Remove requirement for the disk space health indicator's path to exist when the app starts

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/system/DiskSpaceHealthIndicatorProperties.java

@@ -48,8 +48,6 @@ public File getPath() {
 	}
 
 	public void setPath(File path) {
-		Assert.isTrue(path.exists(), () -> "Path '" + path + "' does not exist");
-		Assert.isTrue(path.canRead(), () -> "Path '" + path + "' cannot be read");
 		this.path = path;
 	}
 

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/system/DiskSpaceHealthContributorAutoConfigurationTests.java

@@ -16,6 +16,8 @@
 
 package org.springframework.boot.actuate.autoconfigure.system;
 
+import java.util.UUID;
+
 import org.junit.jupiter.api.Test;
 
 import org.springframework.boot.actuate.autoconfigure.health.HealthContributorAutoConfiguration;
@@ -58,6 +60,13 @@ void thresholdCanBeCustomized() {
 		});
 	}
 
+	@Test
+	void pathIsNotRequiredToExist() {
+		String randomPath = "IDoNOTeXiST" + UUID.randomUUID().toString();
+		this.contextRunner.withPropertyValues("management.health.diskspace.path=" + randomPath)
+				.run((context) -> assertThat(context).hasSingleBean(DiskSpaceHealthIndicator.class));
+	}
+
 	@Test
 	void runWhenDisabledShouldNotCreateIndicator() {
 		this.contextRunner.withPropertyValues("management.health.diskspace.enabled:false")

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

@@ -59,7 +59,9 @@ public DiskSpaceHealthIndicator(File path, DataSize threshold) {
 	@Override
 	protected void doHealthCheck(Health.Builder builder) throws Exception {
 		long diskFreeInBytes = this.path.getUsableSpace();
-		if (diskFreeInBytes >= this.threshold.toBytes()) {
+		// return value of 0L means "the abstract pathname does not name a
+		// partition" which for our purposes means it's not usable i.e DOWN
+		if (diskFreeInBytes >= this.threshold.toBytes() && diskFreeInBytes != 0L) {
 			builder.up();
 		}
 		else {
@@ -68,7 +70,9 @@ protected void doHealthCheck(Health.Builder builder) throws Exception {
 			builder.down();
 		}
 		builder.withDetail("total", this.path.getTotalSpace()).withDetail("free", diskFreeInBytes)
-				.withDetail("threshold", this.threshold.toBytes());
+				.withDetail("threshold", this.threshold.toBytes()).withDetail("exists", this.path.exists())
+				.withDetail("canRead", this.path.canRead()).withDetail("canWrite", this.path.canWrite())
+				.withDetail("canExecute", this.path.canExecute());
 	}
 
 }

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/system/DiskSpaceHealthIndicatorPathTests.java

@@ -0,0 +1,106 @@
+/*
+ * Copyright 2012-2019 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
+ *
+ *      https://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.system;
+
+import java.io.File;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+import org.springframework.boot.actuate.health.Health;
+import org.springframework.boot.actuate.health.HealthIndicator;
+import org.springframework.boot.actuate.health.Status;
+import org.springframework.util.unit.DataSize;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.BDDMockito.given;
+
+/**
+ * Tests for the {@link DiskSpaceHealthIndicator} {@code path} parameter.
+ *
+ * @author Andreas Born
+ */
+class DiskSpaceHealthIndicatorPathTests {
+
+	private static final DataSize THRESHOLD = DataSize.ofKilobytes(1);
+
+	private static final DataSize ZERO_THRESHOLD = DataSize.ofBytes(0);
+
+	private static final DataSize TOTAL_SPACE = DataSize.ofKilobytes(10);
+
+	@Mock
+	private File fileMock;
+
+	private HealthIndicator healthIndicator;
+
+	@BeforeEach
+	void setUp() {
+		MockitoAnnotations.initMocks(this);
+		given(this.fileMock.exists()).willReturn(false);
+		given(this.fileMock.canRead()).willReturn(false);
+		given(this.fileMock.canWrite()).willReturn(false);
+		given(this.fileMock.canExecute()).willReturn(false);
+		this.healthIndicator = new DiskSpaceHealthIndicator(this.fileMock, THRESHOLD);
+	}
+
+	@Test
+	void diskSpaceIsDown() {
+		Health health = this.healthIndicator.health();
+		assertThat(health.getStatus()).isEqualTo(Status.DOWN);
+		assertThat(health.getDetails().get("threshold")).isEqualTo(THRESHOLD.toBytes());
+		assertThat(health.getDetails().get("free")).isEqualTo(0L);
+		assertThat(health.getDetails().get("total")).isEqualTo(0L);
+		assertThat(health.getDetails().get("exists")).isEqualTo(false);
+		assertThat(health.getDetails().get("canRead")).isEqualTo(false);
+		assertThat(health.getDetails().get("canWrite")).isEqualTo(false);
+		assertThat(health.getDetails().get("canExecute")).isEqualTo(false);
+	}
+
+	@Test
+	void diskSpaceIsDownWhenThresholdIsZero() {
+		this.healthIndicator = new DiskSpaceHealthIndicator(this.fileMock, ZERO_THRESHOLD);
+		Health health = this.healthIndicator.health();
+		assertThat(health.getStatus()).isEqualTo(Status.DOWN);
+		assertThat(health.getDetails().get("threshold")).isEqualTo(ZERO_THRESHOLD.toBytes());
+		assertThat(health.getDetails().get("free")).isEqualTo(0L);
+		assertThat(health.getDetails().get("total")).isEqualTo(0L);
+		assertThat(health.getDetails().get("exists")).isEqualTo(false);
+		assertThat(health.getDetails().get("canRead")).isEqualTo(false);
+		assertThat(health.getDetails().get("canWrite")).isEqualTo(false);
+		assertThat(health.getDetails().get("canExecute")).isEqualTo(false);
+	}
+
+	@Test
+	void diskSpaceIsUpWhenPathOnlyExists() {
+		long freeSpace = THRESHOLD.toBytes() + 10;
+		given(this.fileMock.getUsableSpace()).willReturn(freeSpace);
+		given(this.fileMock.getTotalSpace()).willReturn(TOTAL_SPACE.toBytes());
+		given(this.fileMock.exists()).willReturn(true);
+		Health health = this.healthIndicator.health();
+		assertThat(health.getStatus()).isEqualTo(Status.UP);
+		assertThat(health.getDetails().get("threshold")).isEqualTo(THRESHOLD.toBytes());
+		assertThat(health.getDetails().get("free")).isEqualTo(freeSpace);
+		assertThat(health.getDetails().get("total")).isEqualTo(TOTAL_SPACE.toBytes());
+		assertThat(health.getDetails().get("exists")).isEqualTo(true);
+		assertThat(health.getDetails().get("canRead")).isEqualTo(false);
+		assertThat(health.getDetails().get("canWrite")).isEqualTo(false);
+		assertThat(health.getDetails().get("canExecute")).isEqualTo(false);
+	}
+
+}

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

@@ -53,6 +53,8 @@ void setUp() {
 		MockitoAnnotations.initMocks(this);
 		given(this.fileMock.exists()).willReturn(true);
 		given(this.fileMock.canRead()).willReturn(true);
+		given(this.fileMock.canWrite()).willReturn(true);
+		given(this.fileMock.canExecute()).willReturn(true);
 		this.healthIndicator = new DiskSpaceHealthIndicator(this.fileMock, THRESHOLD);
 	}
 
@@ -66,6 +68,10 @@ void diskSpaceIsUp() {
 		assertThat(health.getDetails().get("threshold")).isEqualTo(THRESHOLD.toBytes());
 		assertThat(health.getDetails().get("free")).isEqualTo(freeSpace);
 		assertThat(health.getDetails().get("total")).isEqualTo(TOTAL_SPACE.toBytes());
+		assertThat(health.getDetails().get("exists")).isEqualTo(true);
+		assertThat(health.getDetails().get("canRead")).isEqualTo(true);
+		assertThat(health.getDetails().get("canWrite")).isEqualTo(true);
+		assertThat(health.getDetails().get("canExecute")).isEqualTo(true);
 	}
 
 	@Test
@@ -78,6 +84,10 @@ void diskSpaceIsDown() {
 		assertThat(health.getDetails().get("threshold")).isEqualTo(THRESHOLD.toBytes());
 		assertThat(health.getDetails().get("free")).isEqualTo(freeSpace);
 		assertThat(health.getDetails().get("total")).isEqualTo(TOTAL_SPACE.toBytes());
+		assertThat(health.getDetails().get("exists")).isEqualTo(true);
+		assertThat(health.getDetails().get("canRead")).isEqualTo(true);
+		assertThat(health.getDetails().get("canWrite")).isEqualTo(true);
+		assertThat(health.getDetails().get("canExecute")).isEqualTo(true);
 	}
 
 }