Remove the need for @EnableDiscoveryClient (spring-projects#245)

Enable AutoServiceRegistrationConfiguration by default.

Author: Ryan Baxter

docs/src/main/asciidoc/spring-cloud-commons.adoc

@@ -317,6 +317,9 @@ Commons provides the `@EnableDiscoveryClient` annotation. This looks for impleme
 
 By default, implementations of `DiscoveryClient` will auto-register the local Spring Boot server with the remote discovery server. This can be disabled by setting `autoRegister=false` in `@EnableDiscoveryClient`.
 
+NOTE: The use of `@EnableDiscoveryClient` is no longer required.  It is enough to just have a `DiscoveryClient` implementation
+on the classpath to cause the Spring Boot application to register with the service discovery server.
+
 ==== Health Indicator
 
 Commons creates a Spring Boot `HealthIndicator` that `DiscoveryClient` implementations can participate in by implementing `DiscoveryHealthIndicator`. To disable the composite `HealthIndicator` set `spring.cloud.discovery.client.composite-indicator.enabled=false`. A generic `HealthIndicator` based on `DiscoveryClient` is auto-configured (`DiscoveryClientHealthIndicator). To disable it, set `spring.cloud.discovery.client.health-indicator.enabled=false`. To disable the description field of the `DiscoveryClientHealthIndicator` set `spring.cloud.discovery.client.health-indicator.include-description=false`, otherwise it can bubble up as the `description` of the rolled up `HealthIndicator`.

spring-cloud-commons/src/main/java/org/springframework/cloud/client/discovery/EnableDiscoveryClientImportSelector.java

@@ -21,10 +21,14 @@
 import org.springframework.core.Ordered;
 import org.springframework.core.annotation.AnnotationAttributes;
 import org.springframework.core.annotation.Order;
+import org.springframework.core.env.ConfigurableEnvironment;
+import org.springframework.core.env.Environment;
+import org.springframework.core.env.MapPropertySource;
 import org.springframework.core.type.AnnotationMetadata;
 
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.LinkedHashMap;
 import java.util.List;
 
 /**
@@ -47,6 +51,17 @@ public String[] selectImports(AnnotationMetadata metadata) {
 			List<String> importsList = new ArrayList<>(Arrays.asList(imports));
 			importsList.add("org.springframework.cloud.client.serviceregistry.AutoServiceRegistrationConfiguration");
 			imports = importsList.toArray(new String[0]);
+		} else {
+			Environment env = getEnvironment();
+			if(ConfigurableEnvironment.class.isInstance(env)) {
+				ConfigurableEnvironment configEnv = (ConfigurableEnvironment)env;
+				LinkedHashMap<String, Object> map = new LinkedHashMap<>();
+				map.put("spring.cloud.service-registry.auto-registration.enabled", false);
+				MapPropertySource propertySource = new MapPropertySource(
+						"springCloudDiscoveryClient", map);
+				configEnv.getPropertySources().addLast(propertySource);
+			}
+
 		}
 
 		return imports;

spring-cloud-commons/src/main/java/org/springframework/cloud/client/serviceregistry/AutoServiceRegistrationAutoConfiguration.java

@@ -4,13 +4,17 @@
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Import;
 
 /**
  * @author Spencer Gibb
  */
 @Configuration
-@ConditionalOnBean(AutoServiceRegistrationProperties.class)
+@Import(AutoServiceRegistrationConfiguration.class)
+@ConditionalOnProperty(value = "spring.cloud.service-registry.auto-registration.enabled", matchIfMissing = true)
 public class AutoServiceRegistrationAutoConfiguration {
 
 	@Autowired(required = false)

spring-cloud-commons/src/main/java/org/springframework/cloud/client/serviceregistry/AutoServiceRegistrationConfiguration.java

@@ -1,5 +1,6 @@
 package org.springframework.cloud.client.serviceregistry;
 
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.context.annotation.Configuration;
 
@@ -8,5 +9,6 @@
  */
 @Configuration
 @EnableConfigurationProperties(AutoServiceRegistrationProperties.class)
+@ConditionalOnProperty(value = "spring.cloud.service-registry.auto-registration.enabled", matchIfMissing = true)
 public class AutoServiceRegistrationConfiguration {
 }

spring-cloud-commons/src/main/resources/META-INF/spring.factories

@@ -9,7 +9,8 @@ org.springframework.cloud.client.serviceregistry.ServiceRegistryAutoConfiguratio
 org.springframework.cloud.commons.util.UtilAutoConfiguration,\
 org.springframework.cloud.client.discovery.composite.CompositeDiscoveryClientAutoConfiguration,\
 org.springframework.cloud.client.discovery.simple.SimpleDiscoveryClientAutoConfiguration,\
-org.springframework.cloud.commons.httpclient.HttpClientConfiguration
+org.springframework.cloud.commons.httpclient.HttpClientConfiguration,\
+org.springframework.cloud.client.serviceregistry.AutoServiceRegistrationAutoConfiguration
 
 
 # Environment Post Processors

spring-cloud-commons/src/test/java/org/springframework/cloud/client/discovery/AutoRegisterPropertyFalseTests.java

@@ -0,0 +1,49 @@
+package org.springframework.cloud.client.discovery;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.cloud.client.serviceregistry.AutoServiceRegistration;
+import org.springframework.cloud.client.serviceregistry.AutoServiceRegistrationAutoConfiguration;
+import org.springframework.cloud.client.serviceregistry.AutoServiceRegistrationProperties;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNull;
+
+/**
+ * @author Ryan Baxter
+ */
+@RunWith(SpringRunner.class)
+@SpringBootTest(properties = {"spring.cloud.service-registry.auto-registration.enabled: false"})
+public class AutoRegisterPropertyFalseTests {
+	@Autowired(required = false)
+	AutoServiceRegistrationAutoConfiguration autoConfiguration;
+
+	@Autowired(required = false)
+	AutoServiceRegistration autoServiceRegistration;
+
+	@Autowired(required = false)
+	AutoServiceRegistrationProperties autoServiceRegistrationProperties;
+
+	@Value("${spring.cloud.service-registry.auto-registration.enabled}")
+	Boolean autoRegisterProperty;
+
+	@Test
+	public void veryifyBeans() {
+		assertNull(autoConfiguration);
+		assertNull(autoServiceRegistration);
+		assertNull(autoServiceRegistrationProperties);
+		assertFalse(autoRegisterProperty);
+	}
+
+
+	@EnableAutoConfiguration
+	@Configuration
+	public static class App {
+	}
+}

spring-cloud-commons/src/test/java/org/springframework/cloud/client/discovery/EnableDiscoveryClientAutoRegisterFalseTests.java

@@ -0,0 +1,51 @@
+package org.springframework.cloud.client.discovery;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.cloud.client.serviceregistry.AutoServiceRegistration;
+import org.springframework.cloud.client.serviceregistry.AutoServiceRegistrationAutoConfiguration;
+import org.springframework.cloud.client.serviceregistry.AutoServiceRegistrationProperties;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNull;
+
+/**
+ * @author Ryan Baxter
+ */
+@RunWith(SpringRunner.class)
+@SpringBootTest
+public class EnableDiscoveryClientAutoRegisterFalseTests {
+
+	@Autowired(required = false)
+	AutoServiceRegistrationAutoConfiguration autoConfiguration;
+
+	@Autowired(required = false)
+	AutoServiceRegistration autoServiceRegistration;
+
+	@Autowired(required = false)
+	AutoServiceRegistrationProperties autoServiceRegistrationProperties;
+
+	@Value("${spring.cloud.service-registry.auto-registration.enabled}")
+	Boolean autoRegisterProperty;
+
+	@Test
+	public void veryifyBeans() {
+		assertNull(autoConfiguration);
+		assertNull(autoServiceRegistration);
+		assertNull(autoServiceRegistrationProperties);
+		assertFalse(autoRegisterProperty);
+	}
+
+
+	@EnableAutoConfiguration
+	@Configuration
+	@EnableDiscoveryClient(autoRegister = false)
+	public static class App {
+	}
+}

spring-cloud-commons/src/test/java/org/springframework/cloud/client/discovery/EnableDiscoveryClientImportSelectorTests.java

@@ -9,6 +9,8 @@
 import org.springframework.mock.env.MockEnvironment;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
 import static org.mockito.BDDMockito.given;
 
 /**
@@ -37,13 +39,15 @@ public void setup() {
 	public void autoRegistrationIsEnabled() {
 		configureAnnotation(true);
 		String[] imports = this.importSelector.selectImports(this.annotationMetadata);
+		assertTrue(environment.getProperty("spring.cloud.service-registry.auto-registration.enabled", Boolean.class, true));
 		assertThat(imports).hasSize(1);
 	}
 
 	@Test
 	public void autoRegistrationIsDisabled() {
 		configureAnnotation(false);
 		String[] imports = this.importSelector.selectImports(this.annotationMetadata);
+		assertFalse(environment.getProperty("spring.cloud.service-registry.auto-registration.enabled", Boolean.class));
 		assertThat(imports).isEmpty();
 	}