fix issue 1558 (#1559)

Fixes #1558

spring-cloud-kubernetes-client-discovery/src/main/java/org/springframework/cloud/kubernetes/client/discovery/KubernetesClientInformerSelectiveNamespacesAutoConfiguration.java

@@ -67,10 +67,8 @@ public class KubernetesClientInformerSelectiveNamespacesAutoConfiguration {
 			LogFactory.getLog(KubernetesClientInformerSelectiveNamespacesAutoConfiguration.class));
 
 	// we rely on the order of namespaces to enable listers, as such provide a bean of
-	// namespaces
-	// as a list, instead of the incoming Set.
+	// namespaces as a list, instead of the incoming Set.
 	@Bean
-	@ConditionalOnMissingBean
 	public List<String> selectiveNamespaces(KubernetesDiscoveryProperties properties) {
 		List<String> selectiveNamespaces = properties.namespaces().stream().sorted().toList();
 		LOG.debug(() -> "using selective namespaces : " + selectiveNamespaces);

spring-cloud-kubernetes-client-discovery/src/test/java/org/springframework/cloud/kubernetes/client/discovery/KubernetesClientInformerSelectiveNamespacesAutoConfigurationTests.java

@@ -0,0 +1,113 @@
+/*
+ * Copyright 2019-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.cloud.kubernetes.client.discovery;
+
+import java.util.List;
+import java.util.Set;
+
+import io.kubernetes.client.openapi.ApiClient;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mockito;
+
+import org.springframework.boot.autoconfigure.AutoConfigurations;
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+import org.springframework.boot.test.system.CapturedOutput;
+import org.springframework.boot.test.system.OutputCaptureExtension;
+import org.springframework.cloud.kubernetes.commons.discovery.KubernetesDiscoveryProperties;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * @author wind57
+ */
+@ExtendWith(OutputCaptureExtension.class)
+class KubernetesClientInformerSelectiveNamespacesAutoConfigurationTests {
+
+	private static final String NAMESPACE_A = "a";
+
+	private static final String NAMESPACE_B = "b";
+
+	private static final String NAMESPACE_C = "c";
+
+	private static final String NAMESPACE_D = "d";
+
+	@Test
+	void testBeansCreates(CapturedOutput output) {
+
+		new ApplicationContextRunner()
+				.withPropertyValues("spring.cloud.discovery.enabled=true",
+						"spring.cloud.kubernetes.discovery.enabled=true",
+						"spring.cloud.kubernetes.discovery.namespaces[0]=" + NAMESPACE_A,
+						"spring.cloud.kubernetes.discovery.namespaces[1]=" + NAMESPACE_B,
+						"spring.main.cloud-platform=kubernetes")
+				.withConfiguration(
+						AutoConfigurations.of(KubernetesClientInformerSelectiveNamespacesAutoConfiguration.class))
+				.withUserConfiguration(Config.class).run(context -> {
+					assertThat(context.getBean("selectiveNamespaces")).isNotNull();
+
+					@SuppressWarnings("unchecked")
+					Set<String> selectiveNamespaces = context.getBean("selectiveNamespaces", Set.class);
+					Assertions.assertEquals(selectiveNamespaces, Set.of("a", "b"));
+
+					@SuppressWarnings("unchecked")
+					Set<String> namespaces = context.getBean("namespaces", Set.class);
+					Assertions.assertEquals(namespaces, Set.of("c", "d"));
+				});
+
+		assertThat(output.getOut().contains("registering lister (for services) in namespace : " + NAMESPACE_A))
+				.isTrue();
+		assertThat(output.getOut().contains("registering lister (for services) in namespace : " + NAMESPACE_B))
+				.isTrue();
+
+		assertThat(output.getOut().contains("registering lister (for services) in namespace : " + NAMESPACE_C))
+				.isFalse();
+		assertThat(output.getOut().contains("registering lister (for services) in namespace : " + NAMESPACE_D))
+				.isFalse();
+
+		assertThat(output.getOut().contains("registering lister (for endpoints) in namespace : " + NAMESPACE_A))
+				.isTrue();
+		assertThat(output.getOut().contains("registering lister (for endpoints) in namespace : " + NAMESPACE_B))
+				.isTrue();
+
+		assertThat(output.getOut().contains("registering lister (for endpoints) in namespace : " + NAMESPACE_C))
+				.isFalse();
+		assertThat(output.getOut().contains("registering lister (for endpoints) in namespace : " + NAMESPACE_D))
+				.isFalse();
+	}
+
+	@Configuration
+	@EnableConfigurationProperties(KubernetesDiscoveryProperties.class)
+	static class Config {
+
+		@Bean
+		ApiClient apiClient() {
+			return Mockito.mock(ApiClient.class);
+		}
+
+		@Bean
+		List<String> namespaces() {
+			return List.of(NAMESPACE_C, NAMESPACE_D);
+		}
+
+	}
+
+}