Introduce HealthIndicatorRegistry

This commit introduces HealthIndicatorRegistry which handles registration of HealthIndicator instances. Registering new HealthIndicator instances is now possible in runtime.

Author: vpavic

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/autoconfigure/EndpointAutoConfiguration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2015 the original author or authors.
+ * Copyright 2012-2016 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.
@@ -19,7 +19,6 @@
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
-import java.util.HashMap;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
@@ -46,8 +45,9 @@
 import org.springframework.boot.actuate.endpoint.RequestMappingEndpoint;
 import org.springframework.boot.actuate.endpoint.ShutdownEndpoint;
 import org.springframework.boot.actuate.endpoint.TraceEndpoint;
+import org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistry;
 import org.springframework.boot.actuate.health.HealthAggregator;
-import org.springframework.boot.actuate.health.HealthIndicator;
+import org.springframework.boot.actuate.health.HealthIndicatorRegistry;
 import org.springframework.boot.actuate.health.OrderedHealthAggregator;
 import org.springframework.boot.actuate.trace.InMemoryTraceRepository;
 import org.springframework.boot.actuate.trace.TraceRepository;
@@ -81,6 +81,7 @@
  * @author Christian Dupuis
  * @author Stephane Nicoll
  * @author Eddú Meléndez
+ * @author Vedran Pavic
  */
 @Configuration
 @AutoConfigureAfter({ FlywayAutoConfiguration.class, LiquibaseAutoConfiguration.class })
@@ -94,7 +95,7 @@ public class EndpointAutoConfiguration {
 	private HealthAggregator healthAggregator = new OrderedHealthAggregator();
 
 	@Autowired(required = false)
-	private Map<String, HealthIndicator> healthIndicators = new HashMap<String, HealthIndicator>();
+	private HealthIndicatorRegistry healthIndicatorRegistry = new DefaultHealthIndicatorRegistry();
 
 	@Autowired(required = false)
 	private Collection<PublicMetrics> publicMetrics;
@@ -111,7 +112,7 @@ public EnvironmentEndpoint environmentEndpoint() {
 	@Bean
 	@ConditionalOnMissingBean
 	public HealthEndpoint healthEndpoint() {
-		return new HealthEndpoint(this.healthAggregator, this.healthIndicators);
+		return new HealthEndpoint(this.healthAggregator, this.healthIndicatorRegistry);
 	}
 
 	@Bean

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/autoconfigure/HealthIndicatorAutoConfiguration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2015 the original author or authors.
+ * Copyright 2012-2016 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.
@@ -33,12 +33,14 @@
 import org.springframework.boot.actuate.health.CassandraHealthIndicator;
 import org.springframework.boot.actuate.health.CompositeHealthIndicator;
 import org.springframework.boot.actuate.health.DataSourceHealthIndicator;
+import org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistry;
 import org.springframework.boot.actuate.health.DiskSpaceHealthIndicator;
 import org.springframework.boot.actuate.health.DiskSpaceHealthIndicatorProperties;
 import org.springframework.boot.actuate.health.ElasticsearchHealthIndicator;
 import org.springframework.boot.actuate.health.ElasticsearchHealthIndicatorProperties;
 import org.springframework.boot.actuate.health.HealthAggregator;
 import org.springframework.boot.actuate.health.HealthIndicator;
+import org.springframework.boot.actuate.health.HealthIndicatorRegistry;
 import org.springframework.boot.actuate.health.JmsHealthIndicator;
 import org.springframework.boot.actuate.health.MailHealthIndicator;
 import org.springframework.boot.actuate.health.MongoHealthIndicator;
@@ -84,6 +86,7 @@
  * @author Stephane Nicoll
  * @author Phillip Webb
  * @author Tommy Ludwig
+ * @author Vedran Pavic
  * @since 1.1.0
  */
 @Configuration
@@ -110,6 +113,19 @@ public OrderedHealthAggregator healthAggregator() {
 		return healthAggregator;
 	}
 
+	@Bean
+	@ConditionalOnMissingBean(HealthIndicatorRegistry.class)
+	public HealthIndicatorRegistry healthIndicatorRegistry(
+			Map<String, HealthIndicator> healthIndicators) {
+		HealthIndicatorRegistry registry = new DefaultHealthIndicatorRegistry();
+		for (Map.Entry<String, HealthIndicator> entry : healthIndicators.entrySet()) {
+			String name = entry.getKey();
+			int index = name.toLowerCase().indexOf("healthindicator");
+			registry.register(index > 0 ? name.substring(0, index) : name, entry.getValue());
+		}
+		return registry;
+	}
+
 	@Bean
 	@ConditionalOnMissingBean(HealthIndicator.class)
 	public ApplicationHealthIndicator applicationHealthIndicator() {

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2015 the original author or authors.
+ * Copyright 2012-2016 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.
@@ -16,12 +16,11 @@
 
 package org.springframework.boot.actuate.endpoint;
 
-import java.util.Map;
-
 import org.springframework.boot.actuate.health.CompositeHealthIndicator;
 import org.springframework.boot.actuate.health.Health;
 import org.springframework.boot.actuate.health.HealthAggregator;
 import org.springframework.boot.actuate.health.HealthIndicator;
+import org.springframework.boot.actuate.health.HealthIndicatorRegistry;
 import org.springframework.boot.context.properties.ConfigurationProperties;
 import org.springframework.util.Assert;
 
@@ -31,11 +30,13 @@
  * @author Dave Syer
  * @author Christian Dupuis
  * @author Andy Wilkinson
+ * @author Vedran Pavic
  */
 @ConfigurationProperties(prefix = "endpoints.health", ignoreUnknownFields = true)
 public class HealthEndpoint extends AbstractEndpoint<Health> {
 
-	private final HealthIndicator healthIndicator;
+	private final HealthAggregator healthAggregator;
+	private final HealthIndicatorRegistry healthIndicatorRegistry;
 
 	/**
 	 * Time to live for cached result, in milliseconds.
@@ -45,19 +46,16 @@ public class HealthEndpoint extends AbstractEndpoint<Health> {
 	/**
 	 * Create a new {@link HealthIndicator} instance.
 	 * @param healthAggregator the health aggregator
-	 * @param healthIndicators the health indicators
+	 * @param healthIndicatorRegistry the health indicator registry
 	 */
 	public HealthEndpoint(HealthAggregator healthAggregator,
-			Map<String, HealthIndicator> healthIndicators) {
+			HealthIndicatorRegistry healthIndicatorRegistry) {
 		super("health", false);
 		Assert.notNull(healthAggregator, "HealthAggregator must not be null");
-		Assert.notNull(healthIndicators, "HealthIndicators must not be null");
-		CompositeHealthIndicator healthIndicator = new CompositeHealthIndicator(
-				healthAggregator);
-		for (Map.Entry<String, HealthIndicator> entry : healthIndicators.entrySet()) {
-			healthIndicator.addHealthIndicator(getKey(entry.getKey()), entry.getValue());
-		}
-		this.healthIndicator = healthIndicator;
+		Assert.notNull(healthIndicatorRegistry,
+				"healthIndicatorRegistry must not be null");
+		this.healthAggregator = healthAggregator;
+		this.healthIndicatorRegistry = healthIndicatorRegistry;
 	}
 
 	/**
@@ -78,19 +76,9 @@ public void setTimeToLive(long ttl) {
 	 */
 	@Override
 	public Health invoke() {
-		return this.healthIndicator.health();
+		HealthIndicator indicator = new CompositeHealthIndicator(
+				this.healthAggregator, this.healthIndicatorRegistry.getAll());
+		return indicator.health();
 	}
 
-	/**
-	 * Turns the bean name into a key that can be used in the map of health information.
-	 * @param name the bean name
-	 * @return the key
-	 */
-	private String getKey(String name) {
-		int index = name.toLowerCase().indexOf("healthindicator");
-		if (index > 0) {
-			return name.substring(0, index);
-		}
-		return name;
-	}
 }

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/health/DefaultHealthIndicatorRegistry.java

@@ -0,0 +1,62 @@
+/*
+ * Copyright 2012-2016 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
+ *
+ *      http://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.boot.actuate.health;
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+
+import org.springframework.util.Assert;
+
+/**
+ * Default implementation of {@link HealthIndicatorRegistry}.
+ *
+ * @author Vedran Pavic
+ */
+public class DefaultHealthIndicatorRegistry implements HealthIndicatorRegistry {
+
+	private final ConcurrentMap<String, HealthIndicator> healthIndicators =
+			new ConcurrentHashMap<String, HealthIndicator>();
+
+	@Override
+	public void register(String name, HealthIndicator healthIndicator) {
+		Assert.notNull(healthIndicator, "HealthIndicator must not be null");
+		if (this.healthIndicators.putIfAbsent(name, healthIndicator) != null) {
+			throw new IllegalStateException(
+					"HealthIndicator with name '" + name + "' already registered");
+		}
+	}
+
+	@Override
+	public HealthIndicator unregister(String name) {
+		return this.healthIndicators.remove(name);
+	}
+
+	@Override
+	public HealthIndicator get(String name) {
+		return this.healthIndicators.get(name);
+	}
+
+	@Override
+	public Map<String, HealthIndicator> getAll() {
+		return Collections.unmodifiableMap(
+				new HashMap<String, HealthIndicator>(this.healthIndicators));
+	}
+
+}

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/health/HealthIndicatorRegistry.java

@@ -0,0 +1,65 @@
+/*
+ * Copyright 2012-2016 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
+ *
+ *      http://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.boot.actuate.health;
+
+import java.util.Map;
+
+/**
+ * A registry of {@link HealthIndicator}s.
+ * <p>
+ * Implementations <strong>must</strong> be thread-safe.
+ *
+ * @author Andy Wilkinson
+ * @author Vedran Pavic
+ */
+public interface HealthIndicatorRegistry {
+
+	/**
+	 * Registers the given {@code healthIndicator}, associating it with the given
+	 * {@code name}.
+	 * @param name the name of the indicator
+	 * @param healthIndicator the indicator
+	 * @throws IllegalStateException if an indicator with the given {@code name} is
+	 * already registered.
+	 */
+	void register(String name, HealthIndicator healthIndicator);
+
+	/**
+	 * Unregisters the {@code HealthIndicator} previously registered with the given
+	 * {@code name}.
+	 * @param name the name of the indicator
+	 * @return the unregistered indicator, or {@code null} if no indicator was found in
+	 * the registry for the given {@code name}.
+	 */
+	HealthIndicator unregister(String name);
+
+	/**
+	 * Returns the health indicator registered with the given {@code name}.
+	 * @param name the name of the indicator
+	 * @return the health indicator, or {@code null} if no indicator was registered with
+	 * the given {@code name}.
+	 */
+	HealthIndicator get(String name);
+
+	/**
+	 * Returns a snapshot of the registered health indicators and their names. The
+	 * contents of the map do not reflect subsequent changes to the registry.
+	 * @return the snapshot of registered health indicators
+	 */
+	Map<String, HealthIndicator> getAll();
+
+}

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2015 the original author or authors.
+ * Copyright 2012-2016 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.
@@ -21,8 +21,10 @@
 
 import org.springframework.boot.actuate.endpoint.mvc.HealthMvcEndpoint;
 import org.springframework.boot.actuate.health.AbstractHealthIndicator;
+import org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistry;
 import org.springframework.boot.actuate.health.Health;
 import org.springframework.boot.actuate.health.Health.Builder;
+import org.springframework.boot.actuate.health.HealthIndicatorRegistry;
 import org.springframework.boot.actuate.health.Status;
 import org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration;
 import org.springframework.boot.autoconfigure.security.SecurityAutoConfiguration;
@@ -42,6 +44,7 @@
  *
  * @author Dave Syer
  * @author Andy Wilkinson
+ * @author Vedran Pavic
  */
 public class HealthMvcEndpointAutoConfigurationTests {
 
@@ -94,6 +97,13 @@ public TestHealthIndicator testHealthIndicator() {
 			return new TestHealthIndicator();
 		}
 
+		@Bean
+		public HealthIndicatorRegistry healthIndicatorRegistry() {
+			DefaultHealthIndicatorRegistry registry = new DefaultHealthIndicatorRegistry();
+			registry.register("test", testHealthIndicator());
+			return registry;
+		}
+
 	}
 
 	static class TestHealthIndicator extends AbstractHealthIndicator {