High priority defaults for OtlpExporterRuntimeConfig

(cherry picked from commit 883b1ed)

extensions/opentelemetry/deployment/src/main/java/io/quarkus/opentelemetry/deployment/exporter/otlp/OtlpExporterProcessor.java

@@ -20,9 +20,11 @@
 import io.quarkus.arc.deployment.SyntheticBeanBuildItem;
 import io.quarkus.deployment.annotations.*;
 import io.quarkus.deployment.annotations.Record;
+import io.quarkus.deployment.builditem.RunTimeConfigBuilderBuildItem;
 import io.quarkus.opentelemetry.runtime.config.build.OTelBuildConfig;
 import io.quarkus.opentelemetry.runtime.config.build.exporter.OtlpExporterBuildConfig;
 import io.quarkus.opentelemetry.runtime.config.runtime.OTelRuntimeConfig;
+import io.quarkus.opentelemetry.runtime.config.runtime.exporter.OtlpExporterConfigBuilder;
 import io.quarkus.opentelemetry.runtime.config.runtime.exporter.OtlpExporterRuntimeConfig;
 import io.quarkus.opentelemetry.runtime.exporter.otlp.OTelExporterRecorder;
 import io.quarkus.opentelemetry.runtime.exporter.otlp.tracing.LateBoundBatchSpanProcessor;
@@ -59,6 +61,11 @@ public boolean getAsBoolean() {
         }
     }
 
+    @BuildStep
+    void config(BuildProducer<RunTimeConfigBuilderBuildItem> runTimeConfigBuilderProducer) {
+        runTimeConfigBuilderProducer.produce(new RunTimeConfigBuilderBuildItem(OtlpExporterConfigBuilder.class));
+    }
+
     @SuppressWarnings("deprecation")
     @BuildStep(onlyIf = OtlpExporterProcessor.OtlpTracingExporterEnabled.class)
     @Record(ExecutionTime.RUNTIME_INIT)

extensions/opentelemetry/runtime/src/main/java/io/quarkus/opentelemetry/runtime/config/OpenTelemetryConfigBuilderCustomizer.java → extensions/opentelemetry/runtime/src/main/java/io/quarkus/opentelemetry/runtime/config/runtime/exporter/OtlpExporterConfigBuilder.java

@@ -1,18 +1,34 @@
-package io.quarkus.opentelemetry.runtime.config;
+package io.quarkus.opentelemetry.runtime.config.runtime.exporter;
 
 import static io.quarkus.opentelemetry.runtime.config.runtime.exporter.OtlpExporterConfig.DEFAULT_GRPC_BASE_URI;
 import static io.quarkus.opentelemetry.runtime.config.runtime.exporter.OtlpExporterConfig.Protocol.GRPC;
 
 import java.util.HashMap;
 import java.util.Map;
 
+import io.quarkus.runtime.configuration.ConfigBuilder;
 import io.smallrye.config.FallbackConfigSourceInterceptor;
 import io.smallrye.config.SmallRyeConfigBuilder;
-import io.smallrye.config.SmallRyeConfigBuilderCustomizer;
 
-public class OpenTelemetryConfigBuilderCustomizer implements SmallRyeConfigBuilderCustomizer {
+/**
+ * Adds fallbacks to {@link OtlpExporterRuntimeConfig#traces()} and {@link OtlpExporterRuntimeConfig#metrics()} from
+ * the base configuration {@link OtlpExporterRuntimeConfig}. The goal is to fallback specific properties from either
+ * <code>tracer</code> or <code>metrics</code> to their parent configuration. For instance, if there is no value for
+ * <code>quarkus.otel.exporter.otlp.traces.endpoint</code> it fallbacks to
+ * <code>quarkus.otel.exporter.otlp.endpoint</code>.
+ * <p>
+ * Defaults are set using the {@link SmallRyeConfigBuilder#withDefaultValue(String, String)}, instead of
+ * {@link io.smallrye.config.WithDefault} because the mapping {@link OtlpExporterConfig} is shared between base
+ * (unnamed), <code>traces</code>, and <code>metrics</code>, which means that every path would always have a default,
+ * and it won't be possible to fallback from the specific configuration to the base configuration.
+ * <p>
+ * This builder is only set to customize the runtime configuration since the mapping {@link OtlpExporterRuntimeConfig}
+ * is only for runtime. The builder executes with a very high priority to ensure that it sets the default
+ * configuration early in the config setup to allow other configurations to override it (like Dev Services).
+ */
+public class OtlpExporterConfigBuilder implements ConfigBuilder {
     @Override
-    public void configBuilder(final SmallRyeConfigBuilder builder) {
+    public SmallRyeConfigBuilder configBuilder(final SmallRyeConfigBuilder builder) {
         // Main defaults
         builder.withDefaultValue("quarkus.otel.exporter.otlp.endpoint", DEFAULT_GRPC_BASE_URI);
         builder.withDefaultValue("quarkus.otel.exporter.otlp.protocol", GRPC);
@@ -60,6 +76,11 @@ public void configBuilder(final SmallRyeConfigBuilder builder) {
         fallbacks.put("quarkus.otel.exporter.otlp.metrics.proxy-options.host", "quarkus.otel.exporter.otlp.proxy-options.host");
         fallbacks.put("quarkus.otel.exporter.otlp.metrics.proxy-options.port", "quarkus.otel.exporter.otlp.proxy-options.port");
 
-        builder.withInterceptors(new FallbackConfigSourceInterceptor(fallbacks));
+        return builder.withInterceptors(new FallbackConfigSourceInterceptor(fallbacks));
+    }
+
+    @Override
+    public int priority() {
+        return Integer.MIN_VALUE;
     }
 }

extensions/opentelemetry/runtime/src/test/java/io/quarkus/opentelemetry/runtime/config/OpenTelemetryConfigTest.java

@@ -16,6 +16,7 @@
 
 import org.junit.jupiter.api.Test;
 
+import io.quarkus.opentelemetry.runtime.config.runtime.exporter.OtlpExporterConfigBuilder;
 import io.quarkus.opentelemetry.runtime.config.runtime.exporter.OtlpExporterMetricsConfig;
 import io.quarkus.opentelemetry.runtime.config.runtime.exporter.OtlpExporterRuntimeConfig;
 import io.quarkus.opentelemetry.runtime.config.runtime.exporter.OtlpExporterTracesConfig;
@@ -39,7 +40,7 @@ void fromBase() {
         baseExporterConfig.put("quarkus.otel.exporter.otlp.proxy-options.port", "9999");
 
         SmallRyeConfig config = new SmallRyeConfigBuilder()
-                .withCustomizers(new OpenTelemetryConfigBuilderCustomizer())
+                .withCustomizers(builder -> new OtlpExporterConfigBuilder().configBuilder(builder))
                 .withMapping(OtlpExporterRuntimeConfig.class)
                 .withDefaultValues(baseExporterConfig)
                 .build();
@@ -160,7 +161,7 @@ void overrideTraces() {
         tracesExporterConfig.put("quarkus.otel.exporter.otlp.traces.proxy-options.port", "6666");
 
         SmallRyeConfig config = new SmallRyeConfigBuilder()
-                .withCustomizers(new OpenTelemetryConfigBuilderCustomizer())
+                .withCustomizers(builder -> new OtlpExporterConfigBuilder().configBuilder(builder))
                 .withMapping(OtlpExporterRuntimeConfig.class)
                 .withDefaultValues(baseExporterConfig)
                 .withDefaultValues(tracesExporterConfig)