Add Backup warning for inclusion of NS managed by ArgoCD

Signed-off-by: Shubham Pampattiwar <spampatt@redhat.com>

add changelog file

Signed-off-by: Shubham Pampattiwar <spampatt@redhat.com>

changelogs/unreleased/8257-shubham-pampattiwar

@@ -0,0 +1 @@
+Add Backup warning for inclusion of NS managed by ArgoCD

pkg/backup/backup.go

@@ -24,6 +24,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	corev1api "k8s.io/api/core/v1"
 	"os"
 	"path/filepath"
 	"time"
@@ -71,6 +72,9 @@ const BackupVersion = 1
 // BackupFormatVersion is the current backup version for Velero, including major, minor, and patch.
 const BackupFormatVersion = "1.1.0"
 
+// ArgoCD managed by namespace label key
+const ArgoCDManagedByNamespaceLabel = "argocd.argoproj.io/managed-by"
+
 // Backupper performs backups.
 type Backupper interface {
 	// Backup takes a backup using the specification in the velerov1api.Backup and writes backup and log data
@@ -244,6 +248,15 @@ func (kb *kubernetesBackupper) BackupWithResolvers(
 	log.Infof("Including namespaces: %s", backupRequest.NamespaceIncludesExcludes.IncludesString())
 	log.Infof("Excluding namespaces: %s", backupRequest.NamespaceIncludesExcludes.ExcludesString())
 
+	// check if there are any namespaces included in the backup which are managed by argoCD
+	// We will check for the existence of a label "argocd.argoproj.io/managed-by" in the includedNamespaces and add a warning
+	// so that users are at least aware about the existence of argoCD managed ns in their backup
+	nsManagedByArgoCD := getNamespacesManagedByArgoCD(kb.kbClient, backupRequest.Spec.IncludedNamespaces, log)
+
+	if len(nsManagedByArgoCD) > 0 {
+		log.Warnf("backup operation may encounter complications and potentially produce undesirable results due to the inclusion of namespaces %v managed by ArgoCD in the backup.", nsManagedByArgoCD)
+	}
+
 	if collections.UseOldResourceFilters(backupRequest.Spec) {
 		backupRequest.ResourceIncludesExcludes = collections.GetGlobalResourceIncludesExcludes(kb.discoveryHelper, log,
 			backupRequest.Spec.IncludedResources,
@@ -1107,3 +1120,21 @@ func putVolumeInfos(
 
 	return backupStore.PutBackupVolumeInfos(backupName, backupVolumeInfoBuf)
 }
+
+func getNamespacesManagedByArgoCD(kbClient kbclient.Client, includedNamespaces []string, log logrus.FieldLogger) []string {
+	var nsManagedByArgoCD []string
+
+	for _, nsName := range includedNamespaces {
+		ns := corev1api.Namespace{}
+		if err := kbClient.Get(context.Background(), kbclient.ObjectKey{Name: nsName}, &ns); err != nil {
+			log.WithError(err).Errorf("error getting namespace %s", nsName)
+			continue
+		}
+
+		nsLabels := ns.GetLabels()
+		if len(nsLabels[ArgoCDManagedByNamespaceLabel]) > 0 {
+			nsManagedByArgoCD = append(nsManagedByArgoCD, nsName)
+		}
+	}
+	return nsManagedByArgoCD
+}