feat(metaserver): support get pod by uid

Signed-off-by: linzhecheng <linzhecheng@bytedance.com>

pkg/metaserver/agent/agent_test.go

@@ -25,6 +25,7 @@ import (
 	v1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/client-go/kubernetes/fake"
 	corev1 "k8s.io/client-go/kubernetes/typed/core/v1"
 
@@ -68,6 +69,7 @@ func constructPodFetcher(names []string) pod.PodFetcher {
 		pods = append(pods, &v1.Pod{
 			ObjectMeta: metav1.ObjectMeta{
 				Name: name,
+				UID:  types.UID(name + "-uid"),
 			},
 		})
 	}
@@ -94,6 +96,10 @@ func TestFetcher(t *testing.T) {
 	assert.NoError(t, err)
 	assert.Equal(t, 2, len(podObjList))
 
+	pod1, err := agent.GetPod(ctx, "test-pod-1-uid")
+	assert.NoError(t, err)
+	assert.Equal(t, "test-pod-1", pod1.Name)
+
 	nodeObj, err := agent.GetNode(ctx)
 	assert.NoError(t, err)
 	assert.Equal(t, "test-node-1", nodeObj.Name)

pkg/metaserver/agent/pod/kubelet.go

@@ -35,18 +35,26 @@ type KubeletPodFetcher interface {
 // kubeletPodFetcherImpl use kubelet 10255 pods interface to get pod directly without cache.
 type kubeletPodFetcherImpl struct{}
 
-// GetPodList get pods from kubelet 10255/pods api, and the returned slice does not
-// contain pods that don't pass `podFilter`
-func (k *kubeletPodFetcherImpl) GetPodList(_ context.Context, podFilter func(*v1.Pod) bool) ([]*v1.Pod, error) {
+func getPodsByKubeletAPI() (v1.PodList, error) {
 	const podsApi = "http://localhost:10255/pods"
 
 	var podList v1.PodList
 	err := process.GetAndUnmarshal(podsApi, &podList)
 	if err != nil {
-		return []*v1.Pod{}, fmt.Errorf("failed to get pod list, error: %v", err)
+		return podList, fmt.Errorf("failed to get pod list, error: %v", err)
 	} else if len(podList.Items) == 0 {
 		// kubelet should at least contain current pod as an item
-		return []*v1.Pod{}, fmt.Errorf("kubelet returns empty pod list")
+		return podList, fmt.Errorf("kubelet returns empty pod list")
+	}
+	return podList, nil
+}
+
+// GetPodList get pods from kubelet 10255/pods api, and the returned slice does not
+// contain pods that don't pass `podFilter`
+func (k *kubeletPodFetcherImpl) GetPodList(_ context.Context, podFilter func(*v1.Pod) bool) ([]*v1.Pod, error) {
+	podList, err := getPodsByKubeletAPI()
+	if err != nil {
+		return nil, err
 	}
 
 	var pods []*v1.Pod

pkg/metaserver/agent/pod/pod.go

@@ -57,11 +57,13 @@ type PodFetcher interface {
 	// GetContainerID & GetContainerSpec are used to parse running container info
 	GetContainerID(podUID, containerName string) (string, error)
 	GetContainerSpec(podUID, containerName string) (*v1.Container, error)
+	// GetPod returns Pod by UID
+	GetPod(ctx context.Context, podUID string) (*v1.Pod, error)
 }
 
 type podFetcherImpl struct {
 	kubeletPodFetcher KubeletPodFetcher
-	runtimePodFetcher *RuntimePodFetcher
+	runtimePodFetcher RuntimePodFetcher
 
 	kubeletPodsCache     map[string]*v1.Pod
 	kubeletPodsCacheLock sync.RWMutex
@@ -197,6 +199,17 @@ func (w *podFetcherImpl) GetPodList(ctx context.Context, podFilter func(*v1.Pod)
 	return res, nil
 }
 
+func (w *podFetcherImpl) GetPod(ctx context.Context, podUID string) (*v1.Pod, error) {
+	kubeletPodsCache, err := w.getKubeletPodsCache(ctx)
+	if err != nil {
+		return nil, fmt.Errorf("getKubeletPodsCache failed with error: %v", err)
+	}
+	if pod, ok := kubeletPodsCache[podUID]; ok {
+		return pod, nil
+	}
+	return nil, fmt.Errorf("failed to find pod by uid %v", podUID)
+}
+
 func (w *podFetcherImpl) getKubeletPodsCache(ctx context.Context) (map[string]*v1.Pod, error) {
 	// if current kubelet pod cache is nil or enforce bypass, we sync cache first
 	w.kubeletPodsCacheLock.RLock()

pkg/metaserver/agent/pod/pod_stub.go

@@ -46,6 +46,17 @@ func (p *PodFetcherStub) GetPodList(_ context.Context, podFilter func(*v1.Pod) b
 	return pods, nil
 }
 
+func (p *PodFetcherStub) GetPod(_ context.Context, podUID string) (*v1.Pod, error) {
+	p.mutex.Lock()
+	defer p.mutex.Unlock()
+	for _, pod := range p.PodList {
+		if string(pod.UID) == podUID {
+			return pod, nil
+		}
+	}
+	return nil, fmt.Errorf("failed to find pod by uid %v", podUID)
+}
+
 func (p *PodFetcherStub) Run(_ context.Context) {}
 
 func (p *PodFetcherStub) GetContainerID(podUID, containerName string) (string, error) {

pkg/metaserver/agent/pod/runtime.go

@@ -55,23 +55,27 @@ type labeledContainerInfo struct {
 	PodUID        kubetypes.UID
 }
 
-type RuntimePodFetcher struct {
+type RuntimePodFetcher interface {
+	GetPods(all bool) ([]*RuntimePod, error)
+}
+
+type RuntimePodFetcherImpl struct {
 	runtimeService cri.RuntimeService
 }
 
-func NewRuntimePodFetcher(conf *config.Configuration) (*RuntimePodFetcher, error) {
+func NewRuntimePodFetcher(conf *config.Configuration) (*RuntimePodFetcherImpl, error) {
 	runtimeService, err := remote.NewRemoteRuntimeService(conf.RemoteRuntimeEndpoint, 2*time.Minute)
 	if err != nil {
 		return nil, fmt.Errorf("create remote runtime service failed %s", err)
 	}
 
-	return &RuntimePodFetcher{runtimeService: runtimeService}, nil
+	return &RuntimePodFetcherImpl{runtimeService: runtimeService}, nil
 }
 
 // GetPods returns a list of containers grouped by pods. The boolean parameter
 // specifies whether the runtime returns all containers including those already
 // exited and dead containers (used for garbage collection).
-func (r *RuntimePodFetcher) GetPods(all bool) ([]*RuntimePod, error) {
+func (r *RuntimePodFetcherImpl) GetPods(all bool) ([]*RuntimePod, error) {
 	pods := make(map[kubetypes.UID]*RuntimePod)
 	sandboxes, err := r.getKubeletSandboxes(all)
 	if err != nil {
@@ -129,7 +133,7 @@ func (r *RuntimePodFetcher) GetPods(all bool) ([]*RuntimePod, error) {
 }
 
 // getKubeletSandboxes lists all (or just the running) sandboxes managed by kubelet.
-func (r *RuntimePodFetcher) getKubeletSandboxes(all bool) ([]*runtimeapi.PodSandbox, error) {
+func (r *RuntimePodFetcherImpl) getKubeletSandboxes(all bool) ([]*runtimeapi.PodSandbox, error) {
 	var filter *runtimeapi.PodSandboxFilter
 	if !all {
 		readyState := runtimeapi.PodSandboxState_SANDBOX_READY
@@ -152,7 +156,7 @@ func (r *RuntimePodFetcher) getKubeletSandboxes(all bool) ([]*runtimeapi.PodSand
 // getKubeletContainers lists containers managed by kubelet.
 // The boolean parameter specifies whether returns all containers including
 // those already exited and dead containers (used for garbage collection).
-func (r *RuntimePodFetcher) getKubeletContainers(allContainers bool) ([]*runtimeapi.Container, error) {
+func (r *RuntimePodFetcherImpl) getKubeletContainers(allContainers bool) ([]*runtimeapi.Container, error) {
 	filter := &runtimeapi.ContainerFilter{}
 	if !allContainers {
 		filter.State = &runtimeapi.ContainerStateValue{