Log failing calls to health indicators

Closes gh-22632

Co-authored-by: Madhura Bhave <bhavem@vmware.com>

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

@@ -82,15 +82,23 @@ public abstract class AbstractHealthIndicator implements HealthIndicator {
 			doHealthCheck(builder);
 		}
 		catch (Exception ex) {
-			if (this.logger.isWarnEnabled()) {
-				String message = this.healthCheckFailedMessage.apply(ex);
-				this.logger.warn(StringUtils.hasText(message) ? message : DEFAULT_MESSAGE, ex);
-			}
 			builder.down(ex);
 		}
+		logExceptionIfPresent(builder);
 		return builder.build();
 	}
 
+	private void logExceptionIfPresent(Builder builder) {
+		Throwable ex = builder.getException();
+		if (ex != null && this.logger.isWarnEnabled()) {
+			String message = null;
+			if (ex instanceof Exception) {
+				message = this.healthCheckFailedMessage.apply((Exception) ex);
+			}
+			this.logger.warn(StringUtils.hasText(message) ? message : DEFAULT_MESSAGE, ex);
+		}
+	}
+
 	/**
 	 * Actual health check logic.
 	 * @param builder the {@link Builder} to report health status and details

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

@@ -193,6 +193,8 @@ public final class Health extends HealthComponent {
 
 		private Map<String, Object> details;
 
+		private Throwable exception;
+
 		/**
 		 * Create new Builder instance.
 		 */
@@ -231,6 +233,7 @@ public final class Health extends HealthComponent {
 		 */
 		public Builder withException(Throwable ex) {
 			Assert.notNull(ex, "Exception must not be null");
+			this.exception = ex;
 			return withDetail("error", ex.getClass().getName() + ": " + ex.getMessage());
 		}
 
@@ -320,6 +323,15 @@ public final class Health extends HealthComponent {
 			return this;
 		}
 
+		/**
+		 * Return the {@link Exception}.
+		 * @return the exception or {@code null} if the builder has no exception
+		 * @since 2.6.0
+		 */
+		public Throwable getException() {
+			return this.exception;
+		}
+
 		/**
 		 * Create a new {@link Health} instance with the previously specified code and
 		 * details.

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

@@ -0,0 +1,111 @@
+/*
+ * Copyright 2012-2020 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.health;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+
+import org.springframework.boot.actuate.health.Health.Builder;
+import org.springframework.boot.test.system.CapturedOutput;
+import org.springframework.boot.test.system.OutputCaptureExtension;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link AbstractHealthIndicator}.
+ *
+ * @author Stephane Nicoll
+ * @author Madhura Bhave
+ */
+@ExtendWith(OutputCaptureExtension.class)
+class AbstractHealthIndicatorTests {
+
+	@Test
+	void healthCheckWhenUpDoesNotLogHealthCheckFailedMessage(CapturedOutput output) {
+		Health heath = new AbstractHealthIndicator("Test message") {
+			@Override
+			protected void doHealthCheck(Builder builder) {
+				builder.up();
+			}
+		}.health();
+		assertThat(heath.getStatus()).isEqualTo(Status.UP);
+		assertThat(output).doesNotContain("Test message");
+	}
+
+	@Test
+	void healthCheckWhenDownWithExceptionThrownDoesNotLogHealthCheckFailedMessage(CapturedOutput output) {
+		Health heath = new AbstractHealthIndicator("Test message") {
+			@Override
+			protected void doHealthCheck(Builder builder) {
+				throw new IllegalStateException("Test exception");
+			}
+		}.health();
+		assertThat(heath.getStatus()).isEqualTo(Status.DOWN);
+		assertThat(output).contains("Test message").contains("Test exception");
+	}
+
+	@Test
+	void healthCheckWhenDownWithExceptionConfiguredDoesNotLogHealthCheckFailedMessage(CapturedOutput output) {
+		Health heath = new AbstractHealthIndicator("Test message") {
+			@Override
+			protected void doHealthCheck(Builder builder) {
+				builder.down().withException(new IllegalStateException("Test exception"));
+			}
+		}.health();
+		assertThat(heath.getStatus()).isEqualTo(Status.DOWN);
+		assertThat(output).contains("Test message").contains("Test exception");
+	}
+
+	@Test
+	void healthCheckWhenDownWithExceptionConfiguredDoesNotLogHealthCheckFailedMessageTwice(CapturedOutput output) {
+		Health heath = new AbstractHealthIndicator("Test message") {
+			@Override
+			protected void doHealthCheck(Builder builder) {
+				IllegalStateException ex = new IllegalStateException("Test exception");
+				builder.down().withException(ex);
+				throw ex;
+			}
+		}.health();
+		assertThat(heath.getStatus()).isEqualTo(Status.DOWN);
+		assertThat(output).contains("Test message").containsOnlyOnce("Test exception");
+	}
+
+	@Test
+	void healthCheckWhenDownWithExceptionAndNoFailureMessageLogsDefaultMessage(CapturedOutput output) {
+		Health heath = new AbstractHealthIndicator() {
+			@Override
+			protected void doHealthCheck(Builder builder) {
+				builder.down().withException(new IllegalStateException("Test exception"));
+			}
+		}.health();
+		assertThat(heath.getStatus()).isEqualTo(Status.DOWN);
+		assertThat(output).contains("Health check failed").contains("Test exception");
+	}
+
+	@Test
+	void healthCheckWhenDownWithErrorLogsDefaultMessage(CapturedOutput output) {
+		Health heath = new AbstractHealthIndicator("Test Message") {
+			@Override
+			protected void doHealthCheck(Builder builder) {
+				builder.down().withException(new Error("Test error"));
+			}
+		}.health();
+		assertThat(heath.getStatus()).isEqualTo(Status.DOWN);
+		assertThat(output).contains("Health check failed").contains("Test error");
+	}
+
+}