Extract app framework into reusable engine for Standalone architecture (#1778)

* Extract App Framework pipeline into reusable internal engine

Signed-off-by: jzywieck <jzywiecki@splunk.com>

* Extract app framework pipeline into engine for standalone

Signed-off-by: jzywieck <jzywiecki@splunk.com>

* Add doc comments to the app engine

Signed-off-by: jzywieck <jzywiecki@splunk.com>

---------

Signed-off-by: jzywieck <jzywiecki@splunk.com>

Author: jzywiecki

api/v4/common_types.go

@@ -47,6 +47,9 @@ const (
 	RepoStatePassive
 )
 
+// ScopeType represent the scope of the App Source
+type ScopeType string
+
 // Values to represent the App Source scope
 const (
 	ScopeLocal                = "local"

internal/controller/standalone_controller.go

@@ -113,7 +113,7 @@ func (r *StandaloneReconciler) Reconcile(ctx context.Context, req ctrl.Request)
 	// Pass event recorder through context
 	ctx = context.WithValue(ctx, splcommon.EventRecorderKey, r.Recorder)
 
-	result, err := ApplyStandalone(ctx, r.Client, instance)
+	result, err := ApplyStandalone(ctx, r.Client, instance, enterprise.NewAppFrameworkEngine())
 	if result.Requeue && result.RequeueAfter != 0 {
 		reqLogger.Info("Requeued", "period(seconds)", int(result.RequeueAfter/time.Second))
 	}
@@ -122,8 +122,8 @@ func (r *StandaloneReconciler) Reconcile(ctx context.Context, req ctrl.Request)
 }
 
 // ApplyStandalone adding to handle unit test case
-var ApplyStandalone = func(ctx context.Context, client client.Client, instance *enterpriseApi.Standalone) (reconcile.Result, error) {
-	return enterprise.ApplyStandalone(ctx, client, instance)
+var ApplyStandalone = func(ctx context.Context, client client.Client, instance *enterpriseApi.Standalone, appEngine enterprise.AppEngine) (reconcile.Result, error) {
+	return enterprise.ApplyStandalone(ctx, client, instance, appEngine)
 }
 
 // SetupWithManager sets up the controller with the Manager.

internal/controller/standalone_controller_test.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"github.com/splunk/splunk-operator/internal/controller/testutils"
+	enterprise "github.com/splunk/splunk-operator/pkg/splunk/enterprise"
 
 	enterpriseApi "github.com/splunk/splunk-operator/api/v4"
 
@@ -38,7 +39,7 @@ var _ = Describe("Standalone Controller", func() {
 
 		It("Get Standalone custom resource should failed", func() {
 			namespace := "ns-splunk-st-1"
-			ApplyStandalone = func(ctx context.Context, client client.Client, instance *enterpriseApi.Standalone) (reconcile.Result, error) {
+			ApplyStandalone = func(ctx context.Context, client client.Client, instance *enterpriseApi.Standalone, appEngine enterprise.AppEngine) (reconcile.Result, error) {
 				return reconcile.Result{}, nil
 			}
 			nsSpecs := &corev1.Namespace{ObjectMeta: metav1.ObjectMeta{Name: namespace}}
@@ -51,7 +52,7 @@ var _ = Describe("Standalone Controller", func() {
 
 		It("Create Standalone custom resource with annotations should pause", func() {
 			namespace := "ns-splunk-st-2"
-			ApplyStandalone = func(ctx context.Context, client client.Client, instance *enterpriseApi.Standalone) (reconcile.Result, error) {
+			ApplyStandalone = func(ctx context.Context, client client.Client, instance *enterpriseApi.Standalone, appEngine enterprise.AppEngine) (reconcile.Result, error) {
 				return reconcile.Result{}, nil
 			}
 			nsSpecs := &corev1.Namespace{ObjectMeta: metav1.ObjectMeta{Name: namespace}}
@@ -70,7 +71,7 @@ var _ = Describe("Standalone Controller", func() {
 
 		It("Create Standalone custom resource should succeeded", func() {
 			namespace := "ns-splunk-st-3"
-			ApplyStandalone = func(ctx context.Context, client client.Client, instance *enterpriseApi.Standalone) (reconcile.Result, error) {
+			ApplyStandalone = func(ctx context.Context, client client.Client, instance *enterpriseApi.Standalone, appEngine enterprise.AppEngine) (reconcile.Result, error) {
 				return reconcile.Result{}, nil
 			}
 			nsSpecs := &corev1.Namespace{ObjectMeta: metav1.ObjectMeta{Name: namespace}}
@@ -83,7 +84,7 @@ var _ = Describe("Standalone Controller", func() {
 
 		It("Cover Unused methods", func() {
 			namespace := "ns-splunk-st-4"
-			ApplyStandalone = func(ctx context.Context, client client.Client, instance *enterpriseApi.Standalone) (reconcile.Result, error) {
+			ApplyStandalone = func(ctx context.Context, client client.Client, instance *enterpriseApi.Standalone, appEngine enterprise.AppEngine) (reconcile.Result, error) {
 				return reconcile.Result{}, nil
 			}
 			nsSpecs := &corev1.Namespace{ObjectMeta: metav1.ObjectMeta{Name: namespace}}

pkg/splunk/enterprise/appengine.go

@@ -0,0 +1,81 @@
+/*
+Copyright (c) 2018-2026 Splunk Inc. All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// Package enterprise provides core Splunk Enterprise reconciliation logic.
+package enterprise
+
+import (
+	"context"
+
+	enterpriseApi "github.com/splunk/splunk-operator/api/v4"
+	splcommon "github.com/splunk/splunk-operator/pkg/splunk/common"
+	corev1 "k8s.io/api/core/v1"
+	"sigs.k8s.io/controller-runtime/pkg/reconcile"
+)
+
+// AppEngine defines the app framework operations used during reconciliation.
+type AppEngine interface {
+	ensureAppFrameworkStatus(ctx context.Context, client splcommon.ControllerClient, target splcommon.MetaObject, appDeployContext *enterpriseApi.AppDeploymentContext, appFrameworkConfig *enterpriseApi.AppFrameworkSpec, scope enterpriseApi.ScopeType) error
+	ensureAppRepoState(ctx context.Context, client splcommon.ControllerClient, target splcommon.MetaObject, appFrameworkConfig *enterpriseApi.AppFrameworkSpec, appDeployContext *enterpriseApi.AppDeploymentContext) error
+	runAppFrameworkIfReady(ctx context.Context, client splcommon.ControllerClient, target splcommon.MetaObject, appDeployContext *enterpriseApi.AppDeploymentContext, appFrameworkConfig *enterpriseApi.AppFrameworkSpec) *reconcile.Result
+	ensureAppFrameworkStagingVolume(ctx context.Context, client splcommon.ControllerClient, target splcommon.MetaObject, podTemplateSpec *corev1.PodTemplateSpec, appFrameworkConfig *enterpriseApi.AppFrameworkSpec)
+	changeAppSrcDeployInfoStatus(ctx context.Context, appSrc string, appSrcDeployStatus map[string]enterpriseApi.AppSrcDeployInfo, repoState enterpriseApi.AppRepoState, oldDeployStatus enterpriseApi.AppDeploymentStatus, newDeployStatus enterpriseApi.AppDeploymentStatus)
+	changePhaseInfo(ctx context.Context, desiredReplicas int32, appSrc string, appSrcDeployStatus map[string]enterpriseApi.AppSrcDeployInfo)
+	removeStaleEntriesFromAuxPhaseInfo(ctx context.Context, desiredReplicas int32, appSrc string, appSrcDeployStatus map[string]enterpriseApi.AppSrcDeployInfo)
+}
+
+// appFrameworkEngine is the default AppEngine implementation.
+type appFrameworkEngine struct{}
+
+// NewAppFrameworkEngine returns a default AppEngine implementation.
+func NewAppFrameworkEngine() AppEngine {
+	return &appFrameworkEngine{}
+}
+
+// ensureAppFrameworkStatus validates and migrates app framework status when needed.
+func (e *appFrameworkEngine) ensureAppFrameworkStatus(ctx context.Context, client splcommon.ControllerClient, target splcommon.MetaObject, appDeployContext *enterpriseApi.AppDeploymentContext, appFrameworkConfig *enterpriseApi.AppFrameworkSpec, scope enterpriseApi.ScopeType) error {
+	return checkAndMigrateAppDeployStatus(ctx, client, target, appDeployContext, appFrameworkConfig, scope == enterpriseApi.ScopeLocal)
+}
+
+// ensureAppRepoState initializes clients and checks remote app status when app framework is configured.
+func (e *appFrameworkEngine) ensureAppRepoState(ctx context.Context, client splcommon.ControllerClient, target splcommon.MetaObject, appFrameworkConfig *enterpriseApi.AppFrameworkSpec, appDeployContext *enterpriseApi.AppDeploymentContext) error {
+	return initAndCheckAppInfoStatus(ctx, client, target, appFrameworkConfig, appDeployContext)
+}
+
+// runAppFrameworkIfReady runs the app framework pipeline only when the CR is ready.
+func (e *appFrameworkEngine) runAppFrameworkIfReady(ctx context.Context, client splcommon.ControllerClient, target splcommon.MetaObject, appDeployContext *enterpriseApi.AppDeploymentContext, appFrameworkConfig *enterpriseApi.AppFrameworkSpec) *reconcile.Result {
+	return handleAppFrameworkActivity(ctx, client, target, appDeployContext, appFrameworkConfig)
+}
+
+// changePhaseInfo updates deployment phase tracking for the given app source.
+func (e *appFrameworkEngine) changePhaseInfo(ctx context.Context, desiredReplicas int32, appSrc string, appSrcDeployStatus map[string]enterpriseApi.AppSrcDeployInfo) {
+	changePhaseInfo(ctx, desiredReplicas, appSrc, appSrcDeployStatus)
+}
+
+// removeStaleEntriesFromAuxPhaseInfo trims aux phase tracking entries.
+func (e *appFrameworkEngine) removeStaleEntriesFromAuxPhaseInfo(ctx context.Context, desiredReplicas int32, appSrc string, appSrcDeployStatus map[string]enterpriseApi.AppSrcDeployInfo) {
+	removeStaleEntriesFromAuxPhaseInfo(ctx, desiredReplicas, appSrc, appSrcDeployStatus)
+}
+
+// changeAppSrcDeployInfoStatus records a deployment status transition.
+func (e *appFrameworkEngine) changeAppSrcDeployInfoStatus(ctx context.Context, appSrc string, appSrcDeployStatus map[string]enterpriseApi.AppSrcDeployInfo, repoState enterpriseApi.AppRepoState, oldDeployStatus enterpriseApi.AppDeploymentStatus, newDeployStatus enterpriseApi.AppDeploymentStatus) {
+	changeAppSrcDeployInfoStatus(ctx, appSrc, appSrcDeployStatus, repoState, oldDeployStatus, newDeployStatus)
+}
+
+// ensureAppFrameworkStagingVolume adds the staging volume for app framework use.
+func (e *appFrameworkEngine) ensureAppFrameworkStagingVolume(ctx context.Context, client splcommon.ControllerClient, target splcommon.MetaObject, podTemplateSpec *corev1.PodTemplateSpec, appFrameworkConfig *enterpriseApi.AppFrameworkSpec) {
+	setupAppsStagingVolume(ctx, client, target, podTemplateSpec, appFrameworkConfig)
+}

pkg/splunk/enterprise/configuration_test.go

@@ -286,7 +286,7 @@ func TestSmartstoreApplyStandaloneFailsOnInvalidSmartStoreConfig(t *testing.T) {
 
 	client := spltest.NewMockClient()
 
-	_, err := ApplyStandalone(context.Background(), client, &cr)
+	_, err := ApplyStandalone(context.Background(), client, &cr, NewAppFrameworkEngine())
 	if err == nil {
 		t.Errorf("ApplyStandalone should fail on invalid smartstore config")
 	}

pkg/splunk/enterprise/standalone.go

@@ -35,7 +35,7 @@ import (
 )
 
 // ApplyStandalone reconciles the StatefulSet for N standalone instances of Splunk Enterprise.
-func ApplyStandalone(ctx context.Context, client splcommon.ControllerClient, cr *enterpriseApi.Standalone) (reconcile.Result, error) {
+func ApplyStandalone(ctx context.Context, client splcommon.ControllerClient, cr *enterpriseApi.Standalone, appEngine AppEngine) (reconcile.Result, error) {
 
 	// unless modified, reconcile for this object will be requeued after 5 seconds
 	result := reconcile.Result{
@@ -72,7 +72,7 @@ func ApplyStandalone(ctx context.Context, client splcommon.ControllerClient, cr
 	cr.Status.Replicas = cr.Spec.Replicas
 
 	// If needed, Migrate the app framework status
-	err = checkAndMigrateAppDeployStatus(ctx, client, cr, &cr.Status.AppContext, &cr.Spec.AppFrameworkConfig, true)
+	err = appEngine.ensureAppFrameworkStatus(ctx, client, cr, &cr.Status.AppContext, &cr.Spec.AppFrameworkConfig, enterpriseApi.ScopeLocal)
 	if err != nil {
 		return result, err
 	}
@@ -97,9 +97,9 @@ func ApplyStandalone(ctx context.Context, client splcommon.ControllerClient, cr
 	// 1. Initialize the S3Clients based on providers
 	// 2. Check the status of apps on remote storage.
 	if len(cr.Spec.AppFrameworkConfig.AppSources) != 0 {
-		err := initAndCheckAppInfoStatus(ctx, client, cr, &cr.Spec.AppFrameworkConfig, &cr.Status.AppContext)
+		err := appEngine.ensureAppRepoState(ctx, client, cr, &cr.Spec.AppFrameworkConfig, &cr.Status.AppContext)
 		if err != nil {
-			eventPublisher.Warning(ctx, "initAndCheckAppInfoStatus", fmt.Sprintf("init and check app info status failed %s", err.Error()))
+			eventPublisher.Warning(ctx, "ensureAppRepoState", fmt.Sprintf("ensure app repo state failed %s", err.Error()))
 			cr.Status.AppContext.IsDeploymentInProgress = false
 			return result, err
 		}
@@ -187,22 +187,22 @@ func ApplyStandalone(ctx context.Context, client splcommon.ControllerClient, cr
 			cr.Status.AppContext.IsDeploymentInProgress = true
 
 			for appSrc := range appStatusContext.AppsSrcDeployStatus {
-				changeAppSrcDeployInfoStatus(ctx, appSrc, appStatusContext.AppsSrcDeployStatus, enterpriseApi.RepoStateActive, enterpriseApi.DeployStatusComplete, enterpriseApi.DeployStatusPending)
-				changePhaseInfo(ctx, cr.Spec.Replicas, appSrc, appStatusContext.AppsSrcDeployStatus)
+				appEngine.changeAppSrcDeployInfoStatus(ctx, appSrc, appStatusContext.AppsSrcDeployStatus, enterpriseApi.RepoStateActive, enterpriseApi.DeployStatusComplete, enterpriseApi.DeployStatusPending)
+				appEngine.changePhaseInfo(ctx, cr.Spec.Replicas, appSrc, appStatusContext.AppsSrcDeployStatus)
 			}
 
 		// if we are scaling down, just delete the state auxPhaseInfo entries
 		case enterpriseApi.StatefulSetScalingDown:
 			for appSrc := range appStatusContext.AppsSrcDeployStatus {
-				removeStaleEntriesFromAuxPhaseInfo(ctx, cr.Spec.Replicas, appSrc, appStatusContext.AppsSrcDeployStatus)
+				appEngine.removeStaleEntriesFromAuxPhaseInfo(ctx, cr.Spec.Replicas, appSrc, appStatusContext.AppsSrcDeployStatus)
 			}
 		default:
 			// nothing to be done
 		}
 	}
 
 	// create or update statefulset
-	statefulSet, err := getStandaloneStatefulSet(ctx, client, cr)
+	statefulSet, err := getStandaloneStatefulSet(ctx, client, cr, appEngine)
 	if err != nil {
 		eventPublisher.Warning(ctx, "getStandaloneStatefulSet", fmt.Sprintf("get standalone status set failed %s", err.Error()))
 		return result, err
@@ -262,7 +262,7 @@ func ApplyStandalone(ctx context.Context, client splcommon.ControllerClient, cr
 			scopedLog.Error(err, "Error in deleting automated monitoring console resource")
 		}
 
-		finalResult := handleAppFrameworkActivity(ctx, client, cr, &cr.Status.AppContext, &cr.Spec.AppFrameworkConfig)
+		finalResult := appEngine.runAppFrameworkIfReady(ctx, client, cr, &cr.Status.AppContext, &cr.Spec.AppFrameworkConfig)
 		result = *finalResult
 
 		// Add a splunk operator telemetry app
@@ -287,7 +287,7 @@ func ApplyStandalone(ctx context.Context, client splcommon.ControllerClient, cr
 }
 
 // getStandaloneStatefulSet returns a Kubernetes StatefulSet object for Splunk Enterprise standalone instances.
-func getStandaloneStatefulSet(ctx context.Context, client splcommon.ControllerClient, cr *enterpriseApi.Standalone) (*appsv1.StatefulSet, error) {
+func getStandaloneStatefulSet(ctx context.Context, client splcommon.ControllerClient, cr *enterpriseApi.Standalone, appEngine AppEngine) (*appsv1.StatefulSet, error) {
 	// get generic statefulset for Splunk Enterprise objects
 	ss, err := getSplunkStatefulSet(ctx, client, cr, &cr.Spec.CommonSplunkSpec, SplunkStandalone, cr.Spec.Replicas, []corev1.EnvVar{})
 	if err != nil {
@@ -301,7 +301,7 @@ func getStandaloneStatefulSet(ctx context.Context, client splcommon.ControllerCl
 	}
 
 	// Setup App framework staging volume for apps
-	setupAppsStagingVolume(ctx, client, cr, &ss.Spec.Template, &cr.Spec.AppFrameworkConfig)
+	appEngine.ensureAppFrameworkStagingVolume(ctx, client, cr, &ss.Spec.Template, &cr.Spec.AppFrameworkConfig)
 
 	return ss, nil
 }