add function to cleanup maintenance addon before starting manager

Signed-off-by: Umanga Chapagain <[email protected]>

controllers/manager.go

@@ -2,6 +2,8 @@ package controllers
 
 import (
 	"context"
+	"fmt"
+	"log/slog"
 	"os"
 
 	"github.com/go-logr/zapr"
@@ -14,7 +16,11 @@ import (
 	"github.com/red-hat-storage/odf-multicluster-orchestrator/controllers/utils"
 	"github.com/spf13/cobra"
 	"golang.org/x/sync/errgroup"
+	"k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/labels"
 	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/selection"
 	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
 	"k8s.io/client-go/kubernetes"
 	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
@@ -23,6 +29,7 @@ import (
 	clusterv1 "open-cluster-management.io/api/cluster/v1"
 	workv1 "open-cluster-management.io/api/work/v1"
 	ctrl "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/client"
 	"sigs.k8s.io/controller-runtime/pkg/healthz"
 	"sigs.k8s.io/controller-runtime/pkg/manager"
 	"sigs.k8s.io/controller-runtime/pkg/metrics/server"
@@ -88,6 +95,40 @@ func NewManagerCommand() *cobra.Command {
 	return cmd
 }
 
+func preRunGarbageCollection(cl client.Client, logger *slog.Logger) error {
+	ctx := context.TODO()
+	req, err := labels.NewRequirement("openshiftVersion-major-minor", selection.In, []string{"4.16", "4.17", "4.18"})
+	if err != nil {
+		return fmt.Errorf("couldn't create ManagedCluster selector requirement. %w", err)
+	}
+
+	var managedClusters clusterv1.ManagedClusterList
+	err = cl.List(ctx, &managedClusters, &client.ListOptions{
+		LabelSelector: labels.NewSelector().Add(*req),
+	})
+	if err != nil {
+		return fmt.Errorf("couldn't list ManagedClusters. %w", err)
+	}
+	logger.Info(fmt.Sprintf("Found %v ManagedClusters matching given requirements", len(managedClusters.Items)), "Requirements", req)
+
+	for idx := range managedClusters.Items {
+		maintenanceAddon := addonapiv1alpha1.ManagedClusterAddOn{
+			ObjectMeta: metav1.ObjectMeta{
+				Name:      "maintenance",
+				Namespace: managedClusters.Items[idx].Name,
+			},
+		}
+		err = cl.Delete(ctx, &maintenanceAddon, &client.DeleteOptions{})
+		if err != nil && !errors.IsNotFound(err) {
+			return fmt.Errorf("failed to delete maintenance addon from cluster %q. %w", managedClusters.Items[idx].Name, err)
+		}
+		if err == nil || errors.IsNotFound(err) {
+			logger.Info("Deleted maintenance addon from ManagedCluster", "ManagedCluster", managedClusters.Items[idx].Name)
+		}
+	}
+	return nil
+}
+
 func (o *ManagerOptions) runManager() {
 	zapLogger := utils.GetZapLogger(o.DevMode)
 	defer func() {
@@ -98,6 +139,23 @@ func (o *ManagerOptions) runManager() {
 	ctrl.SetLogger(zapr.NewLogger(zapLogger))
 	logger := utils.GetLogger(zapLogger)
 
+	preRunClient, err := client.New(ctrl.GetConfigOrDie(), client.Options{
+		Scheme: mgrScheme,
+		Cache:  nil,
+	})
+	if err != nil {
+		logger.Error("Failed to create a client for pre-run garbage collection", "error", err)
+		os.Exit(1)
+	}
+
+	logger.Info("Starting garbage collection before starting manager")
+	err = preRunGarbageCollection(preRunClient, logger)
+	if err != nil {
+		logger.Error("Pre-run garbage collection failed", "error", err)
+		os.Exit(1)
+	}
+	logger.Info("Finished garbage collection")
+
 	srv := webhook.NewServer(webhook.Options{
 		CertDir:  WebhookCertDir,
 		CertName: WebhookCertName,