Add gRPC observation instrumentation

dependencies.gradle

@@ -16,6 +16,8 @@ def VERSIONS = [
 	// wavefront
 	'com.wavefront:wavefront-sdk-java:3.0.+',
 	'com.wavefront:wavefront-internal-reporter-java:1.7.+',
+	// gRPC
+	'io.grpc:grpc-api:latest.release',
 	// test
 	'org.assertj:assertj-core:latest.release',
 	'org.awaitility:awaitility:latest.release',

micrometer-tracing/build.gradle

@@ -14,6 +14,9 @@ dependencies {
 	optionalApi 'ch.qos.logback:logback-classic'
 	optionalApi 'org.apache.logging.log4j:log4j-core'
 
+	// gRPC
+	optionalApi 'io.grpc:grpc-api'
+
 	testImplementation 'org.junit.jupiter:junit-jupiter'
 	testImplementation 'org.assertj:assertj-core'
 	testImplementation 'org.mockito:mockito-core'

micrometer-tracing/src/main/java/io/micrometer/tracing/instrument/grpc/GrpcClientTracingObservationHandler.java

@@ -0,0 +1,42 @@
+package io.micrometer.tracing.instrument.grpc;
+
+import io.micrometer.common.util.internal.logging.InternalLogger;
+import io.micrometer.common.util.internal.logging.InternalLoggerFactory;
+import io.micrometer.core.instrument.binder.grpc.GrpcClientObservationContext;
+import io.micrometer.tracing.Span;
+import io.micrometer.tracing.Tracer;
+import io.micrometer.tracing.handler.PropagatingSenderTracingObservationHandler;
+import io.micrometer.tracing.handler.TracingObservationHandler;
+import io.micrometer.tracing.propagation.Propagator;
+
+import java.net.URI;
+
+/**
+ * {@link TracingObservationHandler} for gRPC in client side.
+ *
+ * @author Tadaya Tsuyukubo
+ */
+public class GrpcClientTracingObservationHandler
+        extends PropagatingSenderTracingObservationHandler<GrpcClientObservationContext> {
+
+    private static final InternalLogger log = InternalLoggerFactory
+            .getInstance(GrpcClientTracingObservationHandler.class);
+
+    public GrpcClientTracingObservationHandler(Tracer tracer, Propagator propagator) {
+        super(tracer, propagator);
+    }
+
+    @Override
+    public void customizeSenderSpan(GrpcClientObservationContext context, Span span) {
+        String authority = context.getAuthority();
+        try {
+            URI uri = new URI(null, authority, null, null, null);
+            span.remoteIpAndPort(uri.getHost(), uri.getPort());
+        }
+        catch (Exception ex) {
+            log.warn("Exception [{}], occurred while trying to parse the authority [{}] to host and port.", ex,
+                    authority);
+        }
+    }
+
+}

micrometer-tracing/src/main/java/io/micrometer/tracing/instrument/grpc/GrpcServerTracingObservationHandler.java

@@ -0,0 +1,45 @@
+package io.micrometer.tracing.instrument.grpc;
+
+import io.micrometer.common.util.internal.logging.InternalLogger;
+import io.micrometer.common.util.internal.logging.InternalLoggerFactory;
+import io.micrometer.core.instrument.binder.grpc.GrpcServerObservationContext;
+import io.micrometer.tracing.Span;
+import io.micrometer.tracing.Tracer;
+import io.micrometer.tracing.handler.PropagatingReceiverTracingObservationHandler;
+import io.micrometer.tracing.handler.TracingObservationHandler;
+import io.micrometer.tracing.propagation.Propagator;
+
+import java.net.URI;
+
+/**
+ * {@link TracingObservationHandler} for gRPC in server side.
+ *
+ * @author Tadaya Tsuyukubo
+ */
+public class GrpcServerTracingObservationHandler
+        extends PropagatingReceiverTracingObservationHandler<GrpcServerObservationContext> {
+
+    private static final InternalLogger log = InternalLoggerFactory
+            .getInstance(GrpcServerTracingObservationHandler.class);
+
+    public GrpcServerTracingObservationHandler(Tracer tracer, Propagator propagator) {
+        super(tracer, propagator);
+    }
+
+    @Override
+    public Span.Builder customizeExtractedSpan(GrpcServerObservationContext context, Span.Builder builder) {
+        String authority = context.getAuthority();
+        if (authority != null) {
+            try {
+                URI uri = new URI(null, authority, null, null, null);
+                builder.remoteIpAndPort(uri.getHost(), uri.getPort());
+            }
+            catch (Exception ex) {
+                log.warn("Exception [{}], occurred while trying to parse the authority [{}] to host and port.", ex,
+                        authority);
+            }
+        }
+        return builder;
+    }
+
+}

micrometer-tracing/src/test/java/io/micrometer/tracing/instrument/grpc/GrpcClientTracingObservationHandlerTests.java

@@ -0,0 +1,51 @@
+package io.micrometer.tracing.instrument.grpc;
+
+import io.micrometer.core.instrument.binder.grpc.GrpcClientObservationContext;
+import io.micrometer.tracing.Span;
+import io.micrometer.tracing.Tracer;
+import io.micrometer.tracing.propagation.Propagator;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+
+import java.util.stream.Stream;
+
+import static org.junit.jupiter.params.provider.Arguments.arguments;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+
+/**
+ * Tests for {@link GrpcClientTracingObservationHandler}.
+ *
+ * @author Tadaya Tsuyukubo
+ */
+class GrpcClientTracingObservationHandlerTests {
+
+    @ParameterizedTest
+    @MethodSource
+    void customizeSenderSpan(String authority, String host, int port) {
+        Tracer tracer = mock(Tracer.class);
+        Propagator propagator = mock(Propagator.class);
+        GrpcClientTracingObservationHandler handler = new GrpcClientTracingObservationHandler(tracer, propagator);
+
+        GrpcClientObservationContext context = new GrpcClientObservationContext((carrier, key, value) -> {
+        });
+        context.setAuthority(authority);
+
+        Span span = mock(Span.class);
+        handler.customizeSenderSpan(context, span);
+
+        verify(span).remoteIpAndPort(host, port);
+    }
+
+    static Stream<Arguments> customizeSenderSpan() {
+        // @formatter:off
+        return Stream.of(
+                arguments("io.micrometer.grpc:12345", "io.micrometer.grpc", 12345),
+                arguments("localhost:12345", "localhost", 12345),
+                arguments("localhost", "localhost", -1)
+        );
+        // @formatter:on
+    }
+
+}

micrometer-tracing/src/test/java/io/micrometer/tracing/instrument/grpc/GrpcServerTracingObservationHandlerTests.java

@@ -0,0 +1,65 @@
+package io.micrometer.tracing.instrument.grpc;
+
+import io.micrometer.core.instrument.binder.grpc.GrpcServerObservationContext;
+import io.micrometer.tracing.Span;
+import io.micrometer.tracing.Tracer;
+import io.micrometer.tracing.propagation.Propagator;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+
+import java.util.stream.Stream;
+
+import static org.junit.jupiter.params.provider.Arguments.arguments;
+import static org.mockito.Mockito.*;
+
+/**
+ * Tests for {@link GrpcServerTracingObservationHandler}.
+ *
+ * @author Tadaya Tsuyukubo
+ */
+class GrpcServerTracingObservationHandlerTests {
+
+    @ParameterizedTest
+    @MethodSource
+    void customizeExtractedSpan(String authority, String host, int port) {
+        Tracer tracer = mock(Tracer.class);
+        Propagator propagator = mock(Propagator.class);
+        GrpcServerTracingObservationHandler handler = new GrpcServerTracingObservationHandler(tracer, propagator);
+
+        GrpcServerObservationContext context = new GrpcServerObservationContext((carrier, key) -> null);
+        context.setAuthority(authority);
+
+        Span.Builder builder = mock(Span.Builder.class);
+        handler.customizeExtractedSpan(context, builder);
+
+        verify(builder).remoteIpAndPort(host, port);
+    }
+
+    @Test
+    void customizeExtractedSpanWithNull() {
+        Tracer tracer = mock(Tracer.class);
+        Propagator propagator = mock(Propagator.class);
+        GrpcServerTracingObservationHandler handler = new GrpcServerTracingObservationHandler(tracer, propagator);
+
+        GrpcServerObservationContext context = new GrpcServerObservationContext((carrier, key) -> null);
+        context.setAuthority(null);
+
+        Span.Builder builder = mock(Span.Builder.class);
+        handler.customizeExtractedSpan(context, builder);
+
+        verifyNoInteractions(builder);
+    }
+
+    static Stream<Arguments> customizeExtractedSpan() {
+        // @formatter:off
+        return Stream.of(
+                arguments("io.micrometer.grpc:12345", "io.micrometer.grpc", 12345),
+                arguments("localhost:12345", "localhost", 12345),
+                arguments("localhost", "localhost", -1)
+        );
+        // @formatter:on
+    }
+
+}