[YUNIKORN-469]Implement recycling service in PlaceholderManager that cleans up orphan placeholders

pkg/cache/placeholder_manager.go

@@ -20,6 +20,7 @@ package cache
 
 import (
 	"sync"
+	"time"
 
 	"go.uber.org/zap"
 	v1 "k8s.io/api/core/v1"
@@ -97,3 +98,22 @@ func (mgr *PlaceholderManager) setMockedClients(mockedClients *client.Clients) {
 	defer mgr.Unlock()
 	mgr.clients = mockedClients
 }
+
+func (mgr *PlaceholderManager) cleanOrphanPlaceholders() {
+	for taskID, pod := range mgr.orphanPod {
+		err := mgr.clients.KubeClient.Delete(pod)
+		if err == nil {
+			delete(mgr.orphanPod, taskID)
+		}
+	}
+}
+
+func (mgr *PlaceholderManager) Start() {
+	go func() {
+		for {
+			// clean orphan placeholders every 5 seconds
+			mgr.cleanOrphanPlaceholders()
+			time.Sleep(5 * time.Second)
+		}
+	}()
+}

pkg/cache/placeholder_manager_test.go

@@ -173,3 +173,26 @@ func TestCleanUp(t *testing.T) {
 	assert.Equal(t, exist, false)
 	assert.Equal(t, len(placeholderMgr.orphanPod), 0)
 }
+
+func TestCleanOrphanPlaceholders(t *testing.T) {
+	mockedAPIProvider := client.NewMockedAPIProvider()
+	placeholderMgr := &PlaceholderManager{
+		clients:   mockedAPIProvider.GetAPIs(),
+		orphanPod: make(map[string]*v1.Pod),
+		RWMutex:   sync.RWMutex{},
+	}
+	pod1 := &v1.Pod{
+		TypeMeta: apis.TypeMeta{
+			Kind:       "Pod",
+			APIVersion: "v1",
+		},
+		ObjectMeta: apis.ObjectMeta{
+			Name: "pod-01",
+			UID:  "UID-01",
+		},
+	}
+	placeholderMgr.orphanPod["task01"] = pod1
+	assert.Equal(t, len(placeholderMgr.orphanPod), 1)
+	placeholderMgr.cleanOrphanPlaceholders()
+	assert.Equal(t, len(placeholderMgr.orphanPod), 0)
+}