Change default OTLP protocol to http/protobuf (#9993)

Co-authored-by: Trask Stalnaker <trask.stalnaker@gmail.com>

examples/distro/smoke-tests/src/test/java/com/example/javaagent/smoketest/SmokeTest.java

@@ -82,6 +82,9 @@ void startTarget(int jdk) {
             .withEnv("JAVA_TOOL_OPTIONS", "-javaagent:/opentelemetry-javaagent.jar")
             .withEnv("OTEL_BSP_MAX_EXPORT_BATCH", "1")
             .withEnv("OTEL_BSP_SCHEDULE_DELAY", "10")
+            // TODO (heya) update smoke tests to run using http/protobuf
+            // in the meantime, force smoke tests to use grpc protocol for all exporters
+            .withEnv("OTEL_EXPORTER_OTLP_PROTOCOL", "grpc")
             .withEnv("OTEL_PROPAGATORS", "tracecontext,baggage,demo")
             .withEnv(getExtraEnv())
             .waitingFor(getTargetWaitStrategy());

examples/extension/src/test/java/com/example/javaagent/smoketest/IntegrationTest.java

@@ -101,6 +101,9 @@ private GenericContainer<?> buildTargetContainer(String agentPath, String extens
             .withEnv("OTEL_BSP_MAX_EXPORT_BATCH", "1")
             .withEnv("OTEL_BSP_SCHEDULE_DELAY", "10")
             .withEnv("OTEL_PROPAGATORS", "tracecontext,baggage,demo")
+            // TODO (heya) update smoke tests to run using http/protobuf
+            // in the meantime, force smoke tests to use grpc protocol for all exporters
+            .withEnv("OTEL_EXPORTER_OTLP_PROTOCOL", "grpc")
             .withEnv(getExtraEnv())
             .waitingFor(getTargetWaitStrategy());
     // If external extensions are requested

javaagent-tooling/src/main/java/io/opentelemetry/javaagent/tooling/config/OtlpProtocolPropertiesSupplier.java

@@ -0,0 +1,27 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.javaagent.tooling.config;
+
+import com.google.auto.service.AutoService;
+import io.opentelemetry.sdk.autoconfigure.spi.AutoConfigurationCustomizer;
+import io.opentelemetry.sdk.autoconfigure.spi.AutoConfigurationCustomizerProvider;
+import java.util.Collections;
+
+@AutoService(AutoConfigurationCustomizerProvider.class)
+public class OtlpProtocolPropertiesSupplier implements AutoConfigurationCustomizerProvider {
+
+  @Override
+  public void customize(AutoConfigurationCustomizer autoConfigurationCustomizer) {
+    autoConfigurationCustomizer.addPropertiesSupplier(
+        () -> Collections.singletonMap("otel.exporter.otlp.protocol", "http/protobuf"));
+  }
+
+  @Override
+  public int order() {
+    // make sure it runs BEFORE all the user-provided customizers
+    return Integer.MIN_VALUE;
+  }
+}

javaagent-tooling/src/test/java/io/opentelemetry/javaagent/tooling/config/OtlpProtocolPropertiesSupplierTest.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.javaagent.tooling.config;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import io.opentelemetry.api.GlobalOpenTelemetry;
+import io.opentelemetry.api.events.GlobalEventEmitterProvider;
+import io.opentelemetry.javaagent.tooling.OpenTelemetryInstaller;
+import io.opentelemetry.sdk.autoconfigure.AutoConfiguredOpenTelemetrySdk;
+import io.opentelemetry.sdk.autoconfigure.internal.AutoConfigureUtil;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.Test;
+import org.junitpioneer.jupiter.SetSystemProperty;
+
+class OtlpProtocolPropertiesSupplierTest {
+
+  @AfterEach
+  void cleanUp() {
+    GlobalOpenTelemetry.resetForTest();
+    GlobalEventEmitterProvider.resetForTest();
+  }
+
+  @SetSystemProperty(
+      key = "otel.exporter.otlp.protocol",
+      value = "grpc") // user explicitly sets grpc
+  @Test
+  void keepUserOtlpProtocolConfiguration() {
+    // when
+    AutoConfiguredOpenTelemetrySdk autoConfiguredSdk =
+        OpenTelemetryInstaller.installOpenTelemetrySdk(this.getClass().getClassLoader());
+
+    // then
+    assertThat(
+            AutoConfigureUtil.getConfig(autoConfiguredSdk).getString("otel.exporter.otlp.protocol"))
+        .isEqualTo("grpc");
+  }
+
+  @Test
+  void defaultHttpProtobufOtlpProtocolConfiguration() {
+    // when
+    AutoConfiguredOpenTelemetrySdk autoConfiguredSdk =
+        OpenTelemetryInstaller.installOpenTelemetrySdk(this.getClass().getClassLoader());
+
+    // then
+    assertThat(
+            AutoConfigureUtil.getConfig(autoConfiguredSdk).getString("otel.exporter.otlp.protocol"))
+        .isEqualTo("http/protobuf");
+  }
+}

javaagent-tooling/src/test/resources/META-INF/services/io.opentelemetry.sdk.autoconfigure.spi.AutoConfigurationCustomizerProvider

@@ -1,2 +1,3 @@
 io.opentelemetry.javaagent.tooling.config.ConfigurationPropertiesSupplier
+io.opentelemetry.javaagent.tooling.config.OtlpProtocolPropertiesSupplier
 io.opentelemetry.javaagent.tooling.config.ConfigurationPropertiesSupplierTest$UserCustomPropertiesSupplier

smoke-tests/src/test/java/io/opentelemetry/smoketest/AbstractTestContainerManager.java

@@ -30,6 +30,11 @@ protected Map<String, String> getAgentEnvironment(
             // Liberty20Jdk11, Payara6Jdk11 and Payara6Jdk17 fail with
             // java.util.zip.ZipException: Invalid CEN header (invalid zip64 extra data field size)
             + " -Djdk.util.zip.disableZip64ExtraFieldValidation=true");
+
+    // TODO (heya) update smoke tests to run using http/protobuf
+    // in the meantime, force smoke tests to use grpc protocol for all exporters
+    environment.put("OTEL_EXPORTER_OTLP_PROTOCOL", "grpc");
+
     environment.put("OTEL_BSP_MAX_EXPORT_BATCH_SIZE", "1");
     environment.put("OTEL_BSP_SCHEDULE_DELAY", "10ms");
     environment.put("OTEL_METRIC_EXPORT_INTERVAL", "1000");