fix: After upgrading the operator to 1.18.3 from any previous 1.18 version the SGCluster can not be updated

Author: teoincontatto

stackgres-k8s/src/operator/src/main/java/io/stackgres/operator/mutation/cluster/UpdateStrategyMutator.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2019 OnGres, Inc.
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+package io.stackgres.operator.mutation.cluster;
+
+import java.util.Arrays;
+import java.util.Optional;
+
+import io.stackgres.common.StackGresVersion;
+import io.stackgres.common.crd.sgcluster.StackGresCluster;
+import io.stackgres.common.crd.sgcluster.StackGresClusterPods;
+import io.stackgres.common.crd.sgcluster.StackGresClusterSpec;
+import io.stackgres.common.crd.sgcluster.StackGresClusterUpdateStrategy;
+import io.stackgres.common.crd.sgcluster.StackGresClusterUpdateStrategyType;
+import io.stackgres.operator.common.StackGresClusterReview;
+import io.stackgres.operatorframework.admissionwebhook.Operation;
+import jakarta.enterprise.context.ApplicationScoped;
+
+@ApplicationScoped
+public class UpdateStrategyMutator implements ClusterMutator {
+
+  @Override
+  public StackGresCluster mutate(StackGresClusterReview review, StackGresCluster resource) {
+    if (review.getRequest().getOperation() != Operation.CREATE
+        && review.getRequest().getOperation() != Operation.UPDATE) {
+      return resource;
+    }
+    //TODO: remove this mutator when 1.18 reach EOL
+    if (StackGresVersion.V_1_18.getVersion() != null) {
+      if (Arrays.asList(StackGresClusterUpdateStrategyType.values())
+          .stream()
+          .map(Object::toString)
+          .noneMatch(
+              Optional.of(resource)
+              .map(StackGresCluster::getSpec)
+              .map(StackGresClusterSpec::getPods)
+              .map(StackGresClusterPods::getUpdateStrategy)
+              .map(StackGresClusterUpdateStrategy::getType)
+              .orElse("")::equals)) {
+        if (resource.getSpec() == null) {
+          resource.setSpec(new StackGresClusterSpec());
+        }
+        if (resource.getSpec().getPods() == null) {
+          resource.getSpec().setPods(new StackGresClusterPods());
+        }
+        if (resource.getSpec().getPods().getUpdateStrategy() == null) {
+          resource.getSpec().getPods().setUpdateStrategy(new StackGresClusterUpdateStrategy());
+        }
+        resource.getSpec().getPods().getUpdateStrategy().setType(
+            StackGresClusterUpdateStrategyType.ONLY_DB_OPS.toString());
+      }
+    }
+
+    return resource;
+  }
+
+}