From d68cc83f614e1a45168dca7295c40168927d0ab6 Mon Sep 17 00:00:00 2001
From: jcarranzan <jcarranz@redhat.com>
Date: Tue, 22 Oct 2024 11:23:17 +0200
Subject: [PATCH] Add use of Dev Services wgth Grafana LGTM and Opentelemetry
 metrics

---
 opentelemetry-quickstart/pom.xml              |  9 +++++
 .../acme/opentelemetry/TracedResource.java    | 33 +++++++++++++++++++
 .../src/main/resources/application.properties |  8 +++--
 .../opentelemetry/TracedResourceTest.java     | 13 ++++++++
 4 files changed, 60 insertions(+), 3 deletions(-)

diff --git a/opentelemetry-quickstart/pom.xml b/opentelemetry-quickstart/pom.xml
index 670080ebd3..6eb29347d0 100644
--- a/opentelemetry-quickstart/pom.xml
+++ b/opentelemetry-quickstart/pom.xml
@@ -48,6 +48,15 @@
       <groupId>io.quarkus</groupId>
       <artifactId>quarkus-rest-client</artifactId>
     </dependency>
+    <dependency>
+      <groupId>io.quarkus</groupId>
+      <artifactId>quarkus-observability-devservices-lgtm</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>io.quarkus</groupId>
+      <artifactId>quarkus-opentelemetry-exporter-otlp</artifactId>
+      <version>3.9.5</version>
+    </dependency>
   </dependencies>
   <build>
     <plugins>
diff --git a/opentelemetry-quickstart/src/main/java/org/acme/opentelemetry/TracedResource.java b/opentelemetry-quickstart/src/main/java/org/acme/opentelemetry/TracedResource.java
index a59eb3a65b..ff775ee8f7 100644
--- a/opentelemetry-quickstart/src/main/java/org/acme/opentelemetry/TracedResource.java
+++ b/opentelemetry-quickstart/src/main/java/org/acme/opentelemetry/TracedResource.java
@@ -1,8 +1,14 @@
 package org.acme.opentelemetry;
 
+import com.google.common.util.concurrent.AtomicDouble;
+import io.opentelemetry.api.GlobalOpenTelemetry;
+import io.opentelemetry.api.metrics.Meter;
+import jakarta.annotation.PostConstruct;
+import jakarta.inject.Inject;
 import jakarta.ws.rs.GET;
 import jakarta.ws.rs.Path;
 import jakarta.ws.rs.Produces;
+import jakarta.ws.rs.QueryParam;
 import jakarta.ws.rs.core.Context;
 import jakarta.ws.rs.core.MediaType;
 import jakarta.ws.rs.core.UriInfo;
@@ -18,6 +24,20 @@ public class TracedResource {
     @Context
     UriInfo uriInfo;
 
+    private Meter meter;
+
+    private AtomicDouble xValue = new AtomicDouble(0.0);
+
+    @PostConstruct
+    public void init() {
+        meter = GlobalOpenTelemetry.getMeter("myservice");
+
+        meter.gaugeBuilder("service.xvalue")
+                .setDescription("Current value of X in the service")
+                .setUnit("units")
+                .buildWithCallback(measurement -> measurement.record(xValue.get()));
+    }
+
     @GET
     @Path("/hello")
     @Produces(MediaType.TEXT_PLAIN)
@@ -35,4 +55,17 @@ public String chain() {
                 .build(ResourceClient.class);
         return "chain -> " + resourceClient.hello();
     }
+
+    @GET
+    @Path("/metrics/set")
+    @Produces(MediaType.APPLICATION_JSON)
+    public String setMetric(@QueryParam("value") Double value) {
+        if (value == null) {
+            LOG.warn("Attempted to set metric without providing a value.");
+            return "{\"status\":\"failure\", \"message\":\"Value parameter is missing\"}";
+        }
+        xValue.set(value);
+        LOG.infof("Metric 'xvalue' set to: %f", value);
+        return "{\"status\":\"success\", \"xvalue\":" + value + "}";
+    }
 }
diff --git a/opentelemetry-quickstart/src/main/resources/application.properties b/opentelemetry-quickstart/src/main/resources/application.properties
index 9e25685f64..2e6a52b49a 100644
--- a/opentelemetry-quickstart/src/main/resources/application.properties
+++ b/opentelemetry-quickstart/src/main/resources/application.properties
@@ -1,5 +1,7 @@
 quarkus.application.name=myservice
-quarkus.otel.exporter.otlp.traces.endpoint=http://localhost:4317
+quarkus.opentelemetry.enabled=true
+quarkus.opentelemetry.tracer.enabled=true
+quarkus.opentelemetry.metrics.enabled=true
+quarkus.opentelemetry.exporter.otlp.endpoint=http://localhost:4317
 quarkus.otel.exporter.otlp.traces.headers=Authorization=Bearer my_secret
-quarkus.log.console.format=%d{HH:mm:ss} %-5p traceId=%X{traceId}, parentId=%X{parentId}, spanId=%X{spanId}, sampled=%X{sampled} [%c{2.}] (%t) %s%e%n
-
+quarkus.log.console.format=%d{HH:mm:ss} %-5p traceId=%X{traceId}, parentId=%X{parentId}, spanId=%X{spanId}, sampled=%X{sampled} [%c{2.}] (%t) %s%e%n
\ No newline at end of file
diff --git a/opentelemetry-quickstart/src/test/java/org/acme/opentelemetry/TracedResourceTest.java b/opentelemetry-quickstart/src/test/java/org/acme/opentelemetry/TracedResourceTest.java
index 9031c4ecb2..423e6e302e 100644
--- a/opentelemetry-quickstart/src/test/java/org/acme/opentelemetry/TracedResourceTest.java
+++ b/opentelemetry-quickstart/src/test/java/org/acme/opentelemetry/TracedResourceTest.java
@@ -28,4 +28,17 @@ public void testChainEndpoint() {
                 .body(is("chain -> hello"));
     }
 
+    @Test
+    public void testSetMetricEndpoint() {
+        Double testValue = 42.0;
+
+        given()
+                .queryParam("value", testValue)
+                .when().get("/metrics/set")
+                .then()
+                .statusCode(200)
+                .body("status", is("success"))
+                .body("xvalue", is(testValue.floatValue()));
+    }
+
 }