Add Status endpoint

This commit adds a new `/application/status` endpoint that provides only
the Health's status of an application.

Previously, `/application/health` was returning full health details or
only the status depending on configuration. Those two use cases are now
separate in two endpoints that can be configured, secured and enabled
separately.

Closes gh-9721

Author: snicoll

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

@@ -39,10 +39,12 @@
 import org.springframework.boot.actuate.endpoint.PublicMetrics;
 import org.springframework.boot.actuate.endpoint.RequestMappingEndpoint;
 import org.springframework.boot.actuate.endpoint.ShutdownEndpoint;
+import org.springframework.boot.actuate.endpoint.StatusEndpoint;
 import org.springframework.boot.actuate.endpoint.ThreadDumpEndpoint;
 import org.springframework.boot.actuate.endpoint.TraceEndpoint;
 import org.springframework.boot.actuate.health.HealthAggregator;
 import org.springframework.boot.actuate.health.HealthIndicator;
+import org.springframework.boot.actuate.health.HealthIndicatorFactory;
 import org.springframework.boot.actuate.health.OrderedHealthAggregator;
 import org.springframework.boot.actuate.info.InfoContributor;
 import org.springframework.boot.actuate.trace.InMemoryTraceRepository;
@@ -90,17 +92,6 @@ public EnvironmentEndpoint environmentEndpoint(Environment environment) {
 		return new EnvironmentEndpoint(environment);
 	}
 
-	@Bean
-	@ConditionalOnMissingBean
-	@ConditionalOnEnabledEndpoint
-	public HealthEndpoint healthEndpoint(
-			ObjectProvider<HealthAggregator> healthAggregator,
-			ObjectProvider<Map<String, HealthIndicator>> healthIndicators) {
-		return new HealthEndpoint(
-				healthAggregator.getIfAvailable(() -> new OrderedHealthAggregator()),
-				healthIndicators.getIfAvailable(Collections::emptyMap));
-	}
-
 	@Bean
 	@ConditionalOnMissingBean
 	@ConditionalOnEnabledEndpoint
@@ -182,6 +173,34 @@ public AuditEventsEndpoint auditEventsEndpoint(
 		return new AuditEventsEndpoint(auditEventRepository);
 	}
 
+	@Configuration
+	static class HealthEndpointConfiguration {
+
+		private final HealthIndicator healthIndicator;
+
+		HealthEndpointConfiguration(ObjectProvider<HealthAggregator> healthAggregator,
+				ObjectProvider<Map<String, HealthIndicator>> healthIndicators) {
+			this.healthIndicator = new HealthIndicatorFactory().createHealthIndicator(
+					healthAggregator.getIfAvailable(OrderedHealthAggregator::new),
+					healthIndicators.getIfAvailable(Collections::emptyMap));
+		}
+
+		@Bean
+		@ConditionalOnMissingBean
+		@ConditionalOnEnabledEndpoint
+		public HealthEndpoint healthEndpoint() {
+			return new HealthEndpoint(this.healthIndicator);
+		}
+
+		@Bean
+		@ConditionalOnMissingBean
+		@ConditionalOnEnabledEndpoint
+		public StatusEndpoint statusEndpoint() {
+			return new StatusEndpoint(this.healthIndicator);
+		}
+
+	}
+
 	@Configuration
 	@ConditionalOnBean(Flyway.class)
 	@ConditionalOnClass(Flyway.class)

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/autoconfigure/endpoint/web/WebEndpointManagementContextConfiguration.java

@@ -20,10 +20,13 @@
 import org.springframework.boot.actuate.autoconfigure.endpoint.ConditionalOnEnabledEndpoint;
 import org.springframework.boot.actuate.endpoint.AuditEventsEndpoint;
 import org.springframework.boot.actuate.endpoint.HealthEndpoint;
+import org.springframework.boot.actuate.endpoint.StatusEndpoint;
 import org.springframework.boot.actuate.endpoint.web.AuditEventsWebEndpointExtension;
+import org.springframework.boot.actuate.endpoint.web.HealthStatusHttpMapper;
 import org.springframework.boot.actuate.endpoint.web.HealthWebEndpointExtension;
 import org.springframework.boot.actuate.endpoint.web.HeapDumpWebEndpoint;
 import org.springframework.boot.actuate.endpoint.web.LogFileWebEndpoint;
+import org.springframework.boot.actuate.endpoint.web.StatusWebEndpointExtension;
 import org.springframework.boot.autoconfigure.condition.ConditionMessage;
 import org.springframework.boot.autoconfigure.condition.ConditionOutcome;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
@@ -61,12 +64,27 @@ public HeapDumpWebEndpoint heapDumpWebEndpoint() {
 	@ConditionalOnBean(value = HealthEndpoint.class, search = SearchStrategy.CURRENT)
 	public HealthWebEndpointExtension healthWebEndpointExtension(HealthEndpoint delegate,
 			HealthWebEndpointExtensionProperties extensionProperties) {
-		HealthWebEndpointExtension webExtension = new HealthWebEndpointExtension(
-				delegate);
+		return new HealthWebEndpointExtension(delegate,
+				createHealthStatusHttpMapper(extensionProperties));
+	}
+
+	@Bean
+	@ConditionalOnMissingBean
+	@ConditionalOnEnabledEndpoint
+	@ConditionalOnBean(value = StatusEndpoint.class, search = SearchStrategy.CURRENT)
+	public StatusWebEndpointExtension statusWebEndpointExtension(StatusEndpoint delegate,
+			HealthWebEndpointExtensionProperties extensionProperties) {
+		return new StatusWebEndpointExtension(delegate,
+				createHealthStatusHttpMapper(extensionProperties));
+	}
+
+	private HealthStatusHttpMapper createHealthStatusHttpMapper(
+			HealthWebEndpointExtensionProperties extensionProperties) {
+		HealthStatusHttpMapper statusHttpMapper = new HealthStatusHttpMapper();
 		if (extensionProperties.getMapping() != null) {
-			webExtension.addStatusMapping(extensionProperties.getMapping());
+			statusHttpMapper.addStatusMapping(extensionProperties.getMapping());
 		}
-		return webExtension;
+		return statusHttpMapper;
 	}
 
 	@Bean

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

@@ -16,15 +16,10 @@
 
 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.endpoint.Endpoint;
 import org.springframework.boot.endpoint.ReadOperation;
-import org.springframework.util.Assert;
 
 /**
  * {@link Endpoint} to expose application health.
@@ -40,18 +35,9 @@ public class HealthEndpoint {
 
 	/**
 	 * Create a new {@link HealthEndpoint} instance.
-	 * @param healthAggregator the health aggregator
-	 * @param healthIndicators the health indicators
+	 * @param healthIndicator the health indicator
 	 */
-	public HealthEndpoint(HealthAggregator healthAggregator,
-			Map<String, HealthIndicator> healthIndicators) {
-		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());
-		}
+	public HealthEndpoint(HealthIndicator healthIndicator) {
 		this.healthIndicator = healthIndicator;
 	}
 
@@ -60,17 +46,4 @@ public Health health() {
 		return this.healthIndicator.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/endpoint/StatusEndpoint.java

@@ -0,0 +1,49 @@
+/*
+ * Copyright 2012-2017 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.endpoint;
+
+import org.springframework.boot.actuate.health.Health;
+import org.springframework.boot.actuate.health.HealthIndicator;
+import org.springframework.boot.actuate.health.Status;
+import org.springframework.boot.endpoint.Endpoint;
+import org.springframework.boot.endpoint.ReadOperation;
+
+/**
+ * {@link Endpoint} to expose application {@link Status}.
+ *
+ * @author Stephane Nicoll
+ * @since 2.0.0
+ */
+@Endpoint(id = "status")
+public class StatusEndpoint {
+
+	private final HealthIndicator healthIndicator;
+
+	/**
+	 * Create a new {@link StatusEndpoint} instance.
+	 * @param healthIndicator the health indicator
+	 */
+	public StatusEndpoint(HealthIndicator healthIndicator) {
+		this.healthIndicator = healthIndicator;
+	}
+
+	@ReadOperation
+	public Health health() {
+		return Health.status(this.healthIndicator.health().getStatus()).build();
+	}
+
+}

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

@@ -0,0 +1,127 @@
+/*
+ * Copyright 2012-2017 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.endpoint.web;
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.springframework.boot.actuate.health.Status;
+import org.springframework.http.HttpStatus;
+import org.springframework.util.Assert;
+
+/**
+ * Map a {@link Status} to an HTTP status code.
+ *
+ * @author Stephane Nicoll
+ * @since 2.0.0
+ */
+public class HealthStatusHttpMapper {
+
+	private Map<String, Integer> statusMapping = new HashMap<>();
+
+	/**
+	 * Create a new instance.
+	 */
+	public HealthStatusHttpMapper() {
+		setupDefaultStatusMapping();
+	}
+
+	private void setupDefaultStatusMapping() {
+		addStatusMapping(Status.DOWN, 503);
+		addStatusMapping(Status.OUT_OF_SERVICE, 503);
+	}
+
+	/**
+	 * Set specific status mappings.
+	 * @param statusMapping a map of status code to {@link HttpStatus}
+	 */
+	public void setStatusMapping(Map<String, Integer> statusMapping) {
+		Assert.notNull(statusMapping, "StatusMapping must not be null");
+		this.statusMapping = new HashMap<>(statusMapping);
+	}
+
+	/**
+	 * Add specific status mappings to the existing set.
+	 * @param statusMapping a map of status code to {@link HttpStatus}
+	 */
+	public void addStatusMapping(Map<String, Integer> statusMapping) {
+		Assert.notNull(statusMapping, "StatusMapping must not be null");
+		this.statusMapping.putAll(statusMapping);
+	}
+
+	/**
+	 * Add a status mapping to the existing set.
+	 * @param status the status to map
+	 * @param httpStatus the http status
+	 */
+	public void addStatusMapping(Status status, Integer httpStatus) {
+		Assert.notNull(status, "Status must not be null");
+		Assert.notNull(httpStatus, "HttpStatus must not be null");
+		addStatusMapping(status.getCode(), httpStatus);
+	}
+
+	/**
+	 * Add a status mapping to the existing set.
+	 * @param statusCode the status code to map
+	 * @param httpStatus the http status
+	 */
+	public void addStatusMapping(String statusCode, Integer httpStatus) {
+		Assert.notNull(statusCode, "StatusCode must not be null");
+		Assert.notNull(httpStatus, "HttpStatus must not be null");
+		this.statusMapping.put(statusCode, httpStatus);
+	}
+
+	/**
+	 * Return an immutable view of the status mapping.
+	 * @return the http status codes mapped by status name
+	 */
+	public Map<String, Integer> getStatusMapping() {
+		return Collections.unmodifiableMap(this.statusMapping);
+	}
+
+	/**
+	 * Map the specified {@link Status} to an HTTP status code.
+	 * @param status the health {@link Status}
+	 * @return the corresponding HTTP status code
+	 */
+	public int mapStatus(Status status) {
+		String code = getUniformValue(status.getCode());
+		if (code != null) {
+			return this.statusMapping.keySet().stream()
+					.filter((key) -> code.equals(getUniformValue(key)))
+					.map(this.statusMapping::get).findFirst().orElse(200);
+		}
+		return 200;
+	}
+
+
+
+	private String getUniformValue(String code) {
+		if (code == null) {
+			return null;
+		}
+		StringBuilder builder = new StringBuilder();
+		for (char ch : code.toCharArray()) {
+			if (Character.isAlphabetic(ch) || Character.isDigit(ch)) {
+				builder.append(Character.toLowerCase(ch));
+			}
+		}
+		return builder.toString();
+	}
+
+}