Drop databases before restore. Do not migrate objects related to backup.

Signed-off-by: Mykola Morhun <mmorhun@redhat.com>

controllers/checlusterrestore/backup_data_restorer.go

@@ -123,6 +123,9 @@ func cleanPreviousInstallation(rctx *RestoreContext, dataDir string) (bool, erro
 		rctx.cheCR = cheCR
 	}
 
+	// Drop databases, if any, to handle case of different Postgres version (otherwise clean Che will fail to start due to ald data in volume)
+	dropDatabases(rctx)
+
 	// Delete Che CR to stop operator from dealing with current installation
 	actualCheCR, cheCRCount, err := util.FindCheClusterCRInNamespace(rctx.r.cachingClient, rctx.namespace)
 	if cheCRCount == -1 {
@@ -425,6 +428,36 @@ func readBackupMetadata(rctx *RestoreContext, dataDir string) (*checlusterbackup
 	return backupMetadata, true, nil
 }
 
+// dropDatabases deletes Che related databased from Postgres, if any
+func dropDatabases(rctx *RestoreContext) {
+	if rctx.cheCR.Spec.Database.ExternalDb {
+		// Skip this step as there is an external server to connect to
+		return
+	}
+
+	databasesToDrop := []string{
+		rctx.cheCR.Spec.Database.ChePostgresDb,
+		"keycloak",
+	}
+
+	k8sClient := util.GetK8Client()
+	postgresPodName, err := k8sClient.GetDeploymentPod(deploy.PostgresName, rctx.namespace)
+	if err != nil {
+		// Postgres pod not found, probably it doesn't exist
+		return
+	}
+
+	for _, dbName := range databasesToDrop {
+		execReason := fmt.Sprintf("dropping %s database", dbName)
+		dropDatabaseCommand := fmt.Sprintf("psql -c \"DROP DATABASE IF EXISTS %s;\"", dbName)
+		if output, err := k8sClient.DoExecIntoPod(rctx.namespace, postgresPodName, dropDatabaseCommand, execReason); err != nil {
+			if output != "" {
+				logrus.Error(output)
+			}
+		}
+	}
+}
+
 func restoreDatabase(rctx *RestoreContext, dataDir string) (bool, error) {
 	if rctx.cheCR.Spec.Database.ExternalDb {
 		// Skip database restore as there is an external server to connect to

controllers/checlusterrestore/checlusterrestore_controller.go

@@ -184,7 +184,7 @@ func (r *ReconcileCheClusterRestore) doReconcile(restoreCR *chev1.CheClusterRest
 		}
 	}
 
-	// Makrctxe sure, that backup server configuration in the CR is valid and cache cluster resources
+	// Make sure, that backup server configuration in the CR is valid and cache cluster resources
 	done, err = rctx.backupServer.PrepareConfiguration(rctx.r.nonCachingClient, rctx.namespace)
 	if err != nil || !done {
 		return done, err

pkg/deploy/migration/on-reconcile-one-time-migration.go

@@ -17,6 +17,7 @@ import (
 	"fmt"
 	"time"
 
+	"github.com/eclipse-che/che-operator/controllers/checlusterbackup"
 	"github.com/eclipse-che/che-operator/pkg/deploy"
 	"github.com/eclipse-che/che-operator/pkg/util"
 	routev1 "github.com/openshift/api/route/v1"
@@ -214,12 +215,22 @@ func addPartOfLabelForObjectsWithInstanceCheLabel(ctx *deploy.DeployContext) err
 		logrus.Error(getFailedToCreateSelectorErrorMessage())
 		return err
 	}
+	// Do not migrate already migrated objects
 	notPartOfCheSelectorRequirement, err := labels.NewRequirement(deploy.KubernetesPartOfLabelKey, selection.NotEquals, []string{deploy.CheEclipseOrg})
 	if err != nil {
 		logrus.Error(getFailedToCreateSelectorErrorMessage())
 		return err
 	}
-	objectsToMigrateLabelSelector := labels.NewSelector().Add(*instanceCheSelectorRequirement).Add(*notPartOfCheSelectorRequirement)
+	// Do not migrate objects related to backup/restore
+	notPartOfCheBackupSelectorRequirement, err := labels.NewRequirement(deploy.KubernetesPartOfLabelKey, selection.NotEquals, []string{checlusterbackup.BackupCheEclipseOrg})
+	if err != nil {
+		logrus.Error(getFailedToCreateSelectorErrorMessage())
+		return err
+	}
+	objectsToMigrateLabelSelector := labels.NewSelector().
+		Add(*instanceCheSelectorRequirement).
+		Add(*notPartOfCheSelectorRequirement).
+		Add(*notPartOfCheBackupSelectorRequirement)
 	listOptions := &client.ListOptions{
 		LabelSelector: objectsToMigrateLabelSelector,
 		Namespace:     ctx.CheCluster.GetNamespace(),