Change OTLP HTTP content_type default to binary (open-telemetry#2558)

CHANGELOG.md

@@ -15,6 +15,9 @@ Increment the:
 
 ## [Unreleased]
 
+* [SDK] Change OTLP HTTP content_type default to binary
+  [#2558](https://github.com/open-telemetry/opentelemetry-cpp/pull/2558)
+
 ## [1.14.1] 2024-02-23
 
 * [SDK] Restore Recordable API compatibility with versions < 1.14.0

exporters/otlp/BUILD

@@ -104,6 +104,7 @@ cc_library(
 cc_library(
     name = "otlp_http_client",
     srcs = [
+        "src/otlp_http.cc",
         "src/otlp_http_client.cc",
     ],
     hdrs = [

exporters/otlp/CMakeLists.txt

@@ -108,7 +108,8 @@ if(WITH_OTLP_GRPC)
 endif()
 
 if(WITH_OTLP_HTTP)
-  add_library(opentelemetry_exporter_otlp_http_client src/otlp_http_client.cc)
+  add_library(opentelemetry_exporter_otlp_http_client src/otlp_http.cc
+                                                      src/otlp_http_client.cc)
   set_target_properties(opentelemetry_exporter_otlp_http_client
                         PROPERTIES EXPORT_NAME otlp_http_client)
   set_target_version(opentelemetry_exporter_otlp_http_client)

exporters/otlp/include/opentelemetry/exporters/otlp/otlp_environment.h

@@ -41,6 +41,10 @@ std::string GetOtlpDefaultHttpTracesEndpoint();
 std::string GetOtlpDefaultHttpMetricsEndpoint();
 std::string GetOtlpDefaultHttpLogsEndpoint();
 
+std::string GetOtlpDefaultHttpTracesProtocol();
+std::string GetOtlpDefaultHttpMetricsProtocol();
+std::string GetOtlpDefaultHttpLogsProtocol();
+
 // Compatibility with OTELCPP 1.8.2
 inline std::string GetOtlpDefaultHttpEndpoint()
 {

exporters/otlp/include/opentelemetry/exporters/otlp/otlp_http.h

@@ -3,6 +3,8 @@
 
 #pragma once
 
+#include "opentelemetry/common/macros.h"
+#include "opentelemetry/nostd/string_view.h"
 #include "opentelemetry/sdk/version/version.h"
 
 OPENTELEMETRY_BEGIN_NAMESPACE
@@ -24,6 +26,9 @@ enum class HttpRequestContentType
   kBinary,
 };
 
+OPENTELEMETRY_EXPORT HttpRequestContentType
+GetOtlpHttpProtocolFromString(nostd::string_view name) noexcept;
+
 }  // namespace otlp
 }  // namespace exporter
 OPENTELEMETRY_END_NAMESPACE

exporters/otlp/include/opentelemetry/exporters/otlp/otlp_http_client.h

@@ -52,8 +52,8 @@ struct OtlpHttpClientOptions
   /** SSL options. */
   ext::http::client::HttpSslOptions ssl_options;
 
-  // By default, post json data
-  HttpRequestContentType content_type = HttpRequestContentType::kJson;
+  // By default, post binary data
+  HttpRequestContentType content_type = HttpRequestContentType::kBinary;
 
   // If convert bytes into hex. By default, we will convert all bytes but id into base64
   // This option is ignored if content_type is not kJson

exporters/otlp/src/otlp_environment.cc

@@ -207,6 +207,78 @@ std::string GetOtlpDefaultHttpLogsEndpoint()
   return kDefault;
 }
 
+std::string GetOtlpDefaultHttpTracesProtocol()
+{
+  constexpr char kSignalEnv[]  = "OTEL_EXPORTER_OTLP_TRACES_PROTOCOL";
+  constexpr char kGenericEnv[] = "OTEL_EXPORTER_OTLP_PROTOCOL";
+  constexpr char kDefault[]    = "http/protobuf";
+
+  std::string value;
+  bool exists;
+
+  exists = sdk_common::GetStringEnvironmentVariable(kSignalEnv, value);
+  if (exists)
+  {
+    return value;
+  }
+
+  exists = sdk_common::GetStringEnvironmentVariable(kGenericEnv, value);
+  if (exists)
+  {
+    return value;
+  }
+
+  return kDefault;
+}
+
+std::string GetOtlpDefaultHttpMetricsProtocol()
+{
+  constexpr char kSignalEnv[]  = "OTEL_EXPORTER_OTLP_METRICS_PROTOCOL";
+  constexpr char kGenericEnv[] = "OTEL_EXPORTER_OTLP_PROTOCOL";
+  constexpr char kDefault[]    = "http/protobuf";
+
+  std::string value;
+  bool exists;
+
+  exists = sdk_common::GetStringEnvironmentVariable(kSignalEnv, value);
+  if (exists)
+  {
+    return value;
+  }
+
+  exists = sdk_common::GetStringEnvironmentVariable(kGenericEnv, value);
+  if (exists)
+  {
+    return value;
+  }
+
+  return kDefault;
+}
+
+std::string GetOtlpDefaultHttpLogsProtocol()
+{
+  constexpr char kSignalEnv[]  = "OTEL_EXPORTER_OTLP_LOGS_PROTOCOL";
+  constexpr char kGenericEnv[] = "OTEL_EXPORTER_OTLP_PROTOCOL";
+  constexpr char kDefault[]    = "http/protobuf";
+
+  std::string value;
+  bool exists;
+
+  exists = sdk_common::GetStringEnvironmentVariable(kSignalEnv, value);
+  if (exists)
+  {
+    return value;
+  }
+
+  exists = sdk_common::GetStringEnvironmentVariable(kGenericEnv, value);
+  if (exists)
+  {
+    return value;
+  }
+
+  return kDefault;
+}
+
 bool GetOtlpDefaultGrpcTracesIsInsecure()
 {
   std::string endpoint = GetOtlpDefaultGrpcTracesEndpoint();

exporters/otlp/src/otlp_http.cc

@@ -0,0 +1,26 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+#include "opentelemetry/exporters/otlp/otlp_http.h"
+
+OPENTELEMETRY_BEGIN_NAMESPACE
+namespace exporter
+{
+namespace otlp
+{
+
+HttpRequestContentType GetOtlpHttpProtocolFromString(nostd::string_view name) noexcept
+{
+  if (name == "http/json")
+  {
+    return HttpRequestContentType::kJson;
+  }
+  else
+  {
+    return HttpRequestContentType::kBinary;
+  }
+}
+
+}  // namespace otlp
+}  // namespace exporter
+OPENTELEMETRY_END_NAMESPACE

exporters/otlp/src/otlp_http_exporter_options.cc

@@ -17,7 +17,7 @@ namespace otlp
 OtlpHttpExporterOptions::OtlpHttpExporterOptions()
 {
   url                = GetOtlpDefaultHttpTracesEndpoint();
-  content_type       = HttpRequestContentType::kJson;
+  content_type       = GetOtlpHttpProtocolFromString(GetOtlpDefaultHttpTracesProtocol());
   json_bytes_mapping = JsonBytesMappingKind::kHexId;
   use_json_name      = false;
   console_debug      = false;

exporters/otlp/src/otlp_http_log_record_exporter_options.cc

@@ -17,7 +17,7 @@ namespace otlp
 OtlpHttpLogRecordExporterOptions::OtlpHttpLogRecordExporterOptions()
 {
   url                = GetOtlpDefaultHttpLogsEndpoint();
-  content_type       = HttpRequestContentType::kJson;
+  content_type       = GetOtlpHttpProtocolFromString(GetOtlpDefaultHttpLogsProtocol());
   json_bytes_mapping = JsonBytesMappingKind::kHexId;
   use_json_name      = false;
   console_debug      = false;

exporters/otlp/src/otlp_http_metric_exporter_options.cc

@@ -17,7 +17,7 @@ namespace otlp
 OtlpHttpMetricExporterOptions::OtlpHttpMetricExporterOptions()
 {
   url                     = GetOtlpDefaultMetricsEndpoint();
-  content_type            = HttpRequestContentType::kJson;
+  content_type            = GetOtlpHttpProtocolFromString(GetOtlpDefaultHttpMetricsProtocol());
   json_bytes_mapping      = JsonBytesMappingKind::kHexId;
   use_json_name           = false;
   console_debug           = false;

exporters/otlp/test/otlp_http_exporter_test.cc

@@ -522,6 +522,12 @@ TEST_F(OtlpHttpExporterTestPeer, ConfigJsonBytesMappingTest)
   EXPECT_EQ(GetOptions(exporter).json_bytes_mapping, JsonBytesMappingKind::kHex);
 }
 
+TEST(OtlpHttpExporterTest, ConfigDefaultProtocolTest)
+{
+  OtlpHttpExporterOptions opts;
+  EXPECT_EQ(opts.content_type, HttpRequestContentType::kBinary);
+}
+
 #  ifndef NO_GETENV
 // Test exporter configuration options with use_ssl_credentials
 TEST_F(OtlpHttpExporterTestPeer, ConfigFromEnv)
@@ -531,6 +537,7 @@ TEST_F(OtlpHttpExporterTestPeer, ConfigFromEnv)
   setenv("OTEL_EXPORTER_OTLP_TIMEOUT", "20s", 1);
   setenv("OTEL_EXPORTER_OTLP_HEADERS", "k1=v1,k2=v2", 1);
   setenv("OTEL_EXPORTER_OTLP_TRACES_HEADERS", "k1=v3,k1=v4", 1);
+  setenv("OTEL_EXPORTER_OTLP_PROTOCOL", "http/json", 1);
 
   std::unique_ptr<OtlpHttpExporter> exporter(new OtlpHttpExporter());
   EXPECT_EQ(GetOptions(exporter).url, url);
@@ -557,11 +564,13 @@ TEST_F(OtlpHttpExporterTestPeer, ConfigFromEnv)
     ++range.first;
     EXPECT_TRUE(range.first == range.second);
   }
+  EXPECT_EQ(GetOptions(exporter).content_type, HttpRequestContentType::kJson);
 
   unsetenv("OTEL_EXPORTER_OTLP_ENDPOINT");
   unsetenv("OTEL_EXPORTER_OTLP_TIMEOUT");
   unsetenv("OTEL_EXPORTER_OTLP_HEADERS");
   unsetenv("OTEL_EXPORTER_OTLP_TRACES_HEADERS");
+  unsetenv("OTEL_EXPORTER_OTLP_PROTOCOL");
 }
 
 TEST_F(OtlpHttpExporterTestPeer, ConfigFromTracesEnv)
@@ -571,6 +580,7 @@ TEST_F(OtlpHttpExporterTestPeer, ConfigFromTracesEnv)
   setenv("OTEL_EXPORTER_OTLP_TRACES_TIMEOUT", "1eternity", 1);
   setenv("OTEL_EXPORTER_OTLP_HEADERS", "k1=v1,k2=v2", 1);
   setenv("OTEL_EXPORTER_OTLP_TRACES_HEADERS", "k1=v3,k1=v4", 1);
+  setenv("OTEL_EXPORTER_OTLP_TRACES_PROTOCOL", "http/json", 1);
 
   std::unique_ptr<OtlpHttpExporter> exporter(new OtlpHttpExporter());
   EXPECT_EQ(GetOptions(exporter).url, url);
@@ -597,11 +607,13 @@ TEST_F(OtlpHttpExporterTestPeer, ConfigFromTracesEnv)
     ++range.first;
     EXPECT_TRUE(range.first == range.second);
   }
+  EXPECT_EQ(GetOptions(exporter).content_type, HttpRequestContentType::kJson);
 
   unsetenv("OTEL_EXPORTER_OTLP_TRACES_ENDPOINT");
   unsetenv("OTEL_EXPORTER_OTLP_TRACES_TIMEOUT");
   unsetenv("OTEL_EXPORTER_OTLP_HEADERS");
   unsetenv("OTEL_EXPORTER_OTLP_TRACES_HEADERS");
+  unsetenv("OTEL_EXPORTER_OTLP_TRACES_PROTOCOL");
 }
 #  endif
 

exporters/otlp/test/otlp_http_log_record_exporter_test.cc

@@ -642,6 +642,12 @@ TEST_F(OtlpHttpLogRecordExporterTestPeer, ConfigJsonBytesMappingTest)
   EXPECT_EQ(GetOptions(exporter).json_bytes_mapping, JsonBytesMappingKind::kHex);
 }
 
+TEST(OtlpHttpLogRecordExporterTest, ConfigDefaultProtocolTest)
+{
+  OtlpHttpLogRecordExporterOptions opts;
+  EXPECT_EQ(opts.content_type, HttpRequestContentType::kBinary);
+}
+
 #  ifndef NO_GETENV
 // Test exporter configuration options with use_ssl_credentials
 TEST_F(OtlpHttpLogRecordExporterTestPeer, ConfigFromEnv)
@@ -651,6 +657,7 @@ TEST_F(OtlpHttpLogRecordExporterTestPeer, ConfigFromEnv)
   setenv("OTEL_EXPORTER_OTLP_TIMEOUT", "20s", 1);
   setenv("OTEL_EXPORTER_OTLP_HEADERS", "k1=v1,k2=v2", 1);
   setenv("OTEL_EXPORTER_OTLP_LOGS_HEADERS", "k1=v3,k1=v4", 1);
+  setenv("OTEL_EXPORTER_OTLP_PROTOCOL", "http/json", 1);
 
   std::unique_ptr<OtlpHttpLogRecordExporter> exporter(new OtlpHttpLogRecordExporter());
   EXPECT_EQ(GetOptions(exporter).url, url);
@@ -677,11 +684,13 @@ TEST_F(OtlpHttpLogRecordExporterTestPeer, ConfigFromEnv)
     ++range.first;
     EXPECT_TRUE(range.first == range.second);
   }
+  EXPECT_EQ(GetOptions(exporter).content_type, HttpRequestContentType::kJson);
 
   unsetenv("OTEL_EXPORTER_OTLP_ENDPOINT");
   unsetenv("OTEL_EXPORTER_OTLP_TIMEOUT");
   unsetenv("OTEL_EXPORTER_OTLP_HEADERS");
   unsetenv("OTEL_EXPORTER_OTLP_LOGS_HEADERS");
+  unsetenv("OTEL_EXPORTER_OTLP_PROTOCOL");
 }
 
 TEST_F(OtlpHttpLogRecordExporterTestPeer, ConfigFromLogsEnv)
@@ -691,6 +700,7 @@ TEST_F(OtlpHttpLogRecordExporterTestPeer, ConfigFromLogsEnv)
   setenv("OTEL_EXPORTER_OTLP_LOGS_TIMEOUT", "20s", 1);
   setenv("OTEL_EXPORTER_OTLP_HEADERS", "k1=v1,k2=v2", 1);
   setenv("OTEL_EXPORTER_OTLP_LOGS_HEADERS", "k1=v3,k1=v4", 1);
+  setenv("OTEL_EXPORTER_OTLP_LOGS_PROTOCOL", "http/json", 1);
 
   std::unique_ptr<OtlpHttpLogRecordExporter> exporter(new OtlpHttpLogRecordExporter());
   EXPECT_EQ(GetOptions(exporter).url, url);
@@ -717,11 +727,13 @@ TEST_F(OtlpHttpLogRecordExporterTestPeer, ConfigFromLogsEnv)
     ++range.first;
     EXPECT_TRUE(range.first == range.second);
   }
+  EXPECT_EQ(GetOptions(exporter).content_type, HttpRequestContentType::kJson);
 
   unsetenv("OTEL_EXPORTER_OTLP_LOGS_ENDPOINT");
   unsetenv("OTEL_EXPORTER_OTLP_LOGS_TIMEOUT");
   unsetenv("OTEL_EXPORTER_OTLP_HEADERS");
   unsetenv("OTEL_EXPORTER_OTLP_LOGS_HEADERS");
+  unsetenv("OTEL_EXPORTER_OTLP_LOGS_PROTOCOL");
 }
 
 TEST_F(OtlpHttpLogRecordExporterTestPeer, DefaultEndpoint)

exporters/otlp/test/otlp_http_metric_exporter_test.cc

@@ -862,6 +862,12 @@ TEST_F(OtlpHttpMetricExporterTestPeer, ConfigJsonBytesMappingTest)
   google::protobuf::ShutdownProtobufLibrary();
 }
 
+TEST(OtlpHttpMetricExporterTest, ConfigDefaultProtocolTest)
+{
+  OtlpHttpMetricExporterOptions opts;
+  EXPECT_EQ(opts.content_type, HttpRequestContentType::kBinary);
+}
+
 #ifndef NO_GETENV
 // Test exporter configuration options with use_ssl_credentials
 TEST_F(OtlpHttpMetricExporterTestPeer, ConfigFromEnv)
@@ -871,6 +877,7 @@ TEST_F(OtlpHttpMetricExporterTestPeer, ConfigFromEnv)
   setenv("OTEL_EXPORTER_OTLP_TIMEOUT", "20s", 1);
   setenv("OTEL_EXPORTER_OTLP_HEADERS", "k1=v1,k2=v2", 1);
   setenv("OTEL_EXPORTER_OTLP_METRICS_HEADERS", "k1=v3,k1=v4", 1);
+  setenv("OTEL_EXPORTER_OTLP_PROTOCOL", "http/json", 1);
 
   std::unique_ptr<OtlpHttpMetricExporter> exporter(new OtlpHttpMetricExporter());
   EXPECT_EQ(GetOptions(exporter).url, url);
@@ -897,11 +904,13 @@ TEST_F(OtlpHttpMetricExporterTestPeer, ConfigFromEnv)
     ++range.first;
     EXPECT_TRUE(range.first == range.second);
   }
+  EXPECT_EQ(GetOptions(exporter).content_type, HttpRequestContentType::kJson);
 
   unsetenv("OTEL_EXPORTER_OTLP_ENDPOINT");
   unsetenv("OTEL_EXPORTER_OTLP_TIMEOUT");
   unsetenv("OTEL_EXPORTER_OTLP_HEADERS");
   unsetenv("OTEL_EXPORTER_OTLP_METRICS_HEADERS");
+  unsetenv("OTEL_EXPORTER_OTLP_PROTOCOL");
 }
 
 TEST_F(OtlpHttpMetricExporterTestPeer, ConfigFromMetricsEnv)
@@ -911,6 +920,7 @@ TEST_F(OtlpHttpMetricExporterTestPeer, ConfigFromMetricsEnv)
   setenv("OTEL_EXPORTER_OTLP_METRICS_TIMEOUT", "20s", 1);
   setenv("OTEL_EXPORTER_OTLP_HEADERS", "k1=v1,k2=v2", 1);
   setenv("OTEL_EXPORTER_OTLP_METRICS_HEADERS", "k1=v3,k1=v4", 1);
+  setenv("OTEL_EXPORTER_OTLP_METRICS_PROTOCOL", "http/json", 1);
 
   std::unique_ptr<OtlpHttpMetricExporter> exporter(new OtlpHttpMetricExporter());
   EXPECT_EQ(GetOptions(exporter).url, url);
@@ -937,11 +947,13 @@ TEST_F(OtlpHttpMetricExporterTestPeer, ConfigFromMetricsEnv)
     ++range.first;
     EXPECT_TRUE(range.first == range.second);
   }
+  EXPECT_EQ(GetOptions(exporter).content_type, HttpRequestContentType::kJson);
 
   unsetenv("OTEL_EXPORTER_OTLP_METRICS_ENDPOINT");
   unsetenv("OTEL_EXPORTER_OTLP_METRICS_TIMEOUT");
   unsetenv("OTEL_EXPORTER_OTLP_HEADERS");
   unsetenv("OTEL_EXPORTER_OTLP_METRICS_HEADERS");
+  unsetenv("OTEL_EXPORTER_OTLP_METRICS_PROTOCOL");
 }
 
 TEST_F(OtlpHttpMetricExporterTestPeer, DefaultEndpoint)