Calendar app: use instrumentation annotations (#127)

* Add a dependency on the `opentelemetry-instrumentation-annotations` library to use `@WithSpan` annotation. * Move `getDate` method to the `CalendarService` class. * Update OTel Java Agent to the latest `2.6.0` version * Fix helm instructions in the README
DataDog · Aug 14, 2024 · 22de51b · 22de51b
1 parent ec6280b
commit 22de51b
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diff --git a/apps/rest-services/java/calendar/README.md b/apps/rest-services/java/calendar/README.md
@@ -2,7 +2,7 @@
 
 ```
 GET /calendar
-Returns a random date in 2022.
+Returns a random date within the current year.
 ```
 
 ```
@@ -70,11 +70,11 @@ As of now, in order for trace/log correlation to work the `trace_id` key needs t
 Install calendar in K8s with OTel SDK
 
 ```
-helm install -n otel-ingest calendar-otel-java ./calendar/k8s/ --set image.repository=dineshgurumurthydd/calendar-java --set image.tag=otel-0.1,node_group=ng-1
+helm install -n otel-ingest calendar-otel-java ./deploys/calendar/ --set image.repository=dineshgurumurthydd/calendar-java --set image.tag=otel-0.1,node_group=ng-1
 ```
 
 Install calendar in K8s with DD SDK
 
 ```
-helm install -n otel-ingest calendar-dd-java ./calendar-dd/k8s/ --set image.repository=dineshgurumurthydd/calendar-java --set image.tag=otel-0.1,node_group=ng-1
+helm install -n otel-ingest calendar-dd-java ./deploys/calendar-dd/ --set image.repository=dineshgurumurthydd/calendar-java --set image.tag=otel-0.1,node_group=ng-1
 ```
diff --git a/apps/rest-services/java/calendar/build.gradle b/apps/rest-services/java/calendar/build.gradle
@@ -9,7 +9,6 @@ plugins {
     id 'application'
     id 'org.springframework.boot' version '3.0.2'
     id 'io.spring.dependency-management' version '1.1.0'
-
 }
 
 repositories {
@@ -28,8 +27,7 @@ dependencies {
     implementation 'org.slf4j:slf4j-api:2.0.6'
     runtimeOnly 'io.opentelemetry.instrumentation:opentelemetry-logback-appender-1.0:1.28.0-alpha'
     implementation 'io.opentelemetry:opentelemetry-api:1.28.0'
-
-
+    implementation 'io.opentelemetry.instrumentation:opentelemetry-instrumentation-annotations:2.6.0'
 }
 
 group = 'com.datadog.example'

diff --git a/apps/rest-services/java/calendar/deploys/Dockerfile.otel b/apps/rest-services/java/calendar/deploys/Dockerfile.otel
@@ -6,7 +6,7 @@ FROM openjdk:17-buster
 RUN apt-get update -y; apt-get install curl -y
 
 WORKDIR /home/otel
-RUN curl -Lo opentelemetry-javaagent.jar  https://github.com/open-telemetry/opentelemetry-java-instrumentation/releases/download/v2.4.0/opentelemetry-javaagent.jar
+RUN curl -Lo opentelemetry-javaagent.jar  https://github.com/open-telemetry/opentelemetry-java-instrumentation/releases/download/v2.6.0/opentelemetry-javaagent.jar
 COPY . calendar/
 
 WORKDIR /home/otel/calendar

diff --git a/apps/rest-services/java/calendar/src/main/java/com/otel/controller/CalendarController.java b/apps/rest-services/java/calendar/src/main/java/com/otel/controller/CalendarController.java
@@ -1,24 +1,15 @@
 /*
 Unless explicitly stated otherwise all files in this repository are licensed
 under the Apache 2.0 License.
+
+This product includes software developed at Datadog (https://www.datadoghq.com/)
+Copyright 2024 Datadog, Inc.
 */
 package com.otel.controller;
 
-import io.opentelemetry.api.OpenTelemetry;
-import io.opentelemetry.api.metrics.DoubleHistogram;
-import io.opentelemetry.api.metrics.LongCounter;
-import io.opentelemetry.api.metrics.Meter;
-import io.opentelemetry.api.metrics.ObservableDoubleGauge;
-import io.opentelemetry.api.trace.Span;
-import io.opentelemetry.api.trace.SpanKind;
-import io.opentelemetry.api.trace.Tracer;
-import io.opentelemetry.context.Scope;
-import java.time.LocalDate;
-import java.time.Month;
-import java.time.format.DateTimeFormatter;
 import java.util.Map;
-import java.util.Random;
 import java.util.concurrent.atomic.AtomicLong;
+
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -27,62 +18,50 @@
 import org.springframework.web.bind.annotation.RequestHeader;
 import org.springframework.web.bind.annotation.RestController;
 
+import com.otel.service.CalendarService;
+
+import io.opentelemetry.api.OpenTelemetry;
+import io.opentelemetry.api.metrics.DoubleHistogram;
+import io.opentelemetry.api.metrics.LongCounter;
+import io.opentelemetry.api.metrics.Meter;
+import io.opentelemetry.api.metrics.ObservableDoubleGauge;
+
 @RestController
 public class CalendarController {
     private final Logger log = LoggerFactory.getLogger(CalendarController.class);
-    private final Tracer tracer;
     private final LongCounter hitsCounter;
     private final DoubleHistogram latency;
     private final ObservableDoubleGauge activeUsersGauge;
     private final AtomicLong activeUsersCounter;
-    private final Random random = new Random();
+    private final CalendarService calendarService;
 
     @Autowired
-    CalendarController(OpenTelemetry openTelemetry, String serviceName) {
+    CalendarController(OpenTelemetry openTelemetry, String serviceName, CalendarService service) {
         log.info("Starting CalendarController for {}", serviceName);
-        tracer = openTelemetry.getTracer(CalendarController.class.getName());
+
         Meter meter = openTelemetry.getMeter(CalendarController.class.getName());
         hitsCounter = meter.counterBuilder(serviceName + ".api.hits").build();
         latency = meter.histogramBuilder(serviceName + ".task.duration").build();
+
         activeUsersCounter = new AtomicLong();
-        activeUsersGauge = meter.gaugeBuilder(serviceName + ".active.users.guage").buildWithCallback(measurement -> measurement.record(activeUsersCounter.get()));
-
+        activeUsersGauge = meter.gaugeBuilder(serviceName + ".active.users.gauge").buildWithCallback(measurement -> measurement.record(activeUsersCounter.get()));
+
+        calendarService = service;
     }
 
-
     @GetMapping("/calendar")
     public Map<String, String> getDate(@RequestHeader MultiValueMap<String, String> headers) {
         long startTime = System.currentTimeMillis();
         activeUsersCounter.incrementAndGet();
+
         try {
             hitsCounter.add(1);
-            String output = getDate();
-            // the correct JSON output should put this in quotes. Spring does not, so let's put quotes here
-            // by hand.
+            String output = calendarService.getDate();
             return Map.of("date", output);
         } finally {
             long endTime = System.currentTimeMillis();
             latency.record(endTime - startTime);
             activeUsersCounter.decrementAndGet();
         }
     }
-
-    private String getDate() {
-        Span span = tracer.spanBuilder("getDate").setAttribute("peer.service", "random-date-service").setSpanKind(SpanKind.CLIENT).startSpan();
-        try (Scope scope = span.makeCurrent()) {
-            // get back a random date in the year 2022
-            int val = new Random().nextInt(365);
-            LocalDate start = LocalDate.of(2022, Month.JANUARY, 1).plusDays(val);
-            String output = start.format(DateTimeFormatter.ISO_LOCAL_DATE);
-            span.setAttribute("date", output);
-            // Add random sleep
-            Thread.sleep(random.nextLong(1,950));
-            log.info("generated date: {}", output);
-            return output;
-        } catch (InterruptedException e) {
-            throw new RuntimeException(e);
-        } finally {
-            span.end();
-        }
-    }
 }
diff --git a/apps/rest-services/java/calendar/src/main/java/com/otel/main/SpringApp.java b/apps/rest-services/java/calendar/src/main/java/com/otel/main/SpringApp.java
@@ -3,30 +3,31 @@
 under the Apache 2.0 License.
 
 This product includes software developed at Datadog (https://www.datadoghq.com/)
-Copyright 2023 Datadog, Inc.
- */
+Copyright 2024 Datadog, Inc.
+*/
 package com.otel.main;
 
-import io.opentelemetry.api.GlobalOpenTelemetry;
-import io.opentelemetry.api.OpenTelemetry;
-import org.springframework.beans.BeanUtils;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.context.annotation.Bean;
 
+import io.opentelemetry.api.GlobalOpenTelemetry;
+import io.opentelemetry.api.OpenTelemetry;
+
 @SpringBootApplication(scanBasePackages = "com.otel")
 public class SpringApp {
-  public static void main(String[] args) {
-    SpringApplication.run(SpringApp.class, args);
-  }
-  @Bean
-  public OpenTelemetry openTelemetry() {
-    return GlobalOpenTelemetry.get();
-  }
+    public static void main(String[] args) {
+        SpringApplication.run(SpringApp.class, args);
+    }
+
+    @Bean
+    public OpenTelemetry openTelemetry() {
+        return GlobalOpenTelemetry.get();
+    }
 
-  @Bean
-  public String serviceName() {
-    String serviceName = System.getProperty("otel.serviceName");
-    return   serviceName != null ? serviceName : "calendar";
-  }
+    @Bean
+    public String serviceName() {
+        String serviceName = System.getProperty("otel.service.name");
+        return serviceName != null ? serviceName : "calendar";
+    }
 }
diff --git a/apps/rest-services/java/calendar/src/main/java/com/otel/service/CalendarService.java b/apps/rest-services/java/calendar/src/main/java/com/otel/service/CalendarService.java
@@ -0,0 +1,49 @@
+/*
+Unless explicitly stated otherwise all files in this repository are licensed
+under the Apache 2.0 License.
+
+This product includes software developed at Datadog (https://www.datadoghq.com/)
+Copyright 2024 Datadog, Inc.
+*/
+package com.otel.service;
+
+import java.time.LocalDate;
+import java.time.format.DateTimeFormatter;
+import java.util.Random;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Component;
+
+import io.opentelemetry.api.trace.Span;
+import io.opentelemetry.api.trace.SpanKind;
+import io.opentelemetry.instrumentation.annotations.WithSpan;
+
+@Component
+public class CalendarService {
+    private final Logger log = LoggerFactory.getLogger(CalendarService.class);
+    private final Random random = new Random();
+
+    @WithSpan(kind = SpanKind.CLIENT)
+    public String getDate() {
+        Span span = Span.current();
+        span.setAttribute("peer.service", "random-date-service");
+
+        // generate a random day within current year
+        int day = new Random().nextInt(365);
+        LocalDate date = LocalDate.now().withDayOfYear(1 + day);
+        String output = date.format(DateTimeFormatter.ISO_LOCAL_DATE);
+
+        span.setAttribute("date", output);
+
+        try {
+            // add random sleep
+            Thread.sleep(random.nextLong(1, 950));
+        } catch (InterruptedException e) {
+            throw new RuntimeException(e);
+        }
+
+        log.info("generated date: {}", output);
+        return output;
+    }
+}