Add health check with actuator

pom.xml

@@ -164,6 +164,12 @@
 			<version>2.0.1.Final</version>
 		</dependency>
 
+		<!-- Add actuator dependency -->
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-actuator</artifactId>
+		</dependency>
+
 		<!-- Add dump schema dependency -->
 		<dependency>
 			<groupId>eu.dnetlib.dhp</groupId>

src/main/java/eu/openaire/api/config/health/HealthCheck.java

@@ -0,0 +1,45 @@
+package eu.openaire.api.config;
+
+import eu.openaire.api.repositories.SolrRepository;
+import org.apache.solr.client.solrj.SolrServerException;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.actuate.health.Health;
+import org.springframework.boot.actuate.health.HealthIndicator;
+import org.springframework.stereotype.Component;
+
+import java.io.IOException;
+
+@Component
+public class HealthCheck implements HealthIndicator {
+
+	@Autowired
+	private SolrRepository solrRepository;
+
+	@Override
+	public Health health() {
+
+		System.out.println("HEALTH CHECK");
+
+		// Custom health check logic
+		boolean isHealthy = checkHealth();
+		if (isHealthy) {
+			return Health.up().withDetail("message", "Successfully pinged Solr instances").build();
+		} else {
+			return Health.down().withDetail("message", "Could not ping Solr instances; please check the logs for details").build();
+		}
+	}
+
+	private boolean checkHealth() {
+
+		// Ping Solr cluster to check health
+		try {
+			if (solrRepository.ping().getStatus() != 0) {
+				return false;
+			}
+		} catch (SolrServerException | IOException e) {
+			return false;
+		}
+
+		return true;
+	}
+}

src/main/java/eu/openaire/api/config/health/SolrStartupHealthCheck.java

@@ -0,0 +1,2 @@
+package eu.openaire.api.config.health;public class SolrStartupHealthCheck {
+}

src/main/java/eu/openaire/api/repositories/SolrRepository.java

@@ -10,6 +10,7 @@ import org.apache.solr.client.solrj.SolrQuery;
 import org.apache.solr.client.solrj.SolrServerException;
 import org.apache.solr.client.solrj.response.QueryResponse;
 import org.apache.solr.common.SolrDocument;
+import org.apache.solr.common.SolrException;
 import org.springframework.stereotype.Repository;
 
 import java.io.IOException;
@@ -62,4 +63,8 @@ public class SolrRepository {
         return solrConnectionManager.getSolrClient().query(query);
 
     }
+
+    public void ping() throws SolrServerException, SolrException, IOException {
+        solrConnectionManager.ping();
+    }
 }

src/main/java/eu/openaire/api/solr/SolrConnectionManager.java

@@ -8,6 +8,7 @@ import org.apache.logging.log4j.Logger;
 import org.apache.solr.client.solrj.SolrClient;
 import org.apache.solr.client.solrj.SolrServerException;
 import org.apache.solr.client.solrj.impl.CloudSolrClient;
+import org.apache.solr.common.SolrException;
 import org.springframework.context.annotation.Scope;
 import org.springframework.stereotype.Component;
 
@@ -46,10 +47,15 @@ public class SolrConnectionManager {
         // set the appropriate Solr collection
         ((CloudSolrClient) solrClient).setDefaultCollection(solrProperties.getCollection());
 
-        log.info("Creating Solr client - Ping response: " + solrClient.ping().toString());
+        // uncomment ping below, to crash app on startup if Solr is not available
+//        this.ping();
 
     }
 
+    public void ping() throws IOException, SolrException, SolrServerException {
+        log.info("Solr ping response: " + solrClient.ping().toString());
+    }
+
     @PreDestroy
     private void closeClient() throws IOException {
 
@@ -58,6 +64,5 @@ public class SolrConnectionManager {
         if (solrClient != null) {
             solrClient.close();
         }
-
     }
 }

src/main/resources/application.properties

@@ -12,3 +12,13 @@ logging.level.org.springframework.web=DEBUG
 #removes 'trace' field from error responses; alternatively remove 'spring-boot-devtools' dependency
 server.error.include-stacktrace=never 
 
+# Enable the health endpoint
+management.endpoint.health.enabled=true
+
+# Expose the health endpoint
+management.endpoints.web.exposure.include=health,info
+
+# Customize health endpoint settings
+management.endpoint.health.show-details=always
+management.endpoint.health.show-components=always
+