Added support for Otel TracerBuilder

CHANGELOG.asciidoc

@@ -35,6 +35,14 @@ Use subheadings with the "=====" level for adding notes for unreleased changes:
 ===== Features
 * Bumped base alpine docker image version - {pull}3524[#3524]
 
+[float]
+===== Bug fixes
+* Added missing support for TracerBuilder in OpenTelemetry bridge - {pull}3535[#3535]
+
+[float]
+===== Potentially breaking changes
+* The minimum supported OpenTelemetry version has been increased to 1.4.0 - {pull}3535[#3535]
+
 [[release-notes-1.x]]
 === Java Agent version 1.x
 

apm-agent-plugins/apm-opentelemetry/apm-opentelemetry-plugin/src/main/java/co/elastic/apm/agent/opentelemetry/AbstractOpenTelemetryInstrumentation.java

@@ -30,7 +30,9 @@ public abstract class AbstractOpenTelemetryInstrumentation extends ElasticApmIns
 
     @Override
     public ElementMatcher.Junction<ClassLoader> getClassLoaderMatcher() {
-        return classLoaderCanLoadClass("io.opentelemetry.context.propagation.TextMapSetter");
+        return classLoaderCanLoadClass("io.opentelemetry.context.propagation.TextMapSetter")
+            //TracerBuilder has been added in 1.4.0, which is the minimum supported API version
+            .and(classLoaderCanLoadClass("io.opentelemetry.api.trace.TracerBuilder"));
     }
 
     @Override

apm-agent-plugins/apm-opentelemetry/apm-opentelemetry-plugin/src/main/java/co/elastic/apm/agent/opentelemetry/tracing/OTelTracerProvider.java

@@ -19,6 +19,7 @@
 package co.elastic.apm.agent.opentelemetry.tracing;
 
 import io.opentelemetry.api.trace.Tracer;
+import io.opentelemetry.api.trace.TracerBuilder;
 import io.opentelemetry.api.trace.TracerProvider;
 
 import javax.annotation.Nullable;
@@ -39,4 +40,9 @@ public Tracer get(String instrumentationName) {
     public Tracer get(String instrumentationName, @Nullable String instrumentationVersion) {
         return this.tracer;
     }
+
+    @Override
+    public TracerBuilder tracerBuilder(String instrumentationScopeName) {
+        return new OtelTracerBuilder(tracer);
+    }
 }

apm-agent-plugins/apm-opentelemetry/apm-opentelemetry-plugin/src/main/java/co/elastic/apm/agent/opentelemetry/tracing/OtelTracerBuilder.java

@@ -0,0 +1,28 @@
+package co.elastic.apm.agent.opentelemetry.tracing;
+
+import io.opentelemetry.api.trace.Tracer;
+import io.opentelemetry.api.trace.TracerBuilder;
+
+public class OtelTracerBuilder implements TracerBuilder {
+
+    private final Tracer tracer;
+
+    public OtelTracerBuilder(Tracer tracer) {
+        this.tracer = tracer;
+    }
+
+    @Override
+    public TracerBuilder setSchemaUrl(String s) {
+        return this;
+    }
+
+    @Override
+    public TracerBuilder setInstrumentationVersion(String s) {
+        return this;
+    }
+
+    @Override
+    public Tracer build() {
+        return tracer;
+    }
+}

apm-agent-plugins/apm-opentelemetry/apm-opentelemetry-plugin/src/test/java/co/elastic/apm/agent/opentelemetry/tracing/ElasticOpenTelemetryTest.java

@@ -30,6 +30,7 @@
 import io.opentelemetry.api.trace.Span;
 import io.opentelemetry.api.trace.SpanKind;
 import io.opentelemetry.api.trace.StatusCode;
+import io.opentelemetry.api.trace.Tracer;
 import io.opentelemetry.context.Context;
 import io.opentelemetry.context.ContextKey;
 import io.opentelemetry.context.Scope;
@@ -81,6 +82,22 @@ public void testTransaction() {
             .isEqualTo(OTelSpanKind.INTERNAL);
     }
 
+    @Test
+    public void testTracerBuilder() {
+        Tracer tracer = openTelemetry.tracerBuilder("foo")
+            .setSchemaUrl("bar")
+            .setInstrumentationVersion("baz")
+            .build();
+
+        tracer.spanBuilder("transaction")
+            .startSpan()
+            .end();
+
+        assertThat(reporter.getTransactions()).hasSize(1);
+        Transaction transaction = reporter.getFirstTransaction();
+        assertThat(transaction.getNameAsString()).isEqualTo("transaction");
+    }
+
     @Test
     public void testTransactionWithAttribute() {
         otelTracer.spanBuilder("transaction")

apm-agent-plugins/apm-opentelemetry/apm-opentelemetry-test/src/test/java/co/elastic/apm/agent/opentelemetry/OpenTelemetryVersionIT.java

@@ -29,10 +29,7 @@ public class OpenTelemetryVersionIT {
 
     @ParameterizedTest
     @ValueSource(strings = {
-        "1.0.1",
-        "1.1.0",
-        "1.2.0",
-        "1.3.0",
+        "1.4.0",
         "1.4.1",
         "1.5.0",
         "1.6.0",

docs/api-opentelemetry.asciidoc

@@ -43,7 +43,7 @@ The first step in getting started with the OpenTelemetry API bridge is to declar
 compile "io.opentelemetry:opentelemetry-api:$openTelemetryVersion"
 ----
 
-The minimum required OpenTelemetry version is 1.0.1.
+The minimum required OpenTelemetry version is 1.4.0.
 
 [float]
 [[otel-init-tracer]]