feat: add health check route (#87)

* feat: add health check route

* fix: remove unnecessary code

skill-tree/pom.xml

@@ -85,6 +85,16 @@
             <artifactId>junit-jupiter</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-actuator</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-junit-jupiter</artifactId>
+            <version>5.3.1</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
     <dependencyManagement>
         <dependencies>

skill-tree/src/main/java/com/RDS/skilltree/Health/HealthCheckController.java

@@ -0,0 +1,29 @@
+package com.RDS.skilltree.Health;
+
+import com.RDS.skilltree.metrics.MetricService;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.Map;
+
+@RestController
+@RequestMapping("/v1/health")
+@Slf4j
+public class HealthCheckController {
+
+    private final MetricService metricService;
+
+    @Autowired
+    public HealthCheckController(MetricService metricService) {
+        this.metricService = metricService;
+    }
+
+    @GetMapping("")
+    public Map<String, Object> checkHealth() {
+        double uptime = metricService.getUptime();
+        return Map.of("uptimeInSeconds", uptime);
+    }
+}

skill-tree/src/main/java/com/RDS/skilltree/metrics/MetricService.java

@@ -0,0 +1,24 @@
+package com.RDS.skilltree.metrics;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.actuate.metrics.MetricsEndpoint;
+import org.springframework.stereotype.Service;
+
+@Service
+public class MetricService {
+
+    private final MetricsEndpoint metricsEndpoint;
+
+    @Autowired
+    public MetricService(MetricsEndpoint metricsEndpoint) {
+        this.metricsEndpoint = metricsEndpoint;
+    }
+
+    public double getUptime() {
+        return metricsEndpoint.metric("process.uptime", null).getMeasurements()
+                .stream()
+                .findFirst()
+                .map(MetricsEndpoint.Sample::getValue)
+                .orElse(0.0);
+    }
+}

skill-tree/src/main/resources/application.properties

@@ -7,3 +7,5 @@ spring.jpa.hibernate.ddl-auto=${DB_DDL_POLICY}
 jwt.rds.public.key=${RDS_PUBLIC_KEY}
 API_V1_PREFIX=/api/v1
 spring.datasource.version=8.1.0
+management.endpoints.web.exposure.include=health,info,metrics
+

skill-tree/src/test/java/com/RDS/skilltree/unit/HealthCheckTest.java

@@ -0,0 +1,39 @@
+package com.RDS.skilltree.unit;
+
+import com.RDS.skilltree.Health.HealthCheckController;
+import com.RDS.skilltree.metrics.MetricService;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+import static org.mockito.Mockito.*;
+import static org.junit.jupiter.api.Assertions.*;
+
+class HealthCheckTest {
+
+    @Mock
+    private MetricService metricService;
+
+    private HealthCheckController healthCheckController;
+
+    @BeforeEach
+    void setUp() {
+        MockitoAnnotations.openMocks(this);
+        healthCheckController = new HealthCheckController(metricService);
+    }
+
+    @Test
+    void checkHealth() {
+        // Setup
+        when(metricService.getUptime()).thenReturn(123.0);
+
+        // Execute
+        var result = healthCheckController.checkHealth();
+
+        // Assert
+        assertNotNull(result);
+        assertTrue(result.containsKey("uptimeInSeconds"));
+        assertEquals(123.0, result.get("uptimeInSeconds"));
+    }
+}