From d1d0cee7807836b87622c5a0d8f32a76b2783725 Mon Sep 17 00:00:00 2001
From: Rohan Kumar <rohankmr414@gmail.com>
Date: Sat, 25 Jun 2022 19:50:55 +0530
Subject: [PATCH] feat: add finalizer to workflow pod to prevent "pod deleted"

Signed-off-by: Rohan Kumar <rohankmr414@gmail.com>
---
 workflow/common/common.go          |  2 ++
 workflow/controller/controller.go  | 15 +++++++++++++--
 workflow/controller/workflowpod.go |  1 +
 3 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/workflow/common/common.go b/workflow/common/common.go
index 3af8521e87ac..97588d6c64c2 100644
--- a/workflow/common/common.go
+++ b/workflow/common/common.go
@@ -223,6 +223,8 @@ const (
 	ErrDeadlineExceeded = "DeadlineExceeded"
 
 	ConfigMapName = "workflow-controller-configmap"
+
+	WorkflowFinalizer = "argoproj.io/workflow-finalizer"
 )
 
 // AnnotationKeyKillCmd specifies the command to use to kill to container, useful for injected sidecars
diff --git a/workflow/controller/controller.go b/workflow/controller/controller.go
index df063d6c400b..b9ad388d3ede 100644
--- a/workflow/controller/controller.go
+++ b/workflow/controller/controller.go
@@ -490,15 +490,26 @@ func (wfc *WorkflowController) processNextPodCleanupItem(ctx context.Context) bo
 				ctx,
 				podName,
 				types.MergePatchType,
-				[]byte(`{"metadata": {"labels": {"workflows.argoproj.io/completed": "true"}}}`),
+				[]byte(`{"metadata": {"labels": {"workflows.argoproj.io/completed": "true"}, "finalizers": []}}`),
 				metav1.PatchOptions{},
 			)
 			if err != nil {
 				return err
 			}
 		case deletePod:
+			// remove the finalizer to allow the pod to be deleted
+			_, err := pods.Patch(
+				ctx,
+				podName,
+				types.MergePatchType,
+				[]byte(`{"metadata": {"finalizers": []}}`),
+				metav1.PatchOptions{},
+			)
+			if err != nil {
+				return err
+			}
 			propagation := metav1.DeletePropagationBackground
-			err := pods.Delete(ctx, podName, metav1.DeleteOptions{
+			err = pods.Delete(ctx, podName, metav1.DeleteOptions{
 				PropagationPolicy:  &propagation,
 				GracePeriodSeconds: wfc.Config.PodGCGracePeriodSeconds,
 			})
diff --git a/workflow/controller/workflowpod.go b/workflow/controller/workflowpod.go
index f8e0bc0e4428..a987e943b860 100644
--- a/workflow/controller/workflowpod.go
+++ b/workflow/controller/workflowpod.go
@@ -172,6 +172,7 @@ func (woc *wfOperationCtx) createWorkflowPod(ctx context.Context, nodeName strin
 			OwnerReferences: []metav1.OwnerReference{
 				*metav1.NewControllerRef(woc.wf, wfv1.SchemeGroupVersion.WithKind(workflow.WorkflowKind)),
 			},
+			Finalizers: []string{common.WorkflowFinalizer},
 		},
 		Spec: apiv1.PodSpec{
 			RestartPolicy:         apiv1.RestartPolicyNever,