Provide a way to opt-in to endpoint enablement

Update AbstractEndpoint so that the `enable` property is optional and
when it not specified the `endpoints.enabled` property will be used.

This allows users to switch the way that endpoints are enabled. Rather
than opting-out specific endpoint enablement the `endpoints.enabled`
property can be set to `false` and specific endpoints can be opted-in.

Fixes gh-2102

Author: philwebb

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/endpoint/AbstractEndpoint.java

@@ -19,13 +19,20 @@
 import javax.validation.constraints.NotNull;
 import javax.validation.constraints.Pattern;
 
+import org.springframework.context.EnvironmentAware;
+import org.springframework.core.env.Environment;
+
 /**
  * Abstract base for {@link Endpoint} implementations.
  *
  * @author Phillip Webb
  * @author Christian Dupuis
  */
-public abstract class AbstractEndpoint<T> implements Endpoint<T> {
+public abstract class AbstractEndpoint<T> implements Endpoint<T>, EnvironmentAware {
+
+	private static final String ENDPOINTS_ENABLED_PROPERTY = "endpoints.enabled";
+
+	private Environment environment;
 
 	/**
 	 * Endpoint identifier. With HTTP monitoring the identifier of the endpoint is mapped
@@ -36,25 +43,52 @@ public abstract class AbstractEndpoint<T> implements Endpoint<T> {
 	private String id;
 
 	/**
-	 * Enable security on the endpoint.
+	 * Mark if the endpoint exposes sensitive information.
 	 */
 	private boolean sensitive;
 
 	/**
 	 * Enable the endpoint.
 	 */
-	private boolean enabled = true;
+	private Boolean enabled;
 
+	/**
+	 * Create a new sensitive endpoint instance. The enpoint will enabled flag will be
+	 * based on the spring {@link Environment} unless explicitly set.
+	 * @param id the endpoint ID
+	 */
 	public AbstractEndpoint(String id) {
-		this(id, true, true);
+		this(id, true);
+	}
+
+	/**
+	 * Create a new endpoint instance. The enpoint will enabled flag will be based on the
+	 * spring {@link Environment} unless explicitly set.
+	 * @param id the endpoint ID
+	 * @param sensitive if the endpoint is sensitive
+	 */
+	public AbstractEndpoint(String id, boolean sensitive) {
+		this.id = id;
+		this.sensitive = sensitive;
 	}
 
+	/**
+	 * Create a new endpoint instance.
+	 * @param id the endpoint ID
+	 * @param sensitive if the endpoint is sensitive
+	 * @param enabled if the endpoint is enabled or not.
+	 */
 	public AbstractEndpoint(String id, boolean sensitive, boolean enabled) {
 		this.id = id;
 		this.sensitive = sensitive;
 		this.enabled = enabled;
 	}
 
+	@Override
+	public void setEnvironment(Environment environment) {
+		this.environment = environment;
+	}
+
 	@Override
 	public String getId() {
 		return this.id;
@@ -66,10 +100,16 @@ public void setId(String id) {
 
 	@Override
 	public boolean isEnabled() {
-		return this.enabled;
+		if (this.enabled != null) {
+			return this.enabled;
+		}
+		if (this.environment != null) {
+			this.environment.getProperty(ENDPOINTS_ENABLED_PROPERTY, Boolean.class, true);
+		}
+		return true;
 	}
 
-	public void setEnabled(boolean enabled) {
+	public void setEnabled(Boolean enabled) {
 		this.enabled = enabled;
 	}
 

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/endpoint/Endpoint.java

@@ -18,11 +18,13 @@
 
 /**
  * An endpoint that can be used to expose useful information to operations. Usually
- * exposed via Spring MVC but could also be exposed using some other technique.
+ * exposed via Spring MVC but could also be exposed using some other technique. Consider
+ * extending {@link AbstractEndpoint} if you are developing your own endpoint.
  *
  * @author Phillip Webb
  * @author Dave Syer
  * @author Christian Dupuis
+ * @see AbstractEndpoint
  */
 public interface Endpoint<T> {
 

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/endpoint/HealthEndpoint.java

@@ -47,7 +47,7 @@ public class HealthEndpoint extends AbstractEndpoint<Health> {
 	 */
 	public HealthEndpoint(HealthAggregator healthAggregator,
 			Map<String, HealthIndicator> healthIndicators) {
-		super("health", false, true);
+		super("health", false);
 		Assert.notNull(healthAggregator, "HealthAggregator must not be null");
 		Assert.notNull(healthIndicators, "HealthIndicators must not be null");
 		CompositeHealthIndicator healthIndicator = new CompositeHealthIndicator(

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/endpoint/InfoEndpoint.java

@@ -39,7 +39,7 @@ public class InfoEndpoint extends AbstractEndpoint<Map<String, Object>> {
 	 * @param info the info to expose
 	 */
 	public InfoEndpoint(Map<String, ? extends Object> info) {
-		super("info", false, true);
+		super("info", false);
 		Assert.notNull(info, "Info must not be null");
 		this.info = info;
 	}

spring-boot-actuator/src/main/resources/META-INF/additional-spring-configuration-metadata.json

@@ -1,4 +1,10 @@
 {"properties": [
+  {
+    "name": "endpoints.enabled",
+    "type": "java.lang.Boolean",
+    "description": "Enable endpoints.",
+    "defaultValue": true
+  },
   {
     "name": "endpoints.configprops.keys-to-sanitize",
     "type": "java.lang.String",

spring-boot-actuator/src/test/java/org/springframework/boot/actuate/autoconfigure/EndpointMBeanExportAutoConfigurationTests.java

@@ -202,7 +202,7 @@ public static class TestConfiguration {
 	protected static class ManagedEndpoint extends AbstractEndpoint<Boolean> {
 
 		public ManagedEndpoint() {
-			super("managed", true, true);
+			super("managed", true);
 		}
 
 		@Override
@@ -224,7 +224,7 @@ public Endpoint<Boolean> nested() {
 		class Nested extends AbstractEndpoint<Boolean> {
 
 			public Nested() {
-				super("managed", true, true);
+				super("managed", true);
 			}
 
 			@Override

spring-boot-actuator/src/test/java/org/springframework/boot/actuate/endpoint/AbstractEndpointTests.java

@@ -102,6 +102,37 @@ Collections.<String, Object> singletonMap(this.property + ".sensitive",
 		assertThat(getEndpointBean().isSensitive(), equalTo(!this.sensitive));
 	}
 
+	@Test
+	public void isEnabledByDefault() throws Exception {
+		assertThat(getEndpointBean().isEnabled(), equalTo(true));
+	}
+
+	@Test
+	public void isEnabledFallbackToEnvironment() throws Exception {
+		this.context = new AnnotationConfigApplicationContext();
+		PropertySource<?> propertySource = new MapPropertySource("test",
+				Collections.<String, Object> singletonMap(this.property + ".enabled",
+						false));
+		this.context.getEnvironment().getPropertySources().addFirst(propertySource);
+		this.context.register(this.configClass);
+		this.context.refresh();
+		assertThat(getEndpointBean().isEnabled(), equalTo(false));
+	}
+
+	@Test
+	@SuppressWarnings("rawtypes")
+	public void isExplicitlyEnabled() throws Exception {
+		this.context = new AnnotationConfigApplicationContext();
+		PropertySource<?> propertySource = new MapPropertySource("test",
+				Collections.<String, Object> singletonMap(this.property + ".enabled",
+						false));
+		this.context.getEnvironment().getPropertySources().addFirst(propertySource);
+		this.context.register(this.configClass);
+		this.context.refresh();
+		((AbstractEndpoint) getEndpointBean()).setEnabled(true);
+		assertThat(getEndpointBean().isEnabled(), equalTo(true));
+	}
+
 	@SuppressWarnings("unchecked")
 	protected T getEndpointBean() {
 		return (T) this.context.getBean(this.type);

spring-boot-actuator/src/test/java/org/springframework/boot/actuate/endpoint/ShutdownEndpointTests.java

@@ -26,6 +26,7 @@
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.event.ContextClosedEvent;
 
+import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.startsWith;
 import static org.junit.Assert.assertThat;
 import static org.junit.Assert.assertTrue;
@@ -43,6 +44,12 @@ public ShutdownEndpointTests() {
 				"endpoints.shutdown");
 	}
 
+	@Override
+	public void isEnabledByDefault() throws Exception {
+		// Shutdown is dangerous so is disabled by default
+		assertThat(getEndpointBean().isEnabled(), equalTo(false));
+	}
+
 	@Test
 	public void invoke() throws Exception {
 		CountDownLatch latch = this.context.getBean(Config.class).latch;
@@ -61,7 +68,6 @@ public static class Config {
 		@Bean
 		public ShutdownEndpoint endpoint() {
 			ShutdownEndpoint endpoint = new ShutdownEndpoint();
-			endpoint.setEnabled(true);
 			return endpoint;
 		}
 

spring-boot-docs/src/main/asciidoc/production-ready-features.adoc

@@ -135,6 +135,16 @@ of the `beans` endpoint and also enables `shutdown`.
 NOTE: The prefix ‟`endpoints` + `.` + `name`” is used to uniquely identify the endpoint
 that is being configured.
 
+By default, all endpoints except for `shutdown` are enabled. If you prefer to
+specifically "`opt-in`" endpoint enablement you can use the `endpoints.enabled` property.
+For example, the following will disable _all_ endpoints except for `info`:
+
+[source,properties,indent=0]
+----
+	endpoints.enabled=false
+	endpoints.info.enabled=true
+----
+
 
 
 [[production-ready-health]]
@@ -394,6 +404,10 @@ in your `application.properties`:
 	management.security.role=SUPERUSER
 ----
 
+TIP: If you don't use Spring Security and your HTTP endpoints are exposed publicly,
+you should carefully consider which endpoints you enable. See
+<<production-ready-customizing-endpoints>> for details of how you can set
+`endpoints.enabled` to `false` then "`opt-in`" only specific endpoints.
 
 
 [[production-ready-customizing-management-server-context-path]]