Allow OTLP HTTP exporter to also export in gRPC format.

open-telemetry · Sep 30, 2021 · abeefbc · abeefbc
1 parent 694ac3f
commit abeefbc
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Showing 7 changed files with 205 additions and 24 deletions.
diff --git a/dependencyManagement/build.gradle.kts b/dependencyManagement/build.gradle.kts
@@ -75,8 +75,8 @@ val DEPENDENCIES = listOf(
   // using old version of okhttp to avoid pulling in kotlin stdlib
   // not using (old) okhttp bom because that is pulling in old guava version
   // and overriding the guava bom
-  "com.squareup.okhttp3:okhttp:3.12.13",
-  "com.squareup.okhttp3:okhttp-tls:3.12.13",
+  "com.squareup.okhttp3:okhttp:3.14.9",
+  "com.squareup.okhttp3:okhttp-tls:3.14.9",
   "com.sun.net.httpserver:http:20070405",
   "com.tngtech.archunit:archunit-junit5:0.21.0",
   "com.uber.nullaway:nullaway:0.9.2",

diff --git a/...ics/src/main/java/io/opentelemetry/exporter/otlp/http/metrics/OtlpHttpMetricExporter.java b/...ics/src/main/java/io/opentelemetry/exporter/otlp/http/metrics/OtlpHttpMetricExporter.java
@@ -5,9 +5,9 @@
 
 package io.opentelemetry.exporter.otlp.http.metrics;
 
-import io.opentelemetry.exporter.otlp.internal.ProtoRequestBody;
 import io.opentelemetry.exporter.otlp.internal.grpc.GrpcStatusUtil;
 import io.opentelemetry.exporter.otlp.internal.metrics.MetricsRequestMarshaler;
+import io.opentelemetry.exporter.otlp.internal.okhttp.ProtoRequestBody;
 import io.opentelemetry.sdk.common.CompletableResultCode;
 import io.opentelemetry.sdk.internal.ThrottlingLogger;
 import io.opentelemetry.sdk.metrics.data.MetricData;

diff --git a/...p/trace/src/main/java/io/opentelemetry/exporter/otlp/http/trace/OtlpHttpSpanExporter.java b/...p/trace/src/main/java/io/opentelemetry/exporter/otlp/http/trace/OtlpHttpSpanExporter.java
@@ -10,8 +10,9 @@
 import io.opentelemetry.api.metrics.GlobalMeterProvider;
 import io.opentelemetry.api.metrics.LongCounter;
 import io.opentelemetry.api.metrics.Meter;
-import io.opentelemetry.exporter.otlp.internal.ProtoRequestBody;
 import io.opentelemetry.exporter.otlp.internal.grpc.GrpcStatusUtil;
+import io.opentelemetry.exporter.otlp.internal.okhttp.GrpcRequestBody;
+import io.opentelemetry.exporter.otlp.internal.okhttp.ProtoRequestBody;
 import io.opentelemetry.exporter.otlp.internal.traces.TraceRequestMarshaler;
 import io.opentelemetry.sdk.common.CompletableResultCode;
 import io.opentelemetry.sdk.internal.ThrottlingLogger;
@@ -21,7 +22,6 @@
 import java.util.Collection;
 import java.util.logging.Level;
 import java.util.logging.Logger;
-import javax.annotation.Nullable;
 import javax.annotation.concurrent.ThreadSafe;
 import okhttp3.Call;
 import okhttp3.Callback;
@@ -40,6 +40,9 @@
 @ThreadSafe
 public final class OtlpHttpSpanExporter implements SpanExporter {
 
+  private static final String GRPC_STATUS = "grpc-status";
+  private static final String GRPC_MESSAGE = "grpc-message";
+
   private static final String EXPORTER_NAME = OtlpHttpSpanExporter.class.getSimpleName();
   private static final Attributes EXPORTER_NAME_LABELS =
       Attributes.builder().put("exporter", EXPORTER_NAME).build();
@@ -59,11 +62,17 @@ public final class OtlpHttpSpanExporter implements SpanExporter {
 
   private final OkHttpClient client;
   private final String endpoint;
-  @Nullable private final Headers headers;
+  private final Headers headers;
   private final boolean compressionEnabled;
+  private final boolean useGrpc;
 
   OtlpHttpSpanExporter(
-      OkHttpClient client, String endpoint, @Nullable Headers headers, boolean compressionEnabled) {
+      OkHttpClient client,
+      String endpoint,
+      Headers headers,
+      boolean compressionEnabled,
+      boolean useGrpc) {
+    this.useGrpc = useGrpc;
     Meter meter = GlobalMeterProvider.get().get("io.opentelemetry.exporters.otlp-http");
     this.spansSeen = meter.counterBuilder("spansSeenByExporter").build().bind(EXPORTER_NAME_LABELS);
     LongCounter spansExportedCounter = meter.counterBuilder("spansExportedByExporter").build();
@@ -89,17 +98,19 @@ public CompletableResultCode export(Collection<SpanData> spans) {
     TraceRequestMarshaler exportRequest = TraceRequestMarshaler.create(spans);
 
     Request.Builder requestBuilder = new Request.Builder().url(endpoint);
-    if (headers != null) {
-      requestBuilder.headers(headers);
-    }
-    RequestBody requestBody = new ProtoRequestBody(exportRequest);
-    if (compressionEnabled) {
-      requestBuilder.addHeader("Content-Encoding", "gzip");
-      requestBuilder.post(gzipRequestBody(requestBody));
+    requestBuilder.headers(headers);
+    RequestBody requestBody;
+    if (!useGrpc) {
+      requestBody = new ProtoRequestBody(exportRequest);
+      if (compressionEnabled) {
+        requestBody = gzipRequestBody(requestBody);
+      }
     } else {
-      requestBuilder.post(requestBody);
+      requestBody = new GrpcRequestBody(exportRequest, compressionEnabled);
     }
 
+    requestBuilder.post(requestBody);
+
     CompletableResultCode result = new CompletableResultCode();
 
     client
@@ -118,7 +129,21 @@ public void onFailure(Call call, IOException e) {
 
               @Override
               public void onResponse(Call call, Response response) {
-                if (response.isSuccessful()) {
+                if (useGrpc) {
+                  // Response body is empty but must be consumed to access trailers.
+                  try {
+                    response.body().bytes();
+                  } catch (IOException e) {
+                    logger.log(
+                        Level.WARNING,
+                        "Failed to export spans, could not consume server response.",
+                        e);
+                    result.fail();
+                    return;
+                  }
+                }
+
+                if (isSuccessful(response)) {
                   spansExportedSuccess.add(spans.size());
                   result.succeed();
                   return;
@@ -142,6 +167,28 @@ public void onResponse(Call call, Response response) {
     return result;
   }
 
+  private boolean isSuccessful(Response response) {
+    if (!response.isSuccessful()) {
+      return false;
+    }
+
+    if (!useGrpc) {
+      return true;
+    }
+
+    // Status can either be in the headers or trailers depending on error
+    String grpcStatus = response.header(GRPC_STATUS);
+    if (grpcStatus == null) {
+      try {
+        grpcStatus = response.trailers().get(GRPC_STATUS);
+      } catch (IOException e) {
+        // Could not read a status so assume the request failed.
+        return false;
+      }
+    }
+    return "0".equals(grpcStatus);
+  }
+
   private static RequestBody gzipRequestBody(RequestBody requestBody) {
     return new RequestBody() {
       @Override
@@ -163,7 +210,23 @@ public void writeTo(BufferedSink bufferedSink) throws IOException {
     };
   }
 
-  private static String extractErrorStatus(Response response) {
+  private String extractErrorStatus(Response response) {
+    if (useGrpc) {
+      String message = response.header(GRPC_MESSAGE);
+      if (message == null) {
+        try {
+          message = response.trailers().get(GRPC_MESSAGE);
+        } catch (IOException e) {
+          // Fall through
+        }
+      }
+      if (message != null) {
+        return message;
+      }
+      // Couldn't get message for some reason, shouldn't happen in practice.
+      return "";
+    }
+
     ResponseBody responseBody = response.body();
     if (responseBody == null) {
       return "Response body missing, HTTP status message: " + response.message();

diff --git a/.../src/main/java/io/opentelemetry/exporter/otlp/http/trace/OtlpHttpSpanExporterBuilder.java b/.../src/main/java/io/opentelemetry/exporter/otlp/http/trace/OtlpHttpSpanExporterBuilder.java
@@ -12,23 +12,28 @@
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.time.Duration;
+import java.util.Collections;
 import java.util.concurrent.TimeUnit;
 import javax.annotation.Nullable;
 import javax.net.ssl.SSLException;
 import javax.net.ssl.X509TrustManager;
 import okhttp3.Headers;
 import okhttp3.OkHttpClient;
+import okhttp3.Protocol;
 
 /** Builder utility for {@link OtlpHttpSpanExporter}. */
 public final class OtlpHttpSpanExporterBuilder {
 
+  private static final String GRPC_ENDPOINT_PATH =
+      "/opentelemetry.proto.collector.trace.v1.TraceService/Export";
+
   private static final long DEFAULT_TIMEOUT_SECS = 10;
   private static final String DEFAULT_ENDPOINT = "http://localhost:4317/v1/traces";
 
   private long timeoutNanos = TimeUnit.SECONDS.toNanos(DEFAULT_TIMEOUT_SECS);
   private String endpoint = DEFAULT_ENDPOINT;
   private boolean compressionEnabled = false;
-  @Nullable private Headers.Builder headersBuilder;
+  private final Headers.Builder headersBuilder = new Headers.Builder();
   @Nullable private byte[] trustedCertificatesPem;
 
   /**
@@ -90,9 +95,6 @@ public OtlpHttpSpanExporterBuilder setCompression(String compressionMethod) {
 
   /** Add header to requests. */
   public OtlpHttpSpanExporterBuilder addHeader(String key, String value) {
-    if (headersBuilder == null) {
-      headersBuilder = new Headers.Builder();
-    }
     headersBuilder.add(key, value);
     return this;
   }
@@ -127,9 +129,28 @@ public OtlpHttpSpanExporter build() {
       }
     }
 
-    Headers headers = headersBuilder == null ? null : headersBuilder.build();
+    String endpoint = this.endpoint;
+
+    boolean useGrpc = endpoint.endsWith(GRPC_ENDPOINT_PATH);
+    if (useGrpc) {
+      if (endpoint.startsWith("http://")) {
+        clientBuilder.protocols(Collections.singletonList(Protocol.H2_PRIOR_KNOWLEDGE));
+      } else {
+        clientBuilder.protocols(Collections.singletonList(Protocol.HTTP_2));
+      }
+
+      headersBuilder.add("te", "trailers");
+      if (compressionEnabled) {
+        headersBuilder.add("grpc-encoding", "gzip");
+      }
+    } else if (compressionEnabled) {
+      headersBuilder.add("Content-Encoding", "gzip");
+    }
+
+    Headers headers = headersBuilder.build();
 
-    return new OtlpHttpSpanExporter(clientBuilder.build(), endpoint, headers, compressionEnabled);
+    return new OtlpHttpSpanExporter(
+        clientBuilder.build(), endpoint, headers, compressionEnabled, useGrpc);
   }
 
   OtlpHttpSpanExporterBuilder() {}

diff --git a/.../common/src/main/java/io/opentelemetry/exporter/otlp/internal/okhttp/GrpcRequestBody.java b/.../common/src/main/java/io/opentelemetry/exporter/otlp/internal/okhttp/GrpcRequestBody.java
@@ -0,0 +1,80 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.exporter.otlp.internal.okhttp;
+
+import io.opentelemetry.exporter.otlp.internal.Marshaler;
+import java.io.IOException;
+import javax.annotation.Nullable;
+import okhttp3.MediaType;
+import okhttp3.RequestBody;
+import okio.Buffer;
+import okio.BufferedSink;
+import okio.GzipSink;
+import okio.Okio;
+
+/**
+ * A {@link RequestBody} for reading from a {@link Marshaler} and writing in gRPC wire format.
+ *
+ * <p>This class is internal and is hence not for public use. Its APIs are unstable and can change
+ * at any time.
+ */
+public final class GrpcRequestBody extends RequestBody {
+
+  private static final int HEADER_LENGTH = 5;
+
+  private static final byte UNCOMPRESSED_FLAG = 0;
+  private static final byte COMPRESSED_FLAG = 1;
+
+  private static final MediaType GRPC_MEDIA_TYPE = MediaType.parse("application/grpc");
+
+  private final Marshaler marshaler;
+  private final int messageSize;
+  private final int contentLength;
+  private final boolean compressed;
+
+  /** Creates a new {@link GrpcRequestBody}. */
+  public GrpcRequestBody(Marshaler marshaler, boolean compressed) {
+    this.marshaler = marshaler;
+    this.compressed = compressed;
+
+    messageSize = marshaler.getBinarySerializedSize();
+    if (compressed) {
+      // Content length not known since we want to compress on the I/O thread.
+      contentLength = -1;
+    } else {
+      contentLength = HEADER_LENGTH + messageSize;
+    }
+  }
+
+  @Nullable
+  @Override
+  public MediaType contentType() {
+    return GRPC_MEDIA_TYPE;
+  }
+
+  @Override
+  public long contentLength() {
+    return contentLength;
+  }
+
+  @Override
+  public void writeTo(BufferedSink sink) throws IOException {
+    if (!compressed) {
+      sink.writeByte(UNCOMPRESSED_FLAG);
+      sink.writeInt(messageSize);
+      marshaler.writeBinaryTo(sink.outputStream());
+    } else {
+      Buffer compressedBody = new Buffer();
+      try (BufferedSink gzipSink = Okio.buffer(new GzipSink(compressedBody))) {
+        marshaler.writeBinaryTo(gzipSink.outputStream());
+      }
+      sink.writeByte(COMPRESSED_FLAG);
+      int compressedBytes = (int) compressedBody.size();
+      sink.writeInt(compressedBytes);
+      sink.write(compressedBody, compressedBytes);
+    }
+  }
+}
diff --git a/...orter/otlp/internal/ProtoRequestBody.java → ...tlp/internal/okhttp/ProtoRequestBody.java b/...orter/otlp/internal/ProtoRequestBody.java → ...tlp/internal/okhttp/ProtoRequestBody.java
@@ -3,8 +3,9 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-package io.opentelemetry.exporter.otlp.internal;
+package io.opentelemetry.exporter.otlp.internal.okhttp;
 
+import io.opentelemetry.exporter.otlp.internal.Marshaler;
 import java.io.IOException;
 import okhttp3.MediaType;
 import okhttp3.RequestBody;

diff --git a/integration-tests/src/test/java/io/opentelemetry/OtlpExporterIntegrationTest.java b/integration-tests/src/test/java/io/opentelemetry/OtlpExporterIntegrationTest.java
@@ -150,6 +150,22 @@ void testOtlpGrpcTraceExport() {
     testTraceExport(otlpGrpcTraceExporter);
   }
 
+  @Test
+  void testOtlpGrpcViaHttpTraceExport() {
+    SpanExporter otlpGrpcHttpTraceExporter =
+        OtlpHttpSpanExporter.builder()
+            .setEndpoint(
+                "http://"
+                    + collector.getHost()
+                    + ":"
+                    + collector.getMappedPort(COLLECTOR_OTLP_GRPC_PORT)
+                    + "/opentelemetry.proto.collector.trace.v1.TraceService/Export")
+            .setCompression("gzip")
+            .build();
+
+    testTraceExport(otlpGrpcHttpTraceExporter);
+  }
+
   @Test
   void testOtlpHttpTraceExport() {
     SpanExporter otlpGrpcTraceExporter =