Add MVC actuator endpoint for heap dumps

Add MVC only endpoint to obtain GZip compressed heap dump files.

See gh-5670

spring-boot-actuator-docs/src/restdoc/java/org/springframework/boot/actuate/hypermedia/EndpointDocumentation.java

@@ -20,12 +20,15 @@ import java.io.File;
 import java.io.FileOutputStream;
 import java.io.PrintWriter;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Comparator;
+import java.util.HashSet;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 
 import groovy.text.Template;
 import groovy.text.TemplateEngine;
@@ -70,6 +73,9 @@ public class EndpointDocumentation {
 
 	static final File LOG_FILE = new File("target/logs/spring.log");
 
+	private static final Set<String> SKIPPED = Collections.<String>unmodifiableSet(
+			new HashSet<String>(Arrays.asList("/docs", "/logfile", "/heapdump")));
+
 	@Autowired
 	private MvcEndpoints mvcEndpoints;
 
@@ -103,28 +109,27 @@ public class EndpointDocumentation {
 
 	@Test
 	public void endpoints() throws Exception {
-
 		final File docs = new File("src/main/asciidoc");
-
 		final Map<String, Object> model = new LinkedHashMap<String, Object>();
 		final List<EndpointDoc> endpoints = new ArrayList<EndpointDoc>();
 		model.put("endpoints", endpoints);
 		for (MvcEndpoint endpoint : getEndpoints()) {
-			final String endpointPath = StringUtils.hasText(endpoint.getPath())
-					? endpoint.getPath() : "/";
-
-			if (!endpointPath.equals("/docs") && !endpointPath.equals("/logfile")) {
+			final String endpointPath = (StringUtils.hasText(endpoint.getPath())
+					? endpoint.getPath() : "/");
+			if (!SKIPPED.contains(endpointPath)) {
 				String output = endpointPath.substring(1);
 				output = output.length() > 0 ? output : "./";
 				this.mockMvc.perform(get(endpointPath).accept(MediaType.APPLICATION_JSON))
 						.andExpect(status().isOk()).andDo(document(output))
 						.andDo(new ResultHandler() {
+
 							@Override
 							public void handle(MvcResult mvcResult) throws Exception {
 								EndpointDoc endpoint = new EndpointDoc(docs,
 										endpointPath);
 								endpoints.add(endpoint);
 							}
+
 						});
 			}
 		}

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

@@ -31,6 +31,7 @@ import org.springframework.boot.actuate.endpoint.mvc.EndpointHandlerMapping;
 import org.springframework.boot.actuate.endpoint.mvc.EndpointHandlerMappingCustomizer;
 import org.springframework.boot.actuate.endpoint.mvc.EnvironmentMvcEndpoint;
 import org.springframework.boot.actuate.endpoint.mvc.HealthMvcEndpoint;
+import org.springframework.boot.actuate.endpoint.mvc.HeapdumpMvcEndpoint;
 import org.springframework.boot.actuate.endpoint.mvc.LogFileMvcEndpoint;
 import org.springframework.boot.actuate.endpoint.mvc.MetricsMvcEndpoint;
 import org.springframework.boot.actuate.endpoint.mvc.MvcEndpoint;
@@ -132,6 +133,13 @@ public class EndpointWebMvcManagementContextConfiguration {
 		return new EnvironmentMvcEndpoint(delegate);
 	}
 
+	@Bean
+	@ConditionalOnMissingBean
+	@ConditionalOnEnabledEndpoint("heapdump")
+	public HeapdumpMvcEndpoint heapdumpMvcEndpoint() {
+		return new HeapdumpMvcEndpoint();
+	}
+
 	@Bean
 	@ConditionalOnBean(HealthEndpoint.class)
 	@ConditionalOnEnabledEndpoint("health")

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

@@ -0,0 +1,233 @@
+/*
+ * 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.endpoint.mvc;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.InputStream;
+import java.lang.management.ManagementFactory;
+import java.lang.management.PlatformManagedObject;
+import java.lang.reflect.Method;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReentrantLock;
+import java.util.zip.GZIPOutputStream;
+
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
+import org.springframework.lang.UsesJava7;
+import org.springframework.util.ClassUtils;
+import org.springframework.util.ReflectionUtils;
+import org.springframework.util.StreamUtils;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestMethod;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.ResponseStatus;
+
+/**
+ * {@link MvcEndpoint} to expose heap dumps.
+ *
+ * @author Lari Hotari
+ * @author Phillip Webb
+ * @since 1.4.0
+ */
+@ConfigurationProperties("endpoints.heapdump")
+@HypermediaDisabled
+public class HeapdumpMvcEndpoint extends AbstractMvcEndpoint implements MvcEndpoint {
+
+	private final long timeout;
+
+	private final Lock lock = new ReentrantLock();
+
+	private HeapDumper heapDumper;
+
+	public HeapdumpMvcEndpoint() {
+		this(TimeUnit.SECONDS.toMillis(10));
+	}
+
+	protected HeapdumpMvcEndpoint(long timeout) {
+		super("/heapdump", true);
+		this.timeout = timeout;
+	}
+
+	@RequestMapping(method = RequestMethod.GET, produces = MediaType.APPLICATION_OCTET_STREAM_VALUE)
+	public void invoke(@RequestParam(defaultValue = "true") boolean live,
+			HttpServletRequest request, HttpServletResponse response)
+					throws IOException, ServletException {
+		if (!isEnabled()) {
+			response.setStatus(HttpStatus.NOT_FOUND.value());
+			return;
+		}
+		try {
+			if (this.lock.tryLock(this.timeout, TimeUnit.MILLISECONDS)) {
+				try {
+					dumpHeap(live, request, response);
+					return;
+				}
+				finally {
+					this.lock.unlock();
+				}
+			}
+		}
+		catch (InterruptedException ex) {
+			// Ignore
+		}
+		response.setStatus(HttpStatus.TOO_MANY_REQUESTS.value());
+	}
+
+	private void dumpHeap(boolean live, HttpServletRequest request,
+			HttpServletResponse response)
+					throws IOException, ServletException, InterruptedException {
+		if (this.heapDumper == null) {
+			this.heapDumper = createHeapDumper();
+		}
+		File file = createTempFile(live);
+		try {
+			this.heapDumper.dumpHeap(file, live);
+			handle(file, request, response);
+		}
+		finally {
+			file.delete();
+		}
+	}
+
+	private File createTempFile(boolean live) throws IOException {
+		String date = new SimpleDateFormat("yyyy-MM-dd-HH-mm").format(new Date());
+		File file = File.createTempFile("heapdump" + date + (live ? "-live" : ""),
+				".hprof");
+		file.delete();
+		return file;
+	}
+
+	/**
+	 * Factory method used to create the {@link HeapDumper}.
+	 * @return the heap dumper to use
+	 * @throws HeapDumperUnavailableException if the heap dumper cannot be created
+	 */
+	protected HeapDumper createHeapDumper() throws HeapDumperUnavailableException {
+		return new HotSpotDiagnosticMXBeanHeapDumper();
+	}
+
+	/**
+	 * Handle the heap dump file and respond. By default this method will return the
+	 * response as a GZip stream.
+	 * @param heapDumpFile the generated dump file
+	 * @param request the HTTP request
+	 * @param response the HTTP response
+	 * @throws ServletException on servlet error
+	 * @throws IOException on IO error
+	 */
+	protected void handle(File heapDumpFile, HttpServletRequest request,
+			HttpServletResponse response) throws ServletException, IOException {
+		response.setContentType("application/octet-stream");
+		response.setHeader("Content-Disposition",
+				"attachment; filename=\"" + (heapDumpFile.getName() + ".gz") + "\"");
+		try {
+			InputStream in = new FileInputStream(heapDumpFile);
+			try {
+				GZIPOutputStream out = new GZIPOutputStream(response.getOutputStream());
+				StreamUtils.copy(in, out);
+				out.finish();
+			}
+			catch (NullPointerException ex) {
+			}
+			finally {
+				try {
+					in.close();
+				}
+				catch (Throwable ex) {
+				}
+			}
+		}
+		catch (FileNotFoundException ex) {
+		}
+	}
+
+	/**
+	 * Strategy interface used to dump the heap to a file.
+	 */
+	protected interface HeapDumper {
+
+		/**
+		 * Dump the current heap to the specified file.
+		 * @param file the file to dump the heap to
+		 * @param live if only <em>live</em> objects (i.e. objects that are reachable from
+		 * others) should be dumped
+		 * @throws IOException on IO error
+		 * @throws InterruptedException on thread interruption
+		 */
+		void dumpHeap(File file, boolean live) throws IOException, InterruptedException;
+
+	}
+
+	/**
+	 * {@link HeapDumper} that uses {@code com.sun.management.HotSpotDiagnosticMXBean}
+	 * available on Oracle and OpenJDK to dump the heap to a file.
+	 */
+	@UsesJava7
+	protected static class HotSpotDiagnosticMXBeanHeapDumper implements HeapDumper {
+
+		private Object diagnosticMXBean;
+
+		private Method dumpHeapMethod;
+
+		@SuppressWarnings("unchecked")
+		protected HotSpotDiagnosticMXBeanHeapDumper() {
+			try {
+				Class<?> diagnosticMXBeanClass = ClassUtils.resolveClassName(
+						"com.sun.management.HotSpotDiagnosticMXBean", null);
+				this.diagnosticMXBean = ManagementFactory.getPlatformMXBean(
+						(Class<PlatformManagedObject>) diagnosticMXBeanClass);
+				this.dumpHeapMethod = ReflectionUtils.findMethod(diagnosticMXBeanClass,
+						"dumpHeap", String.class, Boolean.TYPE);
+			}
+			catch (Throwable ex) {
+				throw new HeapDumperUnavailableException(
+						"Unable to locate HotSpotDiagnosticMXBean", ex);
+			}
+		}
+
+		@Override
+		public void dumpHeap(File file, boolean live) {
+			ReflectionUtils.invokeMethod(this.dumpHeapMethod, this.diagnosticMXBean,
+					file.getAbsolutePath(), live);
+		}
+
+	}
+
+	/**
+	 * Exception to be thrown if the {@link HeapDumper} cannot be created.
+	 */
+	@ResponseStatus(HttpStatus.SERVICE_UNAVAILABLE)
+	protected static class HeapDumperUnavailableException extends RuntimeException {
+
+		public HeapDumperUnavailableException(String message, Throwable cause) {
+			super(message, cause);
+		}
+
+	}
+
+}

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

@@ -429,8 +429,8 @@ public class EndpointWebMvcAutoConfigurationTests {
 		this.applicationContext.register(RootConfig.class, BaseConfiguration.class,
 				ServerPortConfig.class, EndpointWebMvcAutoConfiguration.class);
 		this.applicationContext.refresh();
-		// /health, /metrics, /env, /actuator (/shutdown is disabled by default)
-		assertThat(this.applicationContext.getBeansOfType(MvcEndpoint.class)).hasSize(4);
+		// /health, /metrics, /env, /actuator, /heapdump (/shutdown is disabled by default)
+		assertThat(this.applicationContext.getBeansOfType(MvcEndpoint.class)).hasSize(5);
 	}
 
 	@Test

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

@@ -83,7 +83,7 @@ public class HalBrowserMvcEndpointDisabledIntegrationTests {
 	public void endpointsDoNotHaveLinks() throws Exception {
 		for (MvcEndpoint endpoint : this.mvcEndpoints.getEndpoints()) {
 			String path = endpoint.getPath();
-			if ("/actuator".equals(path)) {
+			if ("/actuator".equals(path) || endpoint instanceof HeapdumpMvcEndpoint) {
 				continue;
 			}
 			path = path.length() > 0 ? path : "/";

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

@@ -122,7 +122,7 @@ public class HalBrowserMvcEndpointVanillaIntegrationTests {
 	@Test
 	public void endpointsEachHaveSelf() throws Exception {
 		Set<String> collections = new HashSet<String>(
-				Arrays.asList("/trace", "/beans", "/dump"));
+				Arrays.asList("/trace", "/beans", "/dump", "/heapdump"));
 		for (MvcEndpoint endpoint : this.mvcEndpoints.getEndpoints()) {
 			String path = endpoint.getPath();
 			if (collections.contains(path)) {

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

@@ -0,0 +1,171 @@
+/*
+ * 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.endpoint.mvc;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.concurrent.TimeUnit;
+import java.util.zip.GZIPInputStream;
+
+import org.fusesource.hawtbuf.ByteArrayInputStream;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.actuate.autoconfigure.EndpointWebMvcAutoConfiguration;
+import org.springframework.boot.actuate.autoconfigure.ManagementServerPropertiesAutoConfiguration;
+import org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration;
+import org.springframework.boot.autoconfigure.web.HttpMessageConvertersAutoConfiguration;
+import org.springframework.boot.autoconfigure.web.WebMvcAutoConfiguration;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Import;
+import org.springframework.test.context.junit4.SpringRunner;
+import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.test.web.servlet.MvcResult;
+import org.springframework.test.web.servlet.setup.MockMvcBuilders;
+import org.springframework.util.FileCopyUtils;
+import org.springframework.web.context.WebApplicationContext;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+/**
+ * Tests for {@link HeapdumpMvcEndpoint}.
+ *
+ * @author Phillip Webb
+ */
+@RunWith(SpringRunner.class)
+@SpringBootTest
+public class HeapdumpMvcEndpointTests {
+
+	@Autowired
+	private WebApplicationContext context;
+
+	private MockMvc mvc;
+
+	@Autowired
+	private TestHeapdumpMvcEndpoint endpoint;
+
+	@Before
+	public void setup() {
+		this.context.getBean(HeapdumpMvcEndpoint.class).setEnabled(true);
+		this.mvc = MockMvcBuilders.webAppContextSetup(this.context).build();
+	}
+
+	@After
+	public void reset() {
+		this.endpoint.reset();
+	}
+
+	@Test
+	public void invokeWhenDisabledShouldReturnNotFoundStatus() throws Exception {
+		this.endpoint.setEnabled(false);
+		this.mvc.perform(get("/heapdump")).andExpect(status().isNotFound());
+	}
+
+	@Test
+	public void invokeWhenNotAvailableShouldReturnServiceUnavailableStatus()
+			throws Exception {
+		this.endpoint.setAvailable(false);
+		this.mvc.perform(get("/heapdump")).andExpect(status().isServiceUnavailable());
+	}
+
+	@Test
+	public void invokeWhenLockedShouldReturnTooManyRequestsStatus() throws Exception {
+		this.endpoint.setLocked(true);
+		this.mvc.perform(get("/heapdump")).andExpect(status().isTooManyRequests());
+	}
+
+	@Test
+	public void invokeShouldReturnGzipContent() throws Exception {
+		MvcResult result = this.mvc.perform(get("/heapdump")).andExpect(status().isOk())
+				.andReturn();
+		byte[] bytes = result.getResponse().getContentAsByteArray();
+		GZIPInputStream stream = new GZIPInputStream(new ByteArrayInputStream(bytes));
+		byte[] uncompressed = FileCopyUtils.copyToByteArray(stream);
+		assertThat(uncompressed).isEqualTo("HEAPDUMP".getBytes());
+	}
+
+	@Import({ JacksonAutoConfiguration.class,
+			HttpMessageConvertersAutoConfiguration.class,
+			EndpointWebMvcAutoConfiguration.class, WebMvcAutoConfiguration.class,
+			ManagementServerPropertiesAutoConfiguration.class })
+	@Configuration
+	public static class TestConfiguration {
+
+		@Bean
+		public HeapdumpMvcEndpoint endpoint() {
+			return new TestHeapdumpMvcEndpoint();
+		}
+
+	}
+
+	private static class TestHeapdumpMvcEndpoint extends HeapdumpMvcEndpoint {
+
+		private boolean available;
+
+		private boolean locked;
+
+		private String heapDump;
+
+		TestHeapdumpMvcEndpoint() {
+			super(TimeUnit.SECONDS.toMillis(1));
+			reset();
+		}
+
+		public void reset() {
+			this.available = true;
+			this.locked = false;
+			this.heapDump = "HEAPDUMP";
+		}
+
+		@Override
+		protected HeapDumper createHeapDumper() {
+			return new HeapDumper() {
+
+				@Override
+				public void dumpHeap(File file, boolean live)
+						throws IOException, InterruptedException {
+					if (!TestHeapdumpMvcEndpoint.this.available) {
+						throw new HeapDumperUnavailableException("Not available", null);
+					}
+					if (TestHeapdumpMvcEndpoint.this.locked) {
+						throw new InterruptedException();
+					}
+					FileCopyUtils.copy(TestHeapdumpMvcEndpoint.this.heapDump.getBytes(),
+							file);
+				}
+
+			};
+		}
+
+		public void setAvailable(boolean available) {
+			this.available = available;
+		}
+
+		public void setLocked(boolean locked) {
+			this.locked = locked;
+		}
+
+	}
+
+}