refactor: move missing NS checking logic to Operator

Author: metacosm

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/Operator.java

@@ -12,6 +12,7 @@
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Objects;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -137,21 +138,39 @@ public <R extends CustomResource> void register(
       controller.init(eventSourceManager);
       closeables.add(eventSourceManager);
 
-      final var effectiveNamespaces = configuration.getEffectiveNamespaces();
-      if (configuration.isCurrentNamespaceMissing() && configuration.watchCurrentNamespace()) {
+      if (failOnMissingCurrentNS(configuration)) {
         throw new OperatorException(
             "Controller '"
                 + controllerName
-                + "' is configured to watch the current namespace but it couldn't be inferred from the current configuration. ");
+                + "' is configured to watch the current namespace but it couldn't be inferred from the current configuration.");
       }
 
       final var watchedNS =
-          configuration.watchAllNamespaces() ? "[all namespaces]" : effectiveNamespaces;
+          configuration.watchAllNamespaces()
+              ? "[all namespaces]"
+              : configuration.getEffectiveNamespaces();
       log.info(
           "Registered Controller: '{}' for CRD: '{}' for namespace(s): {}",
           controllerName,
           resClass,
           watchedNS);
     }
   }
+
+  /**
+   * Determines whether we should fail because the current namespace is request as target namespace
+   * but is missing
+   *
+   * @return {@code true} if the current namespace is requested but is missing, {@code false}
+   *     otherwise
+   */
+  private static <R extends CustomResource> boolean failOnMissingCurrentNS(
+      ControllerConfiguration<R> configuration) {
+    if (configuration.watchCurrentNamespace()) {
+      final var effectiveNamespaces = configuration.getEffectiveNamespaces();
+      return effectiveNamespaces.size() == 1
+          && effectiveNamespaces.stream().allMatch(Objects::isNull);
+    }
+    return false;
+  }
 }

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/config/ControllerConfiguration.java

@@ -3,7 +3,6 @@
 import io.fabric8.kubernetes.client.CustomResource;
 import io.javaoperatorsdk.operator.api.Controller;
 import java.util.Collections;
-import java.util.Objects;
 import java.util.Set;
 
 public interface ControllerConfiguration<R extends CustomResource> {
@@ -62,12 +61,6 @@ default Set<String> getEffectiveNamespaces() {
     return targetNamespaces;
   }
 
-  default boolean isCurrentNamespaceMissing() {
-    final var effectiveNamespaces = getEffectiveNamespaces();
-    return effectiveNamespaces.size() == 1
-        && effectiveNamespaces.stream().allMatch(Objects::isNull);
-  }
-
   default RetryConfiguration getRetryConfiguration() {
     return RetryConfiguration.DEFAULT;
   }