Add health indicator for Neo4j

See gh-9557

Author: Eric Spiegelberg

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

@@ -26,6 +26,7 @@
 import com.couchbase.client.java.Bucket;
 import com.datastax.driver.core.Cluster;
 import org.apache.solr.client.solrj.SolrClient;
+import org.neo4j.ogm.session.SessionFactory;
 
 import org.springframework.amqp.rabbit.core.RabbitTemplate;
 import org.springframework.beans.factory.InitializingBean;
@@ -42,6 +43,7 @@
 import org.springframework.boot.actuate.health.LdapHealthIndicator;
 import org.springframework.boot.actuate.health.MailHealthIndicator;
 import org.springframework.boot.actuate.health.MongoHealthIndicator;
+import org.springframework.boot.actuate.health.Neo4jHealthIndicator;
 import org.springframework.boot.actuate.health.OrderedHealthAggregator;
 import org.springframework.boot.actuate.health.RabbitHealthIndicator;
 import org.springframework.boot.actuate.health.RedisHealthIndicator;
@@ -59,6 +61,7 @@
 import org.springframework.boot.autoconfigure.data.elasticsearch.ElasticsearchAutoConfiguration;
 import org.springframework.boot.autoconfigure.data.ldap.LdapDataAutoConfiguration;
 import org.springframework.boot.autoconfigure.data.mongo.MongoDataAutoConfiguration;
+import org.springframework.boot.autoconfigure.data.neo4j.Neo4jDataAutoConfiguration;
 import org.springframework.boot.autoconfigure.data.redis.RedisAutoConfiguration;
 import org.springframework.boot.autoconfigure.elasticsearch.jest.JestAutoConfiguration;
 import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
@@ -91,6 +94,7 @@
  * @author Phillip Webb
  * @author Tommy Ludwig
  * @author Eddú Meléndez
+ * @author Eric Spiegelberg
  * @since 1.1.0
  */
 @Configuration
@@ -102,7 +106,7 @@
 		LdapDataAutoConfiguration.class, MailSenderAutoConfiguration.class,
 		MongoAutoConfiguration.class, MongoDataAutoConfiguration.class,
 		RabbitAutoConfiguration.class, RedisAutoConfiguration.class,
-		SolrAutoConfiguration.class })
+		SolrAutoConfiguration.class, Neo4jDataAutoConfiguration.class })
 @EnableConfigurationProperties({ HealthIndicatorProperties.class })
 @Import({
 		ElasticsearchHealthIndicatorConfiguration.ElasticsearchClientHealthIndicatorConfiguration.class,
@@ -257,6 +261,28 @@ public HealthIndicator ldapHealthIndicator() {
 
 	}
 
+	@Configuration
+	@ConditionalOnClass(SessionFactory.class)
+	@ConditionalOnBean(SessionFactory.class)
+	@ConditionalOnEnabledHealthIndicator("neo4j")
+	public static class Neo4jHealthIndicatorConfiguration extends
+			CompositeHealthIndicatorConfiguration<Neo4jHealthIndicator, SessionFactory> {
+
+		private final Map<String, SessionFactory> sessionFactories;
+
+		public Neo4jHealthIndicatorConfiguration(
+				Map<String, SessionFactory> sessionFactories) {
+			this.sessionFactories = sessionFactories;
+		}
+
+		@Bean
+		@ConditionalOnMissingBean(name = "neo4jHealthIndicator")
+		public HealthIndicator neo4jHealthIndicator() {
+			return createHealthIndicator(this.sessionFactories);
+		}
+
+	}
+
 	@Configuration
 	@ConditionalOnBean(MongoTemplate.class)
 	@ConditionalOnEnabledHealthIndicator("mongo")

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/health/Neo4jHealthIndicator.java

@@ -0,0 +1,64 @@
+/*
+ * 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.health;
+
+import java.util.Collections;
+import java.util.Map;
+
+import org.neo4j.ogm.model.Result;
+import org.neo4j.ogm.session.Session;
+import org.neo4j.ogm.session.SessionFactory;
+
+import org.springframework.boot.context.properties.ConfigurationProperties;
+
+/**
+ * {@link HealthIndicator} that tests the status of a Neo4j by executing a Cypher
+ * statement.
+ *
+ * @author Eric Spiegelberg
+ */
+@ConfigurationProperties(prefix = "management.health.neo4j", ignoreUnknownFields = false)
+public class Neo4jHealthIndicator extends AbstractHealthIndicator {
+
+	private final SessionFactory sessionFactory;
+
+	/**
+	 * The Cypher statement used to verify Neo4j is up.
+	 */
+	public static final String CYPHER = "match (n) return count(n) as nodes";
+
+	/**
+	 * Create a new {@link Neo4jHealthIndicator} using the specified
+	 * {@link SessionFactory}.
+	 * @param sessionFactory the SessionFactory
+	 */
+	public Neo4jHealthIndicator(SessionFactory sessionFactory) {
+		this.sessionFactory = sessionFactory;
+	}
+
+	@Override
+	protected void doHealthCheck(Health.Builder builder) throws Exception {
+		Session session = this.sessionFactory.openSession();
+
+		Result result = session.query(CYPHER, Collections.emptyMap());
+		Iterable<Map<String, Object>> results = result.queryResults();
+		int nodes = (int) results.iterator().next().get("nodes");
+
+		builder.up().withDetail("nodes", nodes);
+	}
+
+}

spring-boot-actuator/src/main/resources/META-INF/additional-spring-configuration-metadata.json

@@ -181,6 +181,12 @@
     "description": "Enable Mail health check.",
     "defaultValue": true
   },
+  {
+    "name": "management.health.neo4j.enabled",
+    "type": "java.lang.Boolean",
+    "description": "Enable Neo4j health check.",
+    "defaultValue": true
+  },
   {
     "name": "management.info.build.enabled",
     "type": "java.lang.Boolean",

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

@@ -23,6 +23,7 @@
 import io.searchbox.client.JestClient;
 import org.junit.After;
 import org.junit.Test;
+import org.neo4j.ogm.session.SessionFactory;
 
 import org.springframework.boot.actuate.health.ApplicationHealthIndicator;
 import org.springframework.boot.actuate.health.CassandraHealthIndicator;
@@ -38,6 +39,7 @@
 import org.springframework.boot.actuate.health.LdapHealthIndicator;
 import org.springframework.boot.actuate.health.MailHealthIndicator;
 import org.springframework.boot.actuate.health.MongoHealthIndicator;
+import org.springframework.boot.actuate.health.Neo4jHealthIndicator;
 import org.springframework.boot.actuate.health.RabbitHealthIndicator;
 import org.springframework.boot.actuate.health.RedisHealthIndicator;
 import org.springframework.boot.actuate.health.SolrHealthIndicator;
@@ -76,6 +78,7 @@
  * @author Stephane Nicoll
  * @author Andy Wilkinson
  * @author Eddú Meléndez
+ * @author Eric Spiegelberg
  */
 public class HealthIndicatorAutoConfigurationTests {
 
@@ -578,6 +581,34 @@ public void notLdapHealthIndicator() throws Exception {
 				.isEqualTo(ApplicationHealthIndicator.class);
 	}
 
+	@Test
+	public void neo4jHealthIndicator() throws Exception {
+		TestPropertyValues.of("management.health.diskspace.enabled:false")
+				.applyTo(this.context);
+		this.context.register(Neo4jConfiguration.class, ManagementServerProperties.class,
+				HealthIndicatorAutoConfiguration.class);
+		this.context.refresh();
+		Map<String, HealthIndicator> beans = this.context
+				.getBeansOfType(HealthIndicator.class);
+		assertThat(beans.size()).isEqualTo(1);
+		assertThat(beans.values().iterator().next().getClass())
+				.isEqualTo(Neo4jHealthIndicator.class);
+	}
+
+	@Test
+	public void notNeo4jHealthIndicator() throws Exception {
+		TestPropertyValues.of("management.health.diskspace.enabled:false",
+				"management.health.neo4j.enabled:false").applyTo(this.context);
+		this.context.register(Neo4jConfiguration.class, ManagementServerProperties.class,
+				HealthIndicatorAutoConfiguration.class);
+		this.context.refresh();
+		Map<String, HealthIndicator> beans = this.context
+				.getBeansOfType(HealthIndicator.class);
+		assertThat(beans.size()).isEqualTo(1);
+		assertThat(beans.values().iterator().next().getClass())
+				.isEqualTo(ApplicationHealthIndicator.class);
+	}
+
 	@Configuration
 	@EnableConfigurationProperties
 	protected static class DataSourceConfig {
@@ -659,4 +690,14 @@ public LdapOperations ldapOperations() {
 
 	}
 
+	@Configuration
+	protected static class Neo4jConfiguration {
+
+		@Bean
+		public SessionFactory sessionFactory() {
+			return mock(SessionFactory.class);
+		}
+
+	}
+
 }

spring-boot-actuator/src/test/java/org/springframework/boot/actuate/health/Neo4jHealthIndicatorTests.java

@@ -0,0 +1,100 @@
+/*
+ * 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.health;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+import org.neo4j.ogm.exception.CypherException;
+import org.neo4j.ogm.model.Result;
+import org.neo4j.ogm.session.Session;
+import org.neo4j.ogm.session.SessionFactory;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.BDDMockito.given;
+import static org.mockito.Mockito.mock;
+
+/**
+ * Tests for {@link Neo4jHealthIndicator}.
+ *
+ * @author Eric Spiegelberg
+ */
+public class Neo4jHealthIndicatorTests {
+
+	private Result result;
+	private Session session;
+	private SessionFactory sessionFactory;
+
+	private Neo4jHealthIndicator neo4jHealthIndicator;
+
+	private Map<String, Object> emptyParameters = new HashMap<>();
+
+	@Before
+	public void before() {
+		this.result = mock(Result.class);
+		this.session = mock(Session.class);
+		this.sessionFactory = mock(SessionFactory.class);
+
+		given(this.sessionFactory.openSession()).willReturn(this.session);
+
+		this.neo4jHealthIndicator = new Neo4jHealthIndicator(this.sessionFactory);
+	}
+
+	@Test
+	public void neo4jUp() {
+		given(this.session.query(Neo4jHealthIndicator.CYPHER, this.emptyParameters))
+				.willReturn(this.result);
+
+		int nodeCount = 500;
+		Map<String, Object> expectedCypherDetails = new HashMap<>();
+		expectedCypherDetails.put("nodes", nodeCount);
+
+		List<Map<String, Object>> queryResults = new ArrayList<>();
+		queryResults.add(expectedCypherDetails);
+
+		given(this.result.queryResults()).willReturn(queryResults);
+
+		Health health = this.neo4jHealthIndicator.health();
+		assertThat(health.getStatus()).isEqualTo(Status.UP);
+
+		Map<String, Object> details = health.getDetails();
+		int nodeCountFromDetails = (int) details.get("nodes");
+
+		Assert.assertEquals(nodeCount, nodeCountFromDetails);
+
+	}
+
+	@Test
+	public void neo4jDown() {
+
+		CypherException cypherException = new CypherException("Error executing Cypher",
+				"Neo.ClientError.Statement.SyntaxError",
+				"Unable to execute invalid Cypher");
+
+		given(this.session.query(Neo4jHealthIndicator.CYPHER, this.emptyParameters))
+				.willThrow(cypherException);
+
+		Health health = this.neo4jHealthIndicator.health();
+		assertThat(health.getStatus()).isEqualTo(Status.DOWN);
+	}
+
+}