Issue #635 - Decouples configMap and secret property source locators by making the… (#639)

* Decouples configMap and secret property source locators by making them optional dependencies for reload auto config as they could be enabled/disabled through config independent of each other. Fixes #635

* make ConfigurationChangeDetector conditional. only required if one of configMaps or secrets are enabled. Add Null checks for event/polling for the existence of an appropriate PropertySourceLocator

* Add ConditionalOnBean for propertyChangeWatcher to be consistent with configuration. Add tests

* remove sop

* fix checkstyle errors

* add additional classes to SpringApplicationBuilder and context

* introduce AnyNestedCondition to allow for the propertyChangeWatcher to be registered when either secrets or config or both are enabled.

spring-cloud-kubernetes-config/src/main/java/org/springframework/cloud/kubernetes/config/reload/ConfigReloadAutoConfiguration.java

@@ -24,6 +24,8 @@ import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.actuate.autoconfigure.endpoint.EndpointAutoConfiguration;
 import org.springframework.boot.actuate.autoconfigure.info.InfoEndpointAutoConfiguration;
 import org.springframework.boot.autoconfigure.AutoConfigureAfter;
+import org.springframework.boot.autoconfigure.condition.AnyNestedCondition;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
@@ -36,6 +38,7 @@ import org.springframework.cloud.kubernetes.config.ConfigMapPropertySourceLocato
 import org.springframework.cloud.kubernetes.config.SecretsPropertySourceLocator;
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Conditional;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.env.AbstractEnvironment;
 import org.springframework.scheduling.annotation.EnableAsync;
@@ -71,32 +74,28 @@ public class ConfigReloadAutoConfiguration {
 		@Autowired
 		private KubernetesClient kubernetesClient;
 
-		@Autowired
-		private ConfigMapPropertySourceLocator configMapPropertySourceLocator;
-
-		@Autowired
-		private SecretsPropertySourceLocator secretsPropertySourceLocator;
-
 		/**
 		 * @param properties config reload properties
 		 * @param strategy configuration update strategy
 		 * @return a bean that listen to configuration changes and fire a reload.
 		 */
 		@Bean
-		@ConditionalOnMissingBean
+		@Conditional(OnConfigEnabledOrSecretsEnabled.class)
 		public ConfigurationChangeDetector propertyChangeWatcher(
-				ConfigReloadProperties properties, ConfigurationUpdateStrategy strategy) {
+				ConfigReloadProperties properties, ConfigurationUpdateStrategy strategy,
+				@Autowired(
+						required = false) ConfigMapPropertySourceLocator configMapPropertySourceLocator,
+				@Autowired(
+						required = false) SecretsPropertySourceLocator secretsPropertySourceLocator) {
 			switch (properties.getMode()) {
 			case POLLING:
 				return new PollingConfigurationChangeDetector(this.environment,
 						properties, this.kubernetesClient, strategy,
-						this.configMapPropertySourceLocator,
-						this.secretsPropertySourceLocator);
+						configMapPropertySourceLocator, secretsPropertySourceLocator);
 			case EVENT:
 				return new EventBasedConfigurationChangeDetector(this.environment,
 						properties, this.kubernetesClient, strategy,
-						this.configMapPropertySourceLocator,
-						this.secretsPropertySourceLocator);
+						configMapPropertySourceLocator, secretsPropertySourceLocator);
 			}
 			throw new IllegalStateException(
 					"Unsupported configuration reload mode: " + properties.getMode());
@@ -147,6 +146,24 @@ public class ConfigReloadAutoConfiguration {
 			}
 		}
 
+		private static class OnConfigEnabledOrSecretsEnabled extends AnyNestedCondition {
+
+			OnConfigEnabledOrSecretsEnabled() {
+				super(ConfigurationPhase.REGISTER_BEAN);
+			}
+
+			@ConditionalOnBean(ConfigMapPropertySourceLocator.class)
+			static class configEnabled {
+
+			}
+
+			@ConditionalOnBean(SecretsPropertySourceLocator.class)
+			static class secretsEnabled {
+
+			}
+
+		}
+
 	}
 
 }

spring-cloud-kubernetes-config/src/main/java/org/springframework/cloud/kubernetes/config/reload/EventBasedConfigurationChangeDetector.java

@@ -66,7 +66,8 @@ public class EventBasedConfigurationChangeDetector extends ConfigurationChangeDe
 	public void watch() {
 		boolean activated = false;
 
-		if (this.properties.isMonitoringConfigMaps()) {
+		if (this.properties.isMonitoringConfigMaps()
+				&& this.configMapPropertySourceLocator != null) {
 			try {
 				String name = "config-maps-watch";
 				this.watches.put(name, this.kubernetesClient.configMaps()
@@ -91,7 +92,8 @@ public class EventBasedConfigurationChangeDetector extends ConfigurationChangeDe
 			}
 		}
 
-		if (this.properties.isMonitoringSecrets()) {
+		if (this.properties.isMonitoringSecrets()
+				&& this.secretsPropertySourceLocator != null) {
 			try {
 				activated = false;
 				String name = "secrets-watch";

spring-cloud-kubernetes-config/src/main/java/org/springframework/cloud/kubernetes/config/reload/PollingConfigurationChangeDetector.java

@@ -68,7 +68,8 @@ public class PollingConfigurationChangeDetector extends ConfigurationChangeDetec
 	public void executeCycle() {
 
 		boolean changedConfigMap = false;
-		if (this.properties.isMonitoringConfigMaps()) {
+		if (this.properties.isMonitoringConfigMaps()
+				&& this.configMapPropertySourceLocator != null) {
 			List<? extends MapPropertySource> currentConfigMapSources = findPropertySources(
 					ConfigMapPropertySource.class);
 
@@ -81,7 +82,8 @@ public class PollingConfigurationChangeDetector extends ConfigurationChangeDetec
 		}
 
 		boolean changedSecrets = false;
-		if (this.properties.isMonitoringSecrets()) {
+		if (this.properties.isMonitoringSecrets()
+				&& this.secretsPropertySourceLocator != null) {
 			List<MapPropertySource> currentSecretSources = locateMapPropertySources(
 					this.secretsPropertySourceLocator, this.environment);
 			if (currentSecretSources != null && !currentSecretSources.isEmpty()) {

spring-cloud-kubernetes-config/src/test/java/org/springframework/cloud/kubernetes/config/KubernetesConfigConfigurationTest.java

@@ -22,6 +22,8 @@ import org.junit.Test;
 
 import org.springframework.boot.autoconfigure.context.PropertyPlaceholderAutoConfiguration;
 import org.springframework.boot.builder.SpringApplicationBuilder;
+import org.springframework.cloud.autoconfigure.RefreshAutoConfiguration;
+import org.springframework.cloud.kubernetes.config.reload.ConfigReloadAutoConfiguration;
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
@@ -51,13 +53,31 @@ public class KubernetesConfigConfigurationTest {
 	}
 
 	@Test
-	public void kubernetesWhenKubernetesConfigDisabled() throws Exception {
+	public void kubernetesWhenKubernetesConfigAndSecretDisabled() throws Exception {
 		setup("spring.cloud.kubernetes.config.enabled=false",
 				"spring.cloud.kubernetes.secrets.enabled=false");
 		assertThat(this.context.containsBean("configMapPropertySourceLocator")).isFalse();
 		assertThat(this.context.containsBean("secretsPropertySourceLocator")).isFalse();
 	}
 
+	@Test
+	public void kubernetesWhenKubernetesConfigEnabledButSecretDisabled()
+			throws Exception {
+		setup("spring.cloud.kubernetes.config.enabled=true",
+				"spring.cloud.kubernetes.secrets.enabled=false");
+		assertThat(this.context.containsBean("configMapPropertySourceLocator")).isTrue();
+		assertThat(this.context.containsBean("secretsPropertySourceLocator")).isFalse();
+	}
+
+	@Test
+	public void kubernetesWhenKubernetesConfigDisabledButSecretEnabled()
+			throws Exception {
+		setup("spring.cloud.kubernetes.config.enabled=false",
+				"spring.cloud.kubernetes.secrets.enabled=true");
+		assertThat(this.context.containsBean("configMapPropertySourceLocator")).isFalse();
+		assertThat(this.context.containsBean("secretsPropertySourceLocator")).isTrue();
+	}
+
 	@Test
 	public void kubernetesDefaultEnabled() throws Exception {
 		setup("spring.cloud.kubernetes.enabled=true");
@@ -65,10 +85,42 @@ public class KubernetesConfigConfigurationTest {
 		assertThat(this.context.containsBean("secretsPropertySourceLocator")).isTrue();
 	}
 
+	@Test
+	public void kubernetesReloadEnabled() throws Exception {
+		setup("spring.cloud.kubernetes.enabled=true",
+				"spring.cloud.kubernetes.reload.enabled=true");
+		assertThat(this.context.containsBean("configMapPropertySourceLocator")).isTrue();
+		assertThat(this.context.containsBean("secretsPropertySourceLocator")).isTrue();
+		assertThat(this.context.containsBean("propertyChangeWatcher")).isTrue();
+	}
+
+	@Test
+	public void kubernetesReloadEnabledButSecretDisabled() throws Exception {
+		setup("spring.cloud.kubernetes.enabled=true",
+				"spring.cloud.kubernetes.config.enabled=true",
+				"spring.cloud.kubernetes.secrets.enabled=false",
+				"spring.cloud.kubernetes.reload.enabled=true");
+		assertThat(this.context.containsBean("configMapPropertySourceLocator")).isTrue();
+		assertThat(this.context.containsBean("secretsPropertySourceLocator")).isFalse();
+		assertThat(this.context.containsBean("propertyChangeWatcher")).isTrue();
+	}
+
+	@Test
+	public void kubernetesReloadEnabledButSecretAndConfigDisabled() throws Exception {
+		setup("spring.cloud.kubernetes.enabled=true",
+				"spring.cloud.kubernetes.config.enabled=false",
+				"spring.cloud.kubernetes.secrets.enabled=false",
+				"spring.cloud.kubernetes.reload.enabled=true");
+		assertThat(this.context.containsBean("configMapPropertySourceLocator")).isFalse();
+		assertThat(this.context.containsBean("secretsPropertySourceLocator")).isFalse();
+		assertThat(this.context.containsBean("propertyChangeWatcher")).isFalse();
+	}
+
 	private void setup(String... env) {
 		this.context = new SpringApplicationBuilder(
 				PropertyPlaceholderAutoConfiguration.class,
-				KubernetesClientTestConfiguration.class, BootstrapConfiguration.class)
+				KubernetesClientTestConfiguration.class, BootstrapConfiguration.class,
+				ConfigReloadAutoConfiguration.class, RefreshAutoConfiguration.class)
 						.web(org.springframework.boot.WebApplicationType.NONE)
 						.properties(env).run();
 	}