[YUNIKORN-521] Placeholder pods are not cleaned when the job is deleted

pkg/appmgmt/general/general.go

@@ -130,6 +130,7 @@ func (os *Manager) getAppMetadata(pod *v1.Pod) (interfaces.ApplicationMetadata,
 		User:          user,
 		Tags:          tags,
 		TaskGroups:    taskGroups,
+		PlaceholderOwnerReferences: pod.OwnerReferences,
 	}, true
 }
 

pkg/appmgmt/interfaces/amprotocol.go

@@ -20,6 +20,7 @@ package interfaces
 
 import (
 	v1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 
 	"github.com/apache/incubator-yunikorn-k8shim/pkg/apis/yunikorn.apache.org/v1alpha1"
 )
@@ -75,6 +76,7 @@ type ApplicationMetadata struct {
 	User          string
 	Tags          map[string]string
 	TaskGroups    []v1alpha1.TaskGroup
+	PlaceholderOwnerReferences []metav1.OwnerReference
 }
 
 type TaskMetadata struct {

pkg/cache/application.go

@@ -26,6 +26,7 @@ import (
 	"github.com/looplab/fsm"
 	"go.uber.org/zap"
 	v1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 
 	"github.com/apache/incubator-yunikorn-core/pkg/api"
 	"github.com/apache/incubator-yunikorn-k8shim/pkg/apis/yunikorn.apache.org/v1alpha1"
@@ -40,17 +41,18 @@ import (
 )
 
 type Application struct {
-	applicationID    string
-	queue            string
-	partition        string
-	user             string
-	taskMap          map[string]*Task
-	tags             map[string]string
-	schedulingPolicy v1alpha1.SchedulingPolicy
-	taskGroups       []v1alpha1.TaskGroup
-	sm               *fsm.FSM
-	lock             *sync.RWMutex
-	schedulerAPI     api.SchedulerAPI
+	applicationID              string
+	queue                      string
+	partition                  string
+	user                       string
+	taskMap                    map[string]*Task
+	tags                       map[string]string
+	schedulingPolicy           v1alpha1.SchedulingPolicy
+	taskGroups                 []v1alpha1.TaskGroup
+	placeholderOwnerReferences []metav1.OwnerReference
+	sm                         *fsm.FSM
+	lock                       *sync.RWMutex
+	schedulerAPI               api.SchedulerAPI
 }
 
 func (app *Application) String() string {
@@ -208,6 +210,12 @@ func (app *Application) getTaskGroups() []v1alpha1.TaskGroup {
 	return app.taskGroups
 }
 
+func (app *Application) setPlaceholderOwnReference(ref []metav1.OwnerReference) {
+	app.lock.RLock()
+	defer app.lock.RUnlock()
+	app.placeholderOwnerReferences = ref
+}
+
 func (app *Application) addTask(task *Task) {
 	app.lock.Lock()
 	defer app.lock.Unlock()

pkg/cache/context.go

@@ -499,6 +499,7 @@ func (ctx *Context) AddApplication(request *interfaces.AddApplicationRequest) in
 		request.Metadata.Tags,
 		ctx.apiProvider.GetAPIs().SchedulerAPI)
 	app.setTaskGroups(request.Metadata.TaskGroups)
+	app.setPlaceholderOwnReference(request.Metadata.PlaceholderOwnerReferences)
 
 	// add into cache
 	ctx.applications[app.applicationID] = app

pkg/cache/placeholder.go

@@ -36,6 +36,11 @@ type Placeholder struct {
 }
 
 func newPlaceholder(placeholderName string, app *Application, taskGroup v1alpha1.TaskGroup) *Placeholder {
+	ownerRef := app.placeholderOwnerReferences
+	controller := false
+	for _, r := range ownerRef {
+		*r.Controller = controller
+	}
 	placeholderPod := &v1.Pod{
 		ObjectMeta: metav1.ObjectMeta{
 			Name:      placeholderName,
@@ -48,6 +53,7 @@ func newPlaceholder(placeholderName string, app *Application, taskGroup v1alpha1
 				constants.AnnotationPlaceholderFlag: "true",
 				constants.AnnotationTaskGroupName:   taskGroup.Name,
 			},
+			OwnerReferences: ownerRef,
 		},
 		Spec: v1.PodSpec{
 			Containers: []v1.Container{