
+				return numberOfDevices(node, resourceName) <= 0
+			}, 10*time.Minute, framework.Poll).Should(BeTrue())
+
+			By("Checking that scheduled pods can continue to run even after we delete device plugin.")
+			count1, devIdRestart1 = parseLogFromNRuns(f, pod1.Name, pod1.Name, count1+1, deviceIDRE)
+			Expect(devIdRestart1).To(Equal(devId1))
+			count2, devIdRestart2 := parseLogFromNRuns(f, pod2.Name, pod2.Name, count2+1, deviceIDRE)
+			Expect(devIdRestart2).To(Equal(devId2))
+
+			By("Restarting Kubelet.")
+			restartKubelet()
+
+			By("Checking that scheduled pods can continue to run even after we delete device plugin and restart Kubelet.")
+			count1, devIdRestart1 = parseLogFromNRuns(f, pod1.Name, pod1.Name, count1+2, deviceIDRE)
+			Expect(devIdRestart1).To(Equal(devId1))
+			count2, devIdRestart2 = parseLogFromNRuns(f, pod2.Name, pod2.Name, count2+2, deviceIDRE)
+			Expect(devIdRestart2).To(Equal(devId2))
+
+			// Cleanup
+			f.PodClient().DeleteSync(pod1.Name, &metav1.DeleteOptions{}, framework.DefaultPodDeletionTimeout)
+			f.PodClient().DeleteSync(pod2.Name, &metav1.DeleteOptions{}, framework.DefaultPodDeletionTimeout)
+		})
+	})
+})
+
+// makeBusyboxPod returns a simple Pod spec with a busybox container
 // that requests resourceName and runs the specified command.
 func makeBusyboxPod(resourceName, cmd string) *v1.Pod {
 	podName := "device-plugin-test-" + string(uuid.NewUUID())
@@ -78,16 +201,19 @@ func parseLogFromNRuns(f *framework.Framework, podName string, contName string,
 		count = p.Status.ContainerStatuses[0].RestartCount
 		return count >= restartCount
 	}, 5*time.Minute, framework.Poll).Should(BeTrue())
+
 	logs, err := framework.GetPodLogs(f.ClientSet, f.Namespace.Name, podName, contName)
 	if err != nil {
 		framework.Failf("GetPodLogs for pod %q failed: %v", podName, err)
 	}
+
 	framework.Logf("got pod logs: %v", logs)
 	regex := regexp.MustCompile(re)
 	matches := regex.FindStringSubmatch(logs)
 	if len(matches) < 2 {
 		return count, ""
 	}
+
 	return count, matches[1]
 }
 
@@ -100,3 +226,37 @@ func numberOfDevices(node *v1.Node, resourceName string) int64 {
 
 	return val.Value()
 }
+
+// stubAllocFunc will pass to stub device plugin
+func stubAllocFunc(r *pluginapi.AllocateRequest, devs map[string]pluginapi.Device) (*pluginapi.AllocateResponse, error) {
+	var response pluginapi.AllocateResponse
+	for _, requestID := range r.DevicesIDs {
+		dev, ok := devs[requestID]
+		if !ok {
+			return nil, fmt.Errorf("invalid allocation request with non-existing device %s", requestID)
+		}
+
+		if dev.Health != pluginapi.Healthy {
+			return nil, fmt.Errorf("invalid allocation request with unhealthy device: %s", requestID)
+		}
+
+		// create fake device file
+		fpath := filepath.Join("/tmp", dev.ID)
+
+		// clean first
+		os.RemoveAll(fpath)
+		f, err := os.Create(fpath)
+		if err != nil && !os.IsExist(err) {
+			return nil, fmt.Errorf("failed to create fake device file: %s", err)
+		}
+
+		f.Close()
+
+		response.Mounts = append(response.Mounts, &pluginapi.Mount{
+			ContainerPath: fpath,
+			HostPath:      fpath,
+		})
+	}
+
+	return &response, nil
+}

test/e2e_node/util.go

@@ -24,6 +24,7 @@ import (
 	"net/http"
 	"os/exec"
 	"reflect"
+	"regexp"
 	"strings"
 	"time"