Add priority class support for Velero server and node-agent

- Add --server-priority-class-name and --node-agent-priority-class-name flags to velero install command
- Configure data mover pods (PVB/PVR/DataUpload/DataDownload) to use priority class from node-agent-configmap
- Update e2e tests to include PriorityClass label for testing
- Move priority class design document to Implemented folder
- Add changelog entry for velero-io#8883

🤖 Generated with [Claude Code](https://claude.ai/code)

Signed-off-by: Tiger Kaovilai <tkaovila@redhat.com>

Add support for ConfigMap options in Velero server installation

Signed-off-by: Tiger Kaovilai <tkaovila@redhat.com>

Implement centralized ConfigMap watching for node-agent controllers

This change introduces a centralized ConfigMap watching mechanism to eliminate
redundant ConfigMap watchers across controllers. Previously, each controller
(PodVolumeBackup, PodVolumeRestore, DataUpload, DataDownload) independently
watched the same ConfigMap, leading to inefficiency.

Key changes:
- Add ConfigProvider interface for centralized configuration management
- Implement nodeAgentConfigProvider with single ConfigMap watcher
- Update all controllers to use ConfigProvider instead of direct watching
- Add comprehensive unit tests for ConfigProvider implementation
- Add enhanced MockConfigProvider for testing
- Add E2E test for validating centralized watching behavior
- Remove redundant ConfigMap watching code from controllers

Benefits:
- Single source of truth for ConfigMap watching
- Reduced resource usage with one watcher instead of four
- Consistent configuration updates across all controllers
- Improved testability with centralized mocking
- Better separation of concerns

🤖 Generated with [Claude Code](https://claude.ai/code)

Fix ConfigProvider tests for empty ConfigMap name and informer behavior

- Handle empty ConfigMap name gracefully in NewNodeAgentConfigProvider
- Skip informer start when ConfigMap name is empty
- Update test expectations to handle informer Add events on startup
- Ensure tests pass with correct behavior for edge cases

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: kaovilai

changelogs/unreleased/8883-kaovilai

@@ -0,0 +1 @@
+Implement PriorityClass Support

…gn/priority-class-name-support_design.md …ed/priority-class-name-support_design.mddesign/priority-class-name-support_design.md renamed to design/Implemented/priority-class-name-support_design.md design/priority-class-name-support_design.md renamed to design/Implemented/priority-class-name-support_design.md

@@ -17,6 +17,7 @@ limitations under the License.
 package install
 
 import (
+	"context"
 	"fmt"
 	"os"
 	"path/filepath"
@@ -26,6 +27,7 @@ import (
 	"github.com/vmware-tanzu/velero/pkg/uploader"
 
 	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
 	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
@@ -91,6 +93,8 @@ type Options struct {
 	ItemBlockWorkerCount            int
 	NodeAgentDisableHostPath        bool
 	kubeletRootDir                  string
+	ServerPriorityClassName         string
+	NodeAgentPriorityClassName      string
 }
 
 // BindFlags adds command line values to the options struct.
@@ -194,6 +198,18 @@ func (o *Options) BindFlags(flags *pflag.FlagSet) {
 		o.ItemBlockWorkerCount,
 		"Number of worker threads to process ItemBlocks. Default is one. Optional.",
 	)
+	flags.StringVar(
+		&o.ServerPriorityClassName,
+		"server-priority-class-name",
+		o.ServerPriorityClassName,
+		"Priority class name for the Velero server deployment. Optional.",
+	)
+	flags.StringVar(
+		&o.NodeAgentPriorityClassName,
+		"node-agent-priority-class-name",
+		o.NodeAgentPriorityClassName,
+		"Priority class name for the node agent daemonset. Optional.",
+	)
 }
 
 // NewInstallOptions instantiates a new, default InstallOptions struct.
@@ -301,6 +317,8 @@ func (o *Options) AsVeleroOptions() (*install.VeleroOptions, error) {
 		ItemBlockWorkerCount:            o.ItemBlockWorkerCount,
 		KubeletRootDir:                  o.kubeletRootDir,
 		NodeAgentDisableHostPath:        o.NodeAgentDisableHostPath,
+		ServerPriorityClassName:         o.ServerPriorityClassName,
+		NodeAgentPriorityClassName:      o.NodeAgentPriorityClassName,
 	}, nil
 }
 
@@ -389,6 +407,25 @@ func (o *Options) Run(c *cobra.Command, f client.Factory) error {
 	if err != nil {
 		return err
 	}
+
+	// Get Kubernetes client for priority class validation
+	kubeClient, err := f.KubeClient()
+	if err != nil {
+		return err
+	}
+
+	// Validate priority classes if specified
+	logger := logrus.New()
+	logger.SetOutput(os.Stdout)
+	if o.ServerPriorityClassName != "" {
+		_ = kubeutil.ValidatePriorityClass(context.Background(), kubeClient, o.ServerPriorityClassName, logger.WithField("component", "server"))
+		// For install command, we continue even if validation fails (warnings are logged)
+	}
+	if o.NodeAgentPriorityClassName != "" {
+		_ = kubeutil.ValidatePriorityClass(context.Background(), kubeClient, o.NodeAgentPriorityClassName, logger.WithField("component", "node-agent"))
+		// For install command, we continue even if validation fails (warnings are logged)
+	}
+
 	errorMsg := fmt.Sprintf("\n\nError installing Velero. Use `kubectl logs deploy/velero -n %s` to check the deploy logs", o.Namespace)
 
 	err = install.Install(dynamicFactory, kbClient, resources, os.Stdout)

pkg/cmd/cli/install/install.go

@@ -0,0 +1,93 @@
+/*
+Copyright the Velero contributors.
+
+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 install
+
+import (
+	"testing"
+
+	"github.com/spf13/pflag"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestPriorityClassNameFlag(t *testing.T) {
+	// Test that the flag is properly defined
+	o := NewInstallOptions()
+	flags := pflag.NewFlagSet("test", pflag.ContinueOnError)
+	o.BindFlags(flags)
+
+	// Verify the server priority class flag exists
+	serverFlag := flags.Lookup("server-priority-class-name")
+	assert.NotNil(t, serverFlag, "server-priority-class-name flag should exist")
+	assert.Equal(t, "Priority class name for the Velero server deployment. Optional.", serverFlag.Usage)
+
+	// Verify the node agent priority class flag exists
+	nodeAgentFlag := flags.Lookup("node-agent-priority-class-name")
+	assert.NotNil(t, nodeAgentFlag, "node-agent-priority-class-name flag should exist")
+	assert.Equal(t, "Priority class name for the node agent daemonset. Optional.", nodeAgentFlag.Usage)
+
+	// Test with values for both server and node agent
+	testCases := []struct {
+		name                       string
+		serverPriorityClassName    string
+		nodeAgentPriorityClassName string
+		expectedServerValue        string
+		expectedNodeAgentValue     string
+	}{
+		{
+			name:                       "with both priority class names",
+			serverPriorityClassName:    "high-priority",
+			nodeAgentPriorityClassName: "medium-priority",
+			expectedServerValue:        "high-priority",
+			expectedNodeAgentValue:     "medium-priority",
+		},
+		{
+			name:                       "with only server priority class name",
+			serverPriorityClassName:    "high-priority",
+			nodeAgentPriorityClassName: "",
+			expectedServerValue:        "high-priority",
+			expectedNodeAgentValue:     "",
+		},
+		{
+			name:                       "with only node agent priority class name",
+			serverPriorityClassName:    "",
+			nodeAgentPriorityClassName: "medium-priority",
+			expectedServerValue:        "",
+			expectedNodeAgentValue:     "medium-priority",
+		},
+		{
+			name:                       "without priority class names",
+			serverPriorityClassName:    "",
+			nodeAgentPriorityClassName: "",
+			expectedServerValue:        "",
+			expectedNodeAgentValue:     "",
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			o := NewInstallOptions()
+			o.ServerPriorityClassName = tc.serverPriorityClassName
+			o.NodeAgentPriorityClassName = tc.nodeAgentPriorityClassName
+
+			veleroOptions, err := o.AsVeleroOptions()
+			require.NoError(t, err)
+			assert.Equal(t, tc.expectedServerValue, veleroOptions.ServerPriorityClassName)
+			assert.Equal(t, tc.expectedNodeAgentValue, veleroOptions.NodeAgentPriorityClassName)
+		})
+	}
+}

pkg/cmd/cli/install/install_test.go

@@ -280,6 +280,25 @@ func (s *nodeAgentServer) run() {
 
 	s.logger.Info("Starting controllers")
 
+	// Read priority class from ConfigMap if available
+	dataMovePriorityClass := ""
+	if s.config.nodeAgentConfig != "" {
+		ctx, cancel := context.WithTimeout(context.Background(), time.Second*30)
+		defer cancel()
+		priorityClass, err := kube.GetDataMoverPriorityClassName(ctx, s.namespace, s.kubeClient, s.config.nodeAgentConfig)
+		if err != nil {
+			s.logger.WithError(err).Warn("Failed to get priority class name from node-agent-configmap, using empty value")
+		} else if priorityClass != "" {
+			// Validate the priority class exists in the cluster
+			if kube.ValidatePriorityClass(ctx, s.kubeClient, priorityClass, s.logger.WithField("component", "data-mover")) {
+				dataMovePriorityClass = priorityClass
+				s.logger.WithField("priorityClassName", priorityClass).Info("Using priority class for data mover pods")
+			} else {
+				s.logger.WithField("priorityClassName", priorityClass).Warn("Priority class not found in cluster, data mover pods will use default priority")
+			}
+		}
+	}
+
 	var loadAffinity []*kube.LoadAffinity
 	if s.dataPathConfigs != nil && len(s.dataPathConfigs.LoadAffinity) > 0 {
 		loadAffinity = s.dataPathConfigs.LoadAffinity
@@ -311,12 +330,12 @@ func (s *nodeAgentServer) run() {
 		}
 	}
 
-	pvbReconciler := controller.NewPodVolumeBackupReconciler(s.mgr.GetClient(), s.mgr, s.kubeClient, s.dataPathMgr, s.vgdpCounter, s.nodeName, s.config.dataMoverPrepareTimeout, s.config.resourceTimeout, podResources, s.metrics, s.logger)
+	pvbReconciler := controller.NewPodVolumeBackupReconciler(s.mgr.GetClient(), s.mgr, s.kubeClient, s.dataPathMgr, s.vgdpCounter, s.nodeName, s.config.dataMoverPrepareTimeout, s.config.resourceTimeout, podResources, s.metrics, s.logger, dataMovePriorityClass)
 	if err := pvbReconciler.SetupWithManager(s.mgr); err != nil {
 		s.logger.Fatal(err, "unable to create controller", "controller", constant.ControllerPodVolumeBackup)
 	}
 
-	pvrReconciler := controller.NewPodVolumeRestoreReconciler(s.mgr.GetClient(), s.mgr, s.kubeClient, s.dataPathMgr, s.vgdpCounter, s.nodeName, s.config.dataMoverPrepareTimeout, s.config.resourceTimeout, podResources, s.logger)
+	pvrReconciler := controller.NewPodVolumeRestoreReconciler(s.mgr.GetClient(), s.mgr, s.kubeClient, s.dataPathMgr, s.vgdpCounter, s.nodeName, s.config.dataMoverPrepareTimeout, s.config.resourceTimeout, podResources, s.logger, dataMovePriorityClass)
 	if err := pvrReconciler.SetupWithManager(s.mgr); err != nil {
 		s.logger.WithError(err).Fatal("Unable to create the pod volume restore controller")
 	}
@@ -340,6 +359,7 @@ func (s *nodeAgentServer) run() {
 		s.config.dataMoverPrepareTimeout,
 		s.logger,
 		s.metrics,
+		dataMovePriorityClass,
 	)
 	if err := dataUploadReconciler.SetupWithManager(s.mgr); err != nil {
 		s.logger.WithError(err).Fatal("Unable to create the data upload controller")
@@ -364,6 +384,7 @@ func (s *nodeAgentServer) run() {
 		s.config.dataMoverPrepareTimeout,
 		s.logger,
 		s.metrics,
+		dataMovePriorityClass,
 	)
 
 	if err := dataDownloadReconciler.SetupWithManager(s.mgr); err != nil {

pkg/cmd/cli/nodeagent/server.go

@@ -71,6 +71,7 @@ type DataDownloadReconciler struct {
 	preparingTimeout      time.Duration
 	metrics               *metrics.ServerMetrics
 	cancelledDataDownload map[string]time.Time
+	dataMovePriorityClass string
 }
 
 func NewDataDownloadReconciler(
@@ -86,12 +87,19 @@ func NewDataDownloadReconciler(
 	preparingTimeout time.Duration,
 	logger logrus.FieldLogger,
 	metrics *metrics.ServerMetrics,
+	dataMovePriorityClass string,
 ) *DataDownloadReconciler {
+	log := logger.WithField("controller", "DataDownload")
+
+	if dataMovePriorityClass != "" {
+		log.Infof("Data mover priority class set to %q", dataMovePriorityClass)
+	}
+
 	return &DataDownloadReconciler{
 		client:                client,
 		kubeClient:            kubeClient,
 		mgr:                   mgr,
-		logger:                logger.WithField("controller", "DataDownload"),
+		logger:                log,
 		Clock:                 &clock.RealClock{},
 		nodeName:              nodeName,
 		restoreExposer:        exposer.NewGenericRestoreExposer(kubeClient, logger),
@@ -103,6 +111,7 @@ func NewDataDownloadReconciler(
 		preparingTimeout:      preparingTimeout,
 		metrics:               metrics,
 		cancelledDataDownload: make(map[string]time.Time),
+		dataMovePriorityClass: dataMovePriorityClass,
 	}
 }
 
@@ -599,7 +608,7 @@ func (r *DataDownloadReconciler) SetupWithManager(mgr ctrl.Manager) error {
 		Predicates: []predicate.Predicate{gp},
 	})
 
-	return ctrl.NewControllerManagedBy(mgr).
+	controllerBuilder := ctrl.NewControllerManagedBy(mgr).
 		For(&velerov2alpha1api.DataDownload{}).
 		WatchesRawSource(s).
 		Watches(&corev1api.Pod{}, kube.EnqueueRequestsFromMapUpdateFunc(r.findSnapshotRestoreForPod),
@@ -626,8 +635,9 @@ func (r *DataDownloadReconciler) SetupWithManager(mgr ctrl.Manager) error {
 				GenericFunc: func(ge event.GenericEvent) bool {
 					return false
 				},
-			})).
-		Complete(r)
+			}))
+
+	return controllerBuilder.Complete(r)
 }
 
 func (r *DataDownloadReconciler) findSnapshotRestoreForPod(ctx context.Context, podObj client.Object) []reconcile.Request {
@@ -892,6 +902,7 @@ func (r *DataDownloadReconciler) setupExposeParam(dd *velerov2alpha1api.DataDown
 		NodeOS:                nodeOS,
 		RestorePVCConfig:      r.restorePVCConfig,
 		LoadAffinity:          affinity,
+		PriorityClassName:     r.dataMovePriorityClass,
 	}, nil
 }
 

pkg/controller/data_download_controller.go

@@ -130,19 +130,7 @@ func initDataDownloadReconcilerWithError(t *testing.T, objects []any, needError
 
 	dataPathMgr := datapath.NewManager(1)
 
-	return NewDataDownloadReconciler(
-		&fakeClient,
-		nil,
-		fakeKubeClient,
-		dataPathMgr,
-		nil,
-		nil,
-		nodeagent.RestorePVC{},
-		corev1api.ResourceRequirements{},
-		"test-node",
-		time.Minute*5,
-		velerotest.NewLogger(),
-		metrics.NewServerMetrics()), nil
+	return NewDataDownloadReconciler(&fakeClient, nil, fakeKubeClient, dataPathMgr, nil, nil, nodeagent.RestorePVC{}, corev1api.ResourceRequirements{}, "test-node", time.Minute*5, velerotest.NewLogger(), metrics.NewServerMetrics(), ""), nil
 }
 
 func TestDataDownloadReconcile(t *testing.T) {