DM 1876 opentelemetry custom exporter for platform used in eg ms

hello-world-microservice/pom.xml

@@ -30,6 +30,11 @@
                 <type>pom</type>
                 <scope>import</scope>
             </dependency>
+            <dependency>
+                <groupId>c8y.agents.lpwan.backend</groupId>
+                <artifactId>lpwan-backend</artifactId>
+                <version>${c8y.version}</version>
+            </dependency>
         </dependencies>
     </dependencyManagement>
 
@@ -39,11 +44,27 @@
             <artifactId>microservice-autoconfigure</artifactId>
         </dependency>
 
+        <dependency>
+            <groupId>com.nsn.cumulocity.clients-java</groupId>
+            <artifactId>java-client-model</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+        </dependency>
+
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-test</artifactId>
             <scope>test</scope>
         </dependency>
+
+        <dependency>
+            <groupId>c8y.opentelemetry.exporters</groupId>
+            <artifactId>opentelemetry-metrics-exporters</artifactId>
+            <version>${c8y.version}</version>
+        </dependency>
     </dependencies>
 
     <build>

hello-world-microservice/src/main/configuration/cumulocity.json

@@ -9,6 +9,28 @@
   ],
   "roles":[
   ],
+  "resources": {
+    "cpu": "1000m",
+    "memory": "1Gi"
+  },
+  "billing" : {
+    "metrics" : [
+      {
+        "name": "hwGaugeMetricStSt",
+        "type": "NUMBER",
+        "aggregation": {
+          "function": "LATEST"
+        }
+      },
+      {
+        "name": "hwSumMetricStSt",
+        "type": "NUMBER",
+        "aggregation": {
+          "function": "SUM"
+        }
+      }
+    ]
+  },
   "livenessProbe":{
     "httpGet":{
       "path": "/health",

hello-world-microservice/src/main/java/c8y/example/helloworld/GaugeStorage.java

@@ -0,0 +1,22 @@
+package c8y.example.helloworld;
+
+import io.opentelemetry.api.metrics.ObservableDoubleGauge;
+import lombok.Getter;
+import lombok.Setter;
+import org.springframework.stereotype.Component;
+
+import java.util.ArrayList;
+import java.util.List;
+
+@Component
+public class GaugeStorage {
+    private List<ObservableDoubleGauge> observableDoubleGaugeList = new ArrayList<>();
+
+    public List<ObservableDoubleGauge> getObservableDoubleGaugeList() {
+        return observableDoubleGaugeList;
+    }
+
+    public void addObservableGauge(ObservableDoubleGauge doubleGauge) {
+        observableDoubleGaugeList.add(doubleGauge);
+    }
+}

hello-world-microservice/src/main/java/c8y/example/helloworld/HelloWorldMain.java

@@ -2,12 +2,18 @@
 
 import com.cumulocity.microservice.autoconfigure.MicroserviceApplication;
 import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.context.annotation.ComponentScan;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
 
 @MicroserviceApplication
-@RestController
+@ComponentScan(basePackages = {
+        "c8y.example.helloworld",
+        "com.cumulocity.exporters.platform",
+        "com.cumulocity.exporters.common"
+})
 public class HelloWorldMain {
 
     public static void main(String[] args) {

hello-world-microservice/src/main/java/c8y/example/helloworld/InventoryController.java

@@ -0,0 +1,86 @@
+package c8y.example.helloworld;
+
+import com.cumulocity.exporters.common.OpenTelemetryExporterStrategy;
+import com.cumulocity.exporters.common.OpenTelemetryExporterStrategyEnum;
+import com.cumulocity.exporters.common.OpenTelemetryExporterStrategyFactory;
+import com.cumulocity.exporters.platform.ExportCompletedEvent;
+import io.opentelemetry.api.OpenTelemetry;
+import io.opentelemetry.api.common.AttributeKey;
+import io.opentelemetry.api.common.Attributes;
+import io.opentelemetry.api.metrics.LongCounter;
+import io.opentelemetry.api.metrics.Meter;
+import io.opentelemetry.api.metrics.ObservableDoubleGauge;
+import io.opentelemetry.api.metrics.ObservableDoubleMeasurement;
+import lombok.extern.slf4j.Slf4j;
+import org.joda.time.DateTime;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.ApplicationListener;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.time.LocalDateTime;
+import java.util.List;
+import java.util.Random;
+import java.util.function.Consumer;
+
+@RestController
+@Slf4j
+public class InventoryController implements ApplicationListener<ExportCompletedEvent> {
+    private static String INSTRUMENTATION_SCOPE_NAME = HelloWorldMain.class.getName();
+
+    @Autowired
+    private OpenTelemetryExporterStrategyFactory exporterStrategyFactory;
+
+//    @Autowired
+//    private OpenTelemetry openTelemetry;
+
+    @Autowired
+    private GaugeStorage gaugeStorage;
+
+    private Meter meter;
+
+    @GetMapping("/gaugeMetric")
+    public String gaugeMetric() {
+        OpenTelemetryExporterStrategy openTelemetryExporterStrategy = exporterStrategyFactory.findStrategy(OpenTelemetryExporterStrategyEnum.PLATFORM);
+        OpenTelemetry openTelemetry = openTelemetryExporterStrategy.getOpenTelemetry();
+        meter = openTelemetry.getMeter(INSTRUMENTATION_SCOPE_NAME);
+        Random random = new Random();
+        int value = random.nextInt(20);
+        DateTime recordedTime = DateTime.now();
+        log.info("Sending gaugeMetric with value {}", value);
+        ObservableDoubleGauge gauge = meter
+                .gaugeBuilder("hwGaugeMetricStSt")
+                .buildWithCallback(
+                        getObservableDoubleMeasurementConsumer(value, recordedTime));
+        gaugeStorage.addObservableGauge(gauge);
+        return "test";
+    }
+
+    private Consumer<ObservableDoubleMeasurement> getObservableDoubleMeasurementConsumer(int value, DateTime recordedTime) {
+        return result -> result.record(value, Attributes.of(AttributeKey.stringKey(recordedTime.toString()), recordedTime.toString()));
+    }
+
+    @GetMapping("/sumMetric")
+    public String sumMetric() {
+        OpenTelemetryExporterStrategy openTelemetryExporterStrategy = exporterStrategyFactory.findStrategy(OpenTelemetryExporterStrategyEnum.PLATFORM);
+        OpenTelemetry openTelemetry = openTelemetryExporterStrategy.getOpenTelemetry();
+        meter = openTelemetry.getMeter(INSTRUMENTATION_SCOPE_NAME);
+        log.info("Sending sumMetric at {}", LocalDateTime.now());
+        Random random = new Random();
+        LongCounter sumCounter = meter.counterBuilder("hwSumMetricStSt")
+                .setUnit("units")
+                .build();
+        sumCounter.add(10);
+        return "test";
+    }
+
+    @Override
+    public void onApplicationEvent(ExportCompletedEvent event) {
+        int metricCollectionSize = event.getMetricCollectionSize();
+        List<ObservableDoubleGauge> gaugeList = gaugeStorage.getObservableDoubleGaugeList();
+        for(int metricIndex = 0; metricIndex < metricCollectionSize; metricIndex++) {
+            gaugeList.get(metricIndex).close();
+        }
+        gaugeList.subList(0, metricCollectionSize).clear();
+    }
+}

hello-world-microservice/src/main/resources/application.properties

@@ -1,6 +1,7 @@
 application.name=hello-world
-server.port=80
+server.port=12320
 
 # This parameter is provided by platform for microservice deployed in cumulocity.
 # You can set it up to your dedicated cumulocity address. You can get one by trying free trial on www.cumulocity.com
-C8Y.baseURL=
+C8Y.baseURL=http://localhost:30080
+spring.main.allow-bean-definition-overriding=true