fix scale up

e2e-tests/functions

@@ -1166,6 +1166,7 @@ wait_cluster_consistency() {
 		echo -n .
 		sleep 10
 	done
+	echo
 }
 
 run_backup() {

e2e-tests/split-horizon/conf/some-name.yml

@@ -0,0 +1,33 @@
+apiVersion: psmdb.percona.com/v1
+kind: PerconaServerMongoDB
+metadata:
+  name: some-name
+spec:
+  #platform: openshift
+  image:
+  imagePullPolicy: Always
+  backup:
+    enabled: false
+    image: perconalab/percona-server-mongodb-operator:main-backup
+  replsets:
+  - name: rs0
+    size: 3
+    expose:
+      enabled: true
+      exposeType: ClusterIP
+    affinity:
+      antiAffinityTopologyKey: none
+    resources:
+      limits:
+        cpu: 500m
+        memory: 0.5G
+      requests:
+        cpu: 100m
+        memory: 0.1G
+    volumeSpec:
+      persistentVolumeClaim:
+        resources:
+          requests:
+            storage: 1Gi
+  secrets:
+    users: some-users

pkg/controller/perconaservermongodb/mgo.go

@@ -260,6 +260,15 @@ func (r *ReconcilePerconaServerMongoDB) updateConfigMembers(ctx context.Context,
 		return 0, errors.Wrap(err, "get mongo config")
 	}
 
+	existingHorizons := make([]string, 0)
+	for _, member := range cnf.Members {
+		if len(member.Horizons) > 0 {
+			for name := range member.Horizons {
+				existingHorizons = append(existingHorizons, name)
+			}
+		}
+	}
+
 	members := mongo.ConfigMembers{}
 	for key, pod := range pods.Items {
 		if key >= mongo.MaxMembers {
@@ -294,6 +303,18 @@ func (r *ReconcilePerconaServerMongoDB) updateConfigMembers(ctx context.Context,
 			Votes:        mongo.DefaultVotes,
 		}
 
+		if len(existingHorizons) > 0 {
+			for _, horizon := range existingHorizons {
+				if _, ok := rs.Horizons[pod.Name][horizon]; !ok {
+					return 0, errors.Errorf("horizon %s is missing for pod %s", horizon, pod.Name)
+				}
+
+				member.Horizons = map[string]string{
+					horizon: rs.Horizons[pod.Name][horizon],
+				}
+			}
+		}
+
 		switch pod.Labels["app.kubernetes.io/component"] {
 		case "arbiter":
 			member.ArbiterOnly = true