Add OTLP/HTTP+JSON Protocol exporter (#810)

CHANGELOG.md

@@ -15,6 +15,9 @@ Increment the:
 
 ## [Unreleased]
 
+* [EXPORTER] Add OTLP/HTTP+JSON Protocol exporter ([#810](https://github.com/open-telemetry/opentelemetry-cpp/pull/810))
+* [EXPORTER] Rename `OtlpExporter` to `OtlpGrpcExporter`, rename `otlp_exporter.h` to `otlp_grpc_exporter.h` ([#810](https://github.com/open-telemetry/opentelemetry-cpp/pull/810))
+
 ## [1.0.0-rc1] 2021-06-04
 
 * [BUILD] Enable Jaeger exporter build in Windows ([#815](https://github.com/open-telemetry/opentelemetry-cpp/pull/815))

CMakeLists.txt

@@ -203,7 +203,7 @@ if(WITH_OTLP)
       find_package(Protobuf REQUIRED)
     endif()
     if(NOT gRPC_FOUND)
-      find_package(gRPC REQUIRED)
+      find_package(gRPC)
     endif()
     if(WIN32)
       # Always use x64 protoc.exe
@@ -221,6 +221,15 @@ if(WITH_OTLP)
   message("PROTOBUF_PROTOC_EXECUTABLE=${PROTOBUF_PROTOC_EXECUTABLE}")
 
   include(cmake/opentelemetry-proto.cmake)
+  include(CMakeDependentOption)
+  find_package(CURL)
+  find_package(nlohmann_json)
+  cmake_dependent_option(
+    WITH_OTLP_GRPC "Whether to include the OTLP gRPC exporter in the SDK" ON
+    "gRPC_FOUND" OFF)
+  cmake_dependent_option(
+    WITH_OTLP_HTTP "Whether to include the OTLP http exporter in the SDK" ON
+    "CURL_FOUND;nlohmann_json_FOUND" OFF)
 endif()
 
 list(APPEND CMAKE_PREFIX_PATH "${CMAKE_BINARY_DIR}")
@@ -268,11 +277,11 @@ if(NOT WITH_API_ONLY)
   include_directories(ext/include)
 
   add_subdirectory(sdk)
+  add_subdirectory(ext)
   add_subdirectory(exporters)
   if(WITH_EXAMPLES)
     add_subdirectory(examples)
   endif()
-  add_subdirectory(ext)
 endif()
 
 # Add nlohmann/json submodule to include directories

WORKSPACE

@@ -29,9 +29,9 @@ load("@com_github_grpc_grpc//bazel:grpc_extra_deps.bzl", "grpc_extra_deps")
 
 grpc_extra_deps()
 
-load("@upb//bazel:repository_defs.bzl", "bazel_version_repository")
+load("@upb//bazel:workspace_deps.bzl", "upb_deps")
 
-bazel_version_repository(name = "upb_bazel_version")
+upb_deps()
 
 # Load prometheus C++ dependencies.
 load("@com_github_jupp0r_prometheus_cpp//bazel:repositories.bzl", "prometheus_cpp_repositories")

bazel/repository.bzl

@@ -29,13 +29,23 @@ def opentelemetry_cpp_deps():
     )
 
     # Load gRPC dependency
+    maybe(
+        http_archive,
+        name = "com_github_grpc_grpc_legacy",
+        sha256 = "2060769f2d4b0d3535ba594b2ab614d7f68a492f786ab94b4318788d45e3278a",
+        strip_prefix = "grpc-1.33.2",
+        urls = [
+            "https://github.com/grpc/grpc/archive/v1.33.2.tar.gz",
+        ],
+    )
+
     maybe(
         http_archive,
         name = "com_github_grpc_grpc",
-        sha256 = "d6277f77e0bb922d3f6f56c0f93292bb4cfabfc3c92b31ee5ccea0e100303612",
-        strip_prefix = "grpc-1.28.0",
+        sha256 = "2060769f2d4b0d3535ba594b2ab614d7f68a492f786ab94b4318788d45e3278a",
+        strip_prefix = "grpc-1.33.2",
         urls = [
-            "https://github.com/grpc/grpc/archive/v1.28.0.tar.gz",
+            "https://github.com/grpc/grpc/archive/v1.33.2.tar.gz",
         ],
     )
 

examples/CMakeLists.txt

@@ -1,4 +1,4 @@
-if(WITH_OTLP)
+if(WITH_OTLP_GRPC OR WITH_OTLP_HTTP)
   add_subdirectory(otlp)
   add_subdirectory(grpc)
 endif()

examples/otlp/BUILD

@@ -12,14 +12,27 @@ cc_library(
 )
 
 cc_binary(
-    name = "example_otlp",
+    name = "example_otlp_grpc",
     srcs = [
-        "main.cc",
+        "grpc_main.cc",
     ],
     deps = [
         ":foo_library",
         "//api",
-        "//exporters/otlp:otlp_exporter",
+        "//exporters/otlp:otlp_grpc_exporter",
+        "//sdk/src/trace",
+    ],
+)
+
+cc_binary(
+    name = "example_otlp_http",
+    srcs = [
+        "http_main.cc",
+    ],
+    deps = [
+        ":foo_library",
+        "//api",
+        "//exporters/otlp:otlp_http_exporter",
         "//sdk/src/trace",
     ],
 )

examples/otlp/CMakeLists.txt

@@ -6,12 +6,21 @@ add_library(otlp_foo_library foo_library/foo_library.cc)
 target_link_libraries(otlp_foo_library ${CMAKE_THREAD_LIBS_INIT}
                       ${CORE_RUNTIME_LIBS} opentelemetry_api)
 
-add_executable(example_otlp main.cc)
-target_link_libraries(
-  example_otlp
-  ${CMAKE_THREAD_LIBS_INIT}
-  otlp_foo_library
-  opentelemetry_trace
-  ${CORE_RUNTIME_LIBS}
-  opentelemetry_exporter_otprotocol
-  gRPC::grpc++)
+if(WITH_OTLP_GRPC)
+  add_executable(example_otlp_grpc grpc_main.cc)
+  target_link_libraries(
+    example_otlp_grpc
+    ${CMAKE_THREAD_LIBS_INIT}
+    otlp_foo_library
+    opentelemetry_trace
+    ${CORE_RUNTIME_LIBS}
+    opentelemetry_exporter_otlp_grpc
+    gRPC::grpc++)
+endif()
+
+if(WITH_OTLP_HTTP)
+  add_executable(example_otlp_http http_main.cc)
+  target_link_libraries(
+    example_otlp_http ${CMAKE_THREAD_LIBS_INIT} otlp_foo_library
+    opentelemetry_trace ${CORE_RUNTIME_LIBS} opentelemetry_exporter_otlp_http)
+endif()

examples/otlp/README.md

@@ -4,15 +4,16 @@ This is an example of how to use the [OpenTelemetry
 Protocol](https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/protocol/README.md)
 (OTLP) exporter.
 
-The application in `main.cc` initializes an `OtlpExporter` instance and uses it
-to register a tracer provider from the [OpenTelemetry
+The application in `grpc_main.cc` initializes an `OtlpGrpcExporter` instance and
+the application in `http_main.cc` initializes an `OtlpHttpExporter` instance
+and they register a tracer provider from the [OpenTelemetry
 SDK](https://github.com/open-telemetry/opentelemetry-cpp). The application then
 calls a `foo_library` which has been instrumented using the [OpenTelemetry
 API](https://github.com/open-telemetry/opentelemetry-cpp/tree/main/api).
 
 To enable TLS authentication for OTLP grpc exporter, SslCredentials can be used
 by specifying the path to client certificate pem file, or the string containing
-this certificate via OtlpExporterOptions. The path to such a .pem file can be
+this certificate via OtlpGrpcExporterOptions. The path to such a .pem file can be
 provided as a command-line argument alongwith the collector endpoint to the main
 binary invocation above.
 
@@ -31,18 +32,19 @@ OpenTelemetry Collector with an OTLP receiver by running:
 - On Unix based systems use:
 
 ```console
-docker run --rm -it -p 4317:4317 -v $(pwd)/examples/otlp:/cfg otel/opentelemetry-collector:0.19.0 --config=/cfg/opentelemetry-collector-config/config.dev.yaml
+docker run --rm -it -p 4317:4317 -p 55681:55681 -v $(pwd)/examples/otlp:/cfg otel/opentelemetry-collector:0.19.0 --config=/cfg/opentelemetry-collector-config/config.dev.yaml
 ```
 
 - On Windows use:
 
 ```console
-docker run --rm -it -p 4317:4317 -v "%cd%/examples/otlp":/cfg otel/opentelemetry-collector:0.19.0 --config=/cfg/opentelemetry-collector-config/config.dev.yaml
+docker run --rm -it -p 4317:4317 -p 55681:55681 -v "%cd%/examples/otlp":/cfg otel/opentelemetry-collector:0.19.0 --config=/cfg/opentelemetry-collector-config/config.dev.yaml
 ```
 
 Note that the OTLP exporter connects to the Collector at `localhost:4317` by
 default. This can be changed with first argument from command-line, for example:
-`./example_otlp gateway.docker.internal:4317`.
+`./example_otlp_grpc gateway.docker.internal:4317` and
+`./example_otlp_http gateway.docker.internal:55681/v1/traces`.
 
 Once you have the Collector running, see
 [CONTRIBUTING.md](../../CONTRIBUTING.md) for instructions on building and

examples/otlp/main.cc → examples/otlp/grpc_main.cc

@@ -1,7 +1,7 @@
 // Copyright The OpenTelemetry Authors
 // SPDX-License-Identifier: Apache-2.0
 
-#include "opentelemetry/exporters/otlp/otlp_exporter.h"
+#include "opentelemetry/exporters/otlp/otlp_grpc_exporter.h"
 #include "opentelemetry/sdk/trace/simple_processor.h"
 #include "opentelemetry/sdk/trace/tracer_provider.h"
 #include "opentelemetry/trace/provider.h"
@@ -15,11 +15,11 @@ namespace otlp     = opentelemetry::exporter::otlp;
 
 namespace
 {
-opentelemetry::exporter::otlp::OtlpExporterOptions opts;
+opentelemetry::exporter::otlp::OtlpGrpcExporterOptions opts;
 void InitTracer()
 {
   // Create OTLP exporter instance
-  auto exporter  = std::unique_ptr<sdktrace::SpanExporter>(new otlp::OtlpExporter(opts));
+  auto exporter  = std::unique_ptr<sdktrace::SpanExporter>(new otlp::OtlpGrpcExporter(opts));
   auto processor = std::unique_ptr<sdktrace::SpanProcessor>(
       new sdktrace::SimpleSpanProcessor(std::move(exporter)));
   auto provider =

examples/otlp/http_main.cc

@@ -0,0 +1,58 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+#include "opentelemetry/exporters/otlp/otlp_http_exporter.h"
+#include "opentelemetry/sdk/trace/simple_processor.h"
+#include "opentelemetry/sdk/trace/tracer_provider.h"
+#include "opentelemetry/trace/provider.h"
+
+#include <string>
+
+#include "foo_library/foo_library.h"
+
+namespace trace    = opentelemetry::trace;
+namespace nostd    = opentelemetry::nostd;
+namespace sdktrace = opentelemetry::sdk::trace;
+namespace otlp     = opentelemetry::exporter::otlp;
+
+namespace
+{
+opentelemetry::exporter::otlp::OtlpHttpExporterOptions opts;
+void InitTracer()
+{
+  // Create OTLP exporter instance
+  auto exporter  = std::unique_ptr<sdktrace::SpanExporter>(new otlp::OtlpHttpExporter(opts));
+  auto processor = std::unique_ptr<sdktrace::SpanProcessor>(
+      new sdktrace::SimpleSpanProcessor(std::move(exporter)));
+  auto provider =
+      nostd::shared_ptr<trace::TracerProvider>(new sdktrace::TracerProvider(std::move(processor)));
+  // Set the global trace provider
+  trace::Provider::SetTracerProvider(provider);
+}
+}  // namespace
+
+int main(int argc, char *argv[])
+{
+  if (argc > 1)
+  {
+    opts.url = argv[1];
+    if (argc > 2)
+    {
+      std::string debug  = argv[2];
+      opts.console_debug = debug != "" && debug != "0" && debug != "no";
+    }
+
+    if (argc > 3)
+    {
+      std::string binary_mode = argv[3];
+      if (binary_mode.size() >= 3 && binary_mode.substr(0, 3) == "bin")
+      {
+        opts.content_type = opentelemetry::exporter::otlp::HttpRequestContentType::kBinary;
+      }
+    }
+  }
+  // Removing this line will leave the default noop TracerProvider in place.
+  InitTracer();
+
+  foo_library();
+}

examples/otlp/opentelemetry-collector-config/config.dev.yaml

@@ -6,6 +6,10 @@ receivers:
     protocols:
       grpc:
         endpoint: 0.0.0.0:4317
+      http:
+        endpoint: "0.0.0.0:55681"
+        cors_allowed_origins:
+        - '*'
 service:
   pipelines:
     traces:

exporters/otlp/BUILD

@@ -35,12 +35,12 @@ cc_library(
 )
 
 cc_library(
-    name = "otlp_exporter",
+    name = "otlp_grpc_exporter",
     srcs = [
-        "src/otlp_exporter.cc",
+        "src/otlp_grpc_exporter.cc",
     ],
     hdrs = [
-        "include/opentelemetry/exporters/otlp/otlp_exporter.h",
+        "include/opentelemetry/exporters/otlp/otlp_grpc_exporter.h",
         "include/opentelemetry/exporters/otlp/protobuf_include_prefix.h",
         "include/opentelemetry/exporters/otlp/protobuf_include_suffix.h",
     ],
@@ -55,6 +55,36 @@ cc_library(
     ],
 )
 
+cc_library(
+    name = "otlp_http_exporter",
+    srcs = [
+        "src/otlp_http_exporter.cc",
+    ],
+    hdrs = [
+        "include/opentelemetry/exporters/otlp/otlp_http_exporter.h",
+        "include/opentelemetry/exporters/otlp/protobuf_include_prefix.h",
+        "include/opentelemetry/exporters/otlp/protobuf_include_suffix.h",
+    ],
+    copts = [
+        "-DCURL_STATICLIB",
+    ],
+    linkopts = select({
+        "//bazel:windows": [
+            "-DEFAULTLIB:advapi32.lib",
+            "-DEFAULTLIB:crypt32.lib",
+        ],
+        "//conditions:default": [],
+    }),
+    strip_include_prefix = "include",
+    deps = [
+        ":otlp_recordable",
+        "//ext/src/http/client/curl:http_client_curl",
+        "//sdk/src/trace",
+        "@com_github_opentelemetry_proto//:trace_service_proto_cc",
+        "@github_nlohmann_json//:json",
+    ],
+)
+
 cc_test(
     name = "otlp_recordable_test",
     srcs = ["test/otlp_recordable_test.cc"],
@@ -65,19 +95,29 @@ cc_test(
 )
 
 cc_test(
-    name = "otlp_exporter_test",
-    srcs = ["test/otlp_exporter_test.cc"],
+    name = "otlp_grpc_exporter_test",
+    srcs = ["test/otlp_grpc_exporter_test.cc"],
+    deps = [
+        ":otlp_grpc_exporter",
+        "//api",
+        "@com_google_googletest//:gtest_main",
+    ],
+)
+
+cc_test(
+    name = "otlp_http_exporter_test",
+    srcs = ["test/otlp_http_exporter_test.cc"],
     deps = [
-        ":otlp_exporter",
+        ":otlp_http_exporter",
         "//api",
         "@com_google_googletest//:gtest_main",
     ],
 )
 
 otel_cc_benchmark(
-    name = "otlp_exporter_benchmark",
-    srcs = ["test/otlp_exporter_benchmark.cc"],
+    name = "otlp_grpc_exporter_benchmark",
+    srcs = ["test/otlp_grpc_exporter_benchmark.cc"],
     deps = [
-        ":otlp_exporter",
+        ":otlp_grpc_exporter",
     ],
 )