Add HealthIndicator that checks free disk space

See gh-1297

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

+/*
+ * Copyright 2014 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.io.File;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Component;
+import org.springframework.util.Assert;
+
+/**
+ * A {@link HealthIndicator} that checks for available disk space.
+ *
+ * @author Mattias Severson
+ * @since 1.2.0
+ */
+@Component
+public class DiskSpaceHealthIndicator extends AbstractHealthIndicator {
+	private static Log logger = LogFactory.getLog(DiskSpaceHealthIndicator.class);
+
+	private final File path;
+	private final long thresholdBytes;
+
+	/**
+	 * Constructor.
+	 * @param path The path to a directory for checking available disk space. The
+	 *                application must have read access to this path. Additionally, the
+	 *                {@link java.lang.SecurityManager#checkRead(String)} will be called
+	 *                if a security manager is used.
+	 *                By default, it uses the system property {@code user.dir}, i.e. the
+	 *                current directory when the JVM was started.
+	 * @param thresholdBytes The threshold (in Bytes) of remaining disk space that will
+	 *                          trigger this health indicator when exceeded.
+	 *                          Default value is 10485760 Bytes (10 MB).
+	 */
+	@Autowired
+	public DiskSpaceHealthIndicator(@Value("${health.path?:${user.dir}}") String path,
+									@Value("${health.threshold.bytes:10485760}") long thresholdBytes) {
+		this.path = new File(path);
+		this.thresholdBytes = thresholdBytes;
+		verifyPathIsAccessible(this.path);
+		Assert.isTrue(thresholdBytes >= 0, "thresholdBytes must be greater than 0");
+	}
+
+	@Override
+	protected void doHealthCheck(Health.Builder builder) throws Exception {
+		long diskFreeInBytes = this.path.getFreeSpace();
+		if (diskFreeInBytes >= this.thresholdBytes) {
+			builder.up();
+		} else {
+			logger.warn(String.format("Free disk space threshold exceeded. " +
+							"Available: %d bytes (threshold: %d bytes).",
+					diskFreeInBytes, this.thresholdBytes));
+			builder.down();
+		}
+	}
+
+	private static void verifyPathIsAccessible(File path) {
+		if (!path.exists()) {
+			throw new IllegalArgumentException(String.format("Path does not exist: %s", path));
+		}
+		if (!path.canRead()) {
+			throw new IllegalStateException(String.format("Path cannot be read: %s", path));
+		}
+	}
+}

spring-boot-actuator/src/test/java/org/springframework/boot/actuate/health/DiskSpaceHealthIndicatorTests.java

+/*
+ * Copyright 2014 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.io.File;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.runners.MockitoJUnitRunner;
+import org.springframework.test.util.ReflectionTestUtils;
+
+import static org.junit.Assert.assertEquals;
+import static org.mockito.Mockito.when;
+
+/**
+ * Tests for {@link DiskSpaceHealthIndicator}.
+ *
+ * @author Mattias Severson
+ */
+@RunWith(MockitoJUnitRunner.class)
+public class DiskSpaceHealthIndicatorTests {
+
+	static final long THRESHOLD_BYTES = 1024;
+
+	@Rule
+	public ExpectedException exception = ExpectedException.none();
+
+	@Mock
+	File fileMock;
+
+	HealthIndicator healthIndicator;
+
+	@Before
+	public void setUp() throws Exception {
+		this.healthIndicator =
+				new DiskSpaceHealthIndicator(DiskSpaceHealthIndicatorTests.class.getResource("").getPath(),
+				THRESHOLD_BYTES);
+		ReflectionTestUtils.setField(this.healthIndicator, "path", this.fileMock);
+	}
+
+	@Test
+	public void diskSpaceIsUp() throws Exception {
+		when(this.fileMock.getFreeSpace()).thenReturn(THRESHOLD_BYTES + 10);
+
+		Health health = this.healthIndicator.health();
+		assertEquals(Status.UP, health.getStatus());
+	}
+
+	@Test
+	public void diskSpaceIsDown() throws Exception {
+		when(this.fileMock.getFreeSpace()).thenReturn(THRESHOLD_BYTES - 10);
+
+		Health health = this.healthIndicator.health();
+		assertEquals(Status.DOWN, health.getStatus());
+	}
+
+	@Test
+	public void throwsExceptionForUnknownPath() {
+		exception.expect(IllegalArgumentException.class);
+		exception.expectMessage("Path does not exist: an_path_that_does_not_exist");
+
+		new DiskSpaceHealthIndicator("an_path_that_does_not_exist", THRESHOLD_BYTES);
+	}
+
+	@Test
+	public void throwsExceptionForNegativeThreshold() {
+		exception.expect(IllegalArgumentException.class);
+		exception.expectMessage("thresholdBytes must be greater than 0");
+
+		new DiskSpaceHealthIndicator(DiskSpaceHealthIndicatorTests.class.getResource("").getPath(), -1);
+	}
+}
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