WIP for #670

Author: oharsta

myconext-server/pom.xml

@@ -42,6 +42,11 @@
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-actuator</artifactId>
         </dependency>
+        <dependency>
+            <groupId>io.micrometer</groupId>
+            <artifactId>micrometer-registry-prometheus</artifactId>
+            <version>1.15.1</version>
+        </dependency>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-web</artifactId>

myconext-server/src/main/java/myconext/api/MetricsController.java

@@ -0,0 +1,19 @@
+package myconext.api;
+
+import io.swagger.v3.oas.annotations.Hidden;
+import myconext.repository.MetricsRepository;
+import myconext.repository.UserRepository;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+@Hidden
+public class MetricsController {
+
+    private final UserRepository userRepository;
+    private final MetricsRepository metricsRepository;
+
+    public MetricsController(UserRepository userRepository, MetricsRepository metricsRepository) {
+        this.userRepository = userRepository;
+        this.metricsRepository = metricsRepository;
+    }
+}

myconext-server/src/main/java/myconext/repository/MetricsRepository.java

@@ -0,0 +1,64 @@
+package myconext.repository;
+
+import com.mongodb.client.AggregateIterable;
+import myconext.model.User;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.data.mongodb.core.MongoTemplate;
+import org.springframework.data.mongodb.core.aggregation.*;
+import org.bson.Document;
+import org.springframework.stereotype.Repository;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+
+@Repository
+public class MetricsRepository {
+
+    private final MongoTemplate mongoTemplate;
+
+    public MetricsRepository(MongoTemplate mongoTemplate) {
+        this.mongoTemplate = mongoTemplate;
+    }
+
+    public Number getTotalLinkedAccountCount() {
+        UnwindOperation unwindLinkedAccounts = Aggregation.unwind("linkedAccounts");
+        CountOperation countTotal = Aggregation.count().as("totalLinkedAccounts");
+        TypedAggregation<User> aggregation = Aggregation.newAggregation(
+                User.class,
+                unwindLinkedAccounts,
+                countTotal
+        );
+        AggregationResults<Map> results = mongoTemplate.aggregate(
+                aggregation,
+                Map.class
+        );
+        return (Number) results.getUniqueMappedResult().get("totalLinkedAccounts");
+    }
+
+    // Alternative approach: Using MongoTemplate's native execute method
+    public Number countTotalLinkedAccountsNativeExecute() {
+        /*
+            users.aggregate([
+                  {
+                    "$unwind": "$linkedAccounts"
+                  },
+                  {
+                    "$count": "totalLinkedAccounts"
+                  }
+                ])
+
+         */
+        return mongoTemplate.execute("users", collection -> {
+            List<Document> pipeline = Arrays.asList(
+                    Document.parse("{ \"$unwind\": \"$linkedAccounts\" }"),
+                    Document.parse("{ \"$count\": \"totalLinkedAccounts\" }")
+            );
+
+            AggregateIterable<Document> result = collection.aggregate(pipeline);
+            Document doc = result.first();
+
+            return doc != null ? doc.getInteger("totalLinkedAccounts") : 0;
+        });
+    }
+}

myconext-server/src/main/resources/application.yml

@@ -267,18 +267,22 @@ management:
   endpoints:
     web:
       exposure:
-        include: "health,info"
+#        include: "health,info,prometheus"
+        include: "*"
       base-path: "/internal"
   endpoint:
     info:
       access: unrestricted
     health:
       access: unrestricted
-      show-details: never
+      show-details: when_authorized
+    prometheus:
+      access: unrestricted
+      show-details: always
     mappings:
       access: none
     metrics:
-      access: none
+      access: unrestricted
   info:
     git:
       mode: full

myconext-server/src/test/java/myconext/repository/MetricsRepositoryTest.java

@@ -0,0 +1,25 @@
+package myconext.repository;
+
+import myconext.AbstractIntegrationTest;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+
+import java.util.Map;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class MetricsRepositoryTest extends AbstractIntegrationTest {
+
+    @Autowired
+    private MetricsRepository metricsRepository;
+
+    @Test
+    void getTotalLinkedAccountCount() {
+        Number totalLinkedAccountCount = metricsRepository.getTotalLinkedAccountCount();
+        System.out.println(totalLinkedAccountCount);
+
+        Number l = metricsRepository.countTotalLinkedAccountsNativeExecute();
+        System.out.println(l);
+    }
+
+}