Issue argoproj#1665 - Stuck processor on App Controller after deletin…

…g application with incomplete operation

controller/appcontroller.go

@@ -551,6 +551,10 @@ func (ctrl *ApplicationController) setOperationState(app *appv1.Application, sta
 		appClient := ctrl.applicationClientset.ArgoprojV1alpha1().Applications(ctrl.namespace)
 		_, err = appClient.Patch(app.Name, types.MergePatchType, patchJSON)
 		if err != nil {
+			// Stop retrying updating deleted application
+			if apierr.IsNotFound(err) {
+				return nil
+			}
 			return err
 		}
 		log.Infof("updated '%s' operation (phase: %s)", app.Name, state.Phase)

controller/appcontroller_test.go

@@ -5,19 +5,21 @@ import (
 	"testing"
 	"time"
 
-	"github.com/argoproj/argo-cd/common"
+	"k8s.io/apimachinery/pkg/runtime/schema"
 
 	"github.com/ghodss/yaml"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/mock"
 	corev1 "k8s.io/api/core/v1"
+	apierr "k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/client-go/kubernetes/fake"
 	kubetesting "k8s.io/client-go/testing"
 	"k8s.io/client-go/tools/cache"
 
+	"github.com/argoproj/argo-cd/common"
 	mockstatecache "github.com/argoproj/argo-cd/controller/cache/mocks"
 	argoappv1 "github.com/argoproj/argo-cd/pkg/apis/application/v1alpha1"
 	appclientset "github.com/argoproj/argo-cd/pkg/client/clientset/versioned/fake"
@@ -467,3 +469,16 @@ func TestHandleAppUpdated(t *testing.T) {
 	isRequested, _ = ctrl.isRefreshRequested(app.Name)
 	assert.True(t, isRequested)
 }
+
+func TestSetOperationStateOnDeletedApp(t *testing.T) {
+	ctrl := newFakeController(&fakeData{apps: []runtime.Object{}})
+	fakeAppCs := ctrl.applicationClientset.(*appclientset.Clientset)
+	fakeAppCs.ReactionChain = nil
+	patched := false
+	fakeAppCs.AddReactor("patch", "*", func(action kubetesting.Action) (handled bool, ret runtime.Object, err error) {
+		patched = true
+		return true, nil, apierr.NewNotFound(schema.GroupResource{}, "my-app")
+	})
+	ctrl.setOperationState(newFakeApp(), &argoappv1.OperationState{Phase: argoappv1.OperationSucceeded})
+	assert.True(t, patched)
+}