add micrometer to collect metrics for prometheus

pom.xml

@@ -163,6 +163,21 @@
 			<artifactId>spring-boot-starter-actuator</artifactId>
 		</dependency>
 
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-aop</artifactId>
+		</dependency>
+
+		<dependency>
+			<groupId>io.micrometer</groupId>
+			<artifactId>micrometer-core</artifactId>
+		</dependency>
+
+		<dependency>
+			<groupId>io.micrometer</groupId>
+			<artifactId>micrometer-registry-prometheus</artifactId>
+		</dependency>
+
 		<!-- Add dump schema dependency -->
 		<dependency>
 			<groupId>eu.dnetlib.dhp</groupId>

src/main/java/eu/openaire/api/OpenaireRestApiApplication.java

@@ -2,8 +2,10 @@ package eu.openaire.api;
 
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.EnableAspectJAutoProxy;
 
 @SpringBootApplication
+@EnableAspectJAutoProxy
 public class OpenaireRestApiApplication {
 
 	public static void main(String[] args) {

src/main/java/eu/openaire/api/config/metrics/MetricsAspect.java

@@ -0,0 +1,50 @@
+package eu.openaire.api.config.metrics;
+
+import io.micrometer.core.annotation.Timed;
+import io.micrometer.core.instrument.MeterRegistry;
+import io.micrometer.core.instrument.Timer;
+import org.aspectj.lang.ProceedingJoinPoint;
+import org.aspectj.lang.annotation.Around;
+import org.aspectj.lang.annotation.Aspect;
+import org.aspectj.lang.reflect.MethodSignature;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+import java.lang.reflect.Method;
+
+@Aspect
+@Component
+public class MetricsAspect {
+
+    private final MeterRegistry meterRegistry;
+
+    @Autowired
+    public MetricsAspect(MeterRegistry meterRegistry) {
+        this.meterRegistry = meterRegistry;
+    }
+
+    /***
+     * Advice for timing methods annotated with {@link Timed}.
+     */
+    @Around("@annotation(io.micrometer.core.annotation.Timed)")
+    public Object timeAnnotatedMethods(ProceedingJoinPoint joinPoint) throws Throwable {
+        Method method = ((MethodSignature) joinPoint.getSignature()).getMethod();
+
+        String className = joinPoint.getTarget().getClass().getSimpleName();
+        String methodName = method.getName();
+        String timerName = className + "." + methodName;
+
+        Timer.Sample sample = Timer.start(meterRegistry);
+
+        try {
+            return joinPoint.proceed();
+        } finally {
+            sample.stop(Timer.builder(timerName)
+                    .tags("application", "openaire-search-api")
+                    .tags("class", className)
+                    .tags("method", methodName)
+                    .publishPercentiles(0.5, 0.95)
+                    .register(meterRegistry));
+        }
+    }
+}

src/main/java/eu/openaire/api/services/DataSourceService.java

@@ -11,6 +11,7 @@ import eu.openaire.api.mappers.response.ResponseResultsMapper;
 import eu.openaire.api.mappers.response.entities.DatasourceMapper;
 import eu.openaire.api.repositories.SolrRepository;
 import eu.openaire.api.solr.SolrQueryParams;
+import io.micrometer.core.annotation.Timed;
 import lombok.RequiredArgsConstructor;
 import lombok.SneakyThrows;
 import org.apache.logging.log4j.LogManager;
@@ -37,6 +38,7 @@ public class DataSourceService {
 	private final Logger log = LogManager.getLogger(this.getClass());
 
 	@SneakyThrows
+	@Timed
 	public Datasource getById(String id) {
 
 		var doc = solrRepository.getById(id);
@@ -48,6 +50,7 @@ public class DataSourceService {
 	}
 
 	@SneakyThrows
+	@Timed
 	public SearchResponse<Datasource> search(DataSourceRequest request) {
 
 		SolrQueryParams solrQueryParams = dataSourceRequestMapper.toSolrQuery(request);

src/main/java/eu/openaire/api/services/OrganizationService.java

@@ -11,6 +11,7 @@ import eu.openaire.api.mappers.response.ResponseResultsMapper;
 import eu.openaire.api.mappers.response.entities.OrganizationMapper;
 import eu.openaire.api.repositories.SolrRepository;
 import eu.openaire.api.solr.SolrQueryParams;
+import io.micrometer.core.annotation.Timed;
 import lombok.RequiredArgsConstructor;
 import lombok.SneakyThrows;
 import org.apache.logging.log4j.LogManager;
@@ -37,6 +38,7 @@ public class OrganizationService {
 	private final Logger log = LogManager.getLogger(this.getClass());
 
 	@SneakyThrows
+	@Timed
 	public Organization getById(String id) {
 
 		var doc = solrRepository.getById(id);
@@ -48,6 +50,7 @@ public class OrganizationService {
 	}
 
 	@SneakyThrows
+	@Timed
 	public SearchResponse<Organization> search(OrganizationRequest request) {
 
 		SolrQueryParams solrQueryParams = organizationRequestMapper.toSolrQuery(request);

src/main/java/eu/openaire/api/services/ProjectService.java

@@ -11,6 +11,7 @@ import eu.openaire.api.mappers.response.ResponseResultsMapper;
 import eu.openaire.api.mappers.response.entities.ProjectMapper;
 import eu.openaire.api.repositories.SolrRepository;
 import eu.openaire.api.solr.SolrQueryParams;
+import io.micrometer.core.annotation.Timed;
 import lombok.RequiredArgsConstructor;
 import lombok.SneakyThrows;
 import org.apache.logging.log4j.LogManager;
@@ -37,6 +38,7 @@ public class ProjectService {
     private final Logger log = LogManager.getLogger(this.getClass());
 
     @SneakyThrows
+    @Timed
     public Project getById(String id) {
 
         var doc = solrRepository.getById(id);
@@ -48,6 +50,7 @@ public class ProjectService {
     }
 
     @SneakyThrows
+    @Timed
     public SearchResponse<Project> search(ProjectRequest request) {
 
         SolrQueryParams solrQueryParams = projectRequestMapper.toSolrQuery(request);

src/main/java/eu/openaire/api/services/ResearchProductService.java

@@ -11,6 +11,7 @@ import eu.openaire.api.mappers.response.ResponseResultsMapper;
 import eu.openaire.api.mappers.response.entities.ResearchProductMapper;
 import eu.openaire.api.repositories.SolrRepository;
 import eu.openaire.api.solr.SolrQueryParams;
+import io.micrometer.core.annotation.Timed;
 import lombok.RequiredArgsConstructor;
 import lombok.SneakyThrows;
 import org.apache.logging.log4j.LogManager;
@@ -37,6 +38,7 @@ public class ResearchProductService {
 	private final Logger log = LogManager.getLogger(this.getClass());
 
 	@SneakyThrows
+	@Timed
 	public GraphResult getById(String id) {
 
 		var doc = solrRepository.getById(id);
@@ -49,6 +51,7 @@ public class ResearchProductService {
 	}
 
 	@SneakyThrows
+	@Timed
 	public SearchResponse<GraphResult> search(ResearchProductsRequest request) {
 
 		SolrQueryParams solrQueryParams = researchProductsRequestMapper.toSolrQuery(request);

src/main/resources/application.properties

@@ -15,8 +15,10 @@ 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
+# Expose health, info and metrics endpoint
+management.endpoints.web.exposure.include=health,info,prometheus
+management.endpoint.prometheus.enabled=true
+management.metrics.export.prometheus.enabled=true
 
 # Customize health endpoint settings
 management.endpoint.health.show-details=always