Add OTLP exporter and static metric

openbas-api/pom.xml

@@ -225,6 +225,10 @@
             <groupId>io.opentelemetry</groupId>
             <artifactId>opentelemetry-exporter-logging</artifactId>
         </dependency>
+        <dependency>
+            <groupId>io.opentelemetry</groupId>
+            <artifactId>opentelemetry-exporter-otlp</artifactId>
+        </dependency>
         <dependency>
             <groupId>io.opentelemetry.semconv</groupId>
             <artifactId>opentelemetry-semconv</artifactId>

openbas-api/src/main/java/io/openbas/telemetry/InitTelemetryCommandLineRunner.java

@@ -0,0 +1,19 @@
+package io.openbas.telemetry;
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.boot.CommandLineRunner;
+import org.springframework.core.annotation.Order;
+import org.springframework.stereotype.Component;
+
+@Component
+@RequiredArgsConstructor
+@Order(2)
+public class InitTelemetryCommandLineRunner implements CommandLineRunner {
+
+  private final OpenTelemetryService openTelemetryService;
+
+  @Override
+  public void run(String... args) {
+    this.openTelemetryService.registerVersionMetric();
+  }
+}

openbas-api/src/main/java/io/openbas/telemetry/OpenTelemetryConfig.java

@@ -7,8 +7,10 @@
 import io.opentelemetry.context.propagation.ContextPropagators;
 import io.opentelemetry.context.propagation.TextMapPropagator;
 import io.opentelemetry.exporter.logging.LoggingMetricExporter;
+import io.opentelemetry.exporter.otlp.http.metrics.OtlpHttpMetricExporter;
 import io.opentelemetry.sdk.OpenTelemetrySdk;
 import io.opentelemetry.sdk.metrics.SdkMeterProvider;
+import io.opentelemetry.sdk.metrics.SdkMeterProviderBuilder;
 import io.opentelemetry.sdk.metrics.export.PeriodicMetricReader;
 import io.opentelemetry.sdk.resources.Resource;
 import io.opentelemetry.semconv.ResourceAttributes;
@@ -19,6 +21,7 @@
 import org.springframework.stereotype.Service;
 
 import static java.util.Objects.requireNonNull;
+import static org.springframework.util.StringUtils.hasText;
 
 @Service
 @RequiredArgsConstructor
@@ -34,13 +37,22 @@ public OpenTelemetry openTelemetry() {
         .put(ResourceAttributes.SERVICE_VERSION, requireNonNull(this.env.getProperty("info.app.version")))
         .build();
 
-    SdkMeterProvider sdkMeterProvider = SdkMeterProvider.builder()
-        .registerMetricReader(PeriodicMetricReader.builder(LoggingMetricExporter.create()).build())
+    // Log exporter
+    SdkMeterProviderBuilder sdkMeterProviderBuilder = SdkMeterProvider.builder()
+        .registerMetricReader(PeriodicMetricReader.builder(LoggingMetricExporter.create()).build());
+
+    // OTLP exporter
+    String exporterOtlpEndpoint = this.env.getProperty("telemetry.exporter.otlp.endpoint");
+    if (hasText(exporterOtlpEndpoint)) {
+      sdkMeterProviderBuilder.registerMetricReader(PeriodicMetricReader.builder(
+          OtlpHttpMetricExporter.builder().setEndpoint(exporterOtlpEndpoint).build()
+      ).build());
+    }
+
+    SdkMeterProvider sdkMeterProvider = sdkMeterProviderBuilder
         .setResource(resource)
         .build();
 
-    // TODO: Add file exporter
-
     return OpenTelemetrySdk.builder()
         .setMeterProvider(sdkMeterProvider)
         .setPropagators(ContextPropagators.create(

openbas-api/src/main/java/io/openbas/telemetry/OpenTelemetryService.java

@@ -4,16 +4,22 @@
 import io.opentelemetry.api.common.Attributes;
 import io.opentelemetry.api.metrics.LongCounter;
 import io.opentelemetry.api.metrics.Meter;
+import io.opentelemetry.api.metrics.ObservableDoubleMeasurement;
 import jakarta.annotation.PostConstruct;
 import jakarta.validation.constraints.NotBlank;
 import lombok.RequiredArgsConstructor;
+import org.springframework.core.env.Environment;
 import org.springframework.stereotype.Service;
 
+import java.util.Objects;
+
 @Service
 @RequiredArgsConstructor
 public class OpenTelemetryService {
 
-  private static final String PREFIX_PRODUCT;
+  private static final String PREFIX_PRODUCT = "openbas";
+
+  private final Environment env;
 
   private final Meter meter;
 
@@ -36,4 +42,17 @@ public void login(@NotBlank final String email) {
     this.longCounter.add(1); // Global login count
   }
 
+  // -- STATIC --
+
+  // Not sure if it's the good way
+  public void registerVersionMetric() {
+    ObservableDoubleMeasurement longGauge = this.meter
+        .gaugeBuilder(PREFIX_PRODUCT + "app.version")
+        .setDescription("Software version")
+        .setUnit("version")
+        .buildObserver();
+    String appVersion = Objects.requireNonNull(this.env.getProperty("info.app.version"));
+    longGauge.record(1, Attributes.of(AttributeKey.stringKey("app.version"), appVersion));
+  }
+
 }