Resource sdk Implementation (#502)

examples/multithreaded/main.cc

@@ -1,3 +1,4 @@
+#include "opentelemetry/sdk/resource/resource.h"
 #include "opentelemetry/sdk/trace/simple_processor.h"
 #include "opentelemetry/sdk/trace/tracer_provider.h"
 #include "opentelemetry/trace/provider.h"
@@ -18,7 +19,7 @@ void initTracer()
   auto processor = std::shared_ptr<sdktrace::SpanProcessor>(
       new sdktrace::SimpleSpanProcessor(std::move(exporter)));
   auto provider = nostd::shared_ptr<opentelemetry::trace::TracerProvider>(
-      new sdktrace::TracerProvider(processor));
+      new sdktrace::TracerProvider(processor, opentelemetry::sdk::resource::Resource::Create({})));
   // Set the global trace provider
   opentelemetry::trace::Provider::SetTracerProvider(provider);
 }

examples/simple/main.cc

@@ -15,7 +15,9 @@ void initTracer()
   auto processor = std::shared_ptr<sdktrace::SpanProcessor>(
       new sdktrace::SimpleSpanProcessor(std::move(exporter)));
   auto provider = nostd::shared_ptr<opentelemetry::trace::TracerProvider>(
-      new sdktrace::TracerProvider(processor));
+      new sdktrace::TracerProvider(processor, opentelemetry::sdk::resource::Resource::Create({}),
+                                   std::make_shared<opentelemetry::sdk::trace::AlwaysOnSampler>()));
+
   // Set the global trace provider
   opentelemetry::trace::Provider::SetTracerProvider(provider);
 }

ext/test/zpages/tracez_data_aggregator_test.cc

@@ -3,6 +3,7 @@
 #include <gtest/gtest.h>
 
 #include "opentelemetry/ext/zpages/tracez_processor.h"
+#include "opentelemetry/sdk/resource/resource.h"
 #include "opentelemetry/sdk/trace/recordable.h"
 #include "opentelemetry/sdk/trace/tracer.h"
 
@@ -34,7 +35,8 @@ class TracezDataAggregatorTest : public ::testing::Test
   void SetUp() override
   {
     std::shared_ptr<TracezSpanProcessor> processor(new TracezSpanProcessor());
-    tracer                 = std::shared_ptr<opentelemetry::trace::Tracer>(new Tracer(processor));
+    auto resource = opentelemetry::sdk::resource::Resource::Create({});
+    tracer        = std::shared_ptr<opentelemetry::trace::Tracer>(new Tracer(processor, resource));
     tracez_data_aggregator = std::unique_ptr<TracezDataAggregator>(
         new TracezDataAggregator(processor, milliseconds(10)));
   }

ext/test/zpages/tracez_processor_test.cc

@@ -6,6 +6,7 @@
 
 #include "opentelemetry/ext/zpages/threadsafe_span_data.h"
 #include "opentelemetry/nostd/span.h"
+#include "opentelemetry/sdk/resource/resource.h"
 #include "opentelemetry/sdk/trace/tracer.h"
 
 using namespace opentelemetry::sdk::trace;
@@ -174,8 +175,10 @@ class TracezProcessor : public ::testing::Test
 protected:
   void SetUp() override
   {
-    processor  = std::shared_ptr<TracezSpanProcessor>(new TracezSpanProcessor());
-    tracer     = std::shared_ptr<opentelemetry::trace::Tracer>(new Tracer(processor));
+    processor     = std::shared_ptr<TracezSpanProcessor>(new TracezSpanProcessor());
+    auto resource = opentelemetry::sdk::resource::Resource::Create({});
+
+    tracer     = std::shared_ptr<opentelemetry::trace::Tracer>(new Tracer(processor, resource));
     auto spans = processor->GetSpanSnapshot();
     running    = spans.running;
     completed  = std::move(spans.completed);

sdk/include/opentelemetry/sdk/resource/resource.h

@@ -0,0 +1,77 @@
+#pragma once
+
+#include "opentelemetry/sdk/common/attribute_utils.h"
+#include "opentelemetry/sdk/resource/resource_detector.h"
+#include "opentelemetry/sdk/version/version.h"
+#include "opentelemetry/version.h"
+
+#include <memory>
+#include <sstream>
+#include <unordered_map>
+
+OPENTELEMETRY_BEGIN_NAMESPACE
+namespace sdk
+{
+namespace resource
+{
+
+using ResourceAttributes =
+    std::unordered_map<std::string, opentelemetry::sdk::common::OwnedAttributeValue>;
+
+class Resource
+{
+public:
+  Resource(const Resource &) = default;
+
+  const ResourceAttributes &GetAttributes() const noexcept;
+
+  /**
+   * Returns a new, merged {@link Resource} by merging the current Resource
+   * with the other Resource. In case of a collision, current Resource takes
+   * precedence.
+   *
+   * @param other the Resource that will be merged with this.
+   * @returns the newly merged Resource.
+   */
+
+  Resource Merge(const Resource &other) noexcept;
+
+  /**
+   * Returns a newly created Resource with the specified attributes.
+   * It adds (merge) SDK attributes and OTEL attributes before returning.
+   * @param attributes for this resource
+   * @returns the newly created Resource.
+   */
+
+  static Resource Create(const ResourceAttributes &attributes);
+
+  /**
+   * Returns an Empty resource.
+   */
+
+  static Resource &GetEmpty();
+
+  /**
+   * Returns a Resource that indentifies the SDK in use.
+   */
+
+  static Resource &GetDefault();
+
+protected:
+  /**
+   * The constructor is protected and only for use internally by the class and
+   * inside ResourceDetector class.
+   * Users should use the Create factory method to obtain a Resource
+   * instance.
+   */
+  Resource(const ResourceAttributes &attributes = ResourceAttributes()) noexcept;
+
+private:
+  ResourceAttributes attributes_;
+
+  friend class OTELResourceDetector;
+};
+
+}  // namespace resource
+}  // namespace sdk
+OPENTELEMETRY_END_NAMESPACE

sdk/include/opentelemetry/sdk/resource/resource_detector.h

@@ -0,0 +1,35 @@
+#pragma once
+
+#include "opentelemetry/nostd/unique_ptr.h"
+#include "opentelemetry/version.h"
+
+OPENTELEMETRY_BEGIN_NAMESPACE
+namespace sdk
+{
+namespace resource
+{
+
+class Resource;
+
+/**
+ * Interface for a Resource Detector
+ */
+class ResourceDetector
+{
+public:
+  virtual Resource Detect() = 0;
+};
+
+/**
+ * OTelResourceDetector to detect the presence of and create a Resource
+ * from the OTEL_RESOURCE_ATTRIBUTES environment variable.
+ */
+class OTELResourceDetector : public ResourceDetector
+{
+public:
+  Resource Detect() noexcept override;
+};
+
+}  // namespace resource
+}  // namespace sdk
+OPENTELEMETRY_END_NAMESPACE

sdk/include/opentelemetry/sdk/trace/tracer.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include "opentelemetry/sdk/common/atomic_shared_ptr.h"
+#include "opentelemetry/sdk/resource/resource.h"
 #include "opentelemetry/sdk/trace/processor.h"
 #include "opentelemetry/sdk/trace/samplers/always_on.h"
 #include "opentelemetry/trace/noop.h"
@@ -23,6 +24,7 @@ class Tracer final : public trace_api::Tracer, public std::enable_shared_from_th
    * nullptr.
    */
   explicit Tracer(std::shared_ptr<SpanProcessor> processor,
+                  const opentelemetry::sdk::resource::Resource &resource,
                   std::shared_ptr<Sampler> sampler = std::make_shared<AlwaysOnSampler>()) noexcept;
 
   /**
@@ -57,6 +59,7 @@ class Tracer final : public trace_api::Tracer, public std::enable_shared_from_th
 private:
   opentelemetry::sdk::AtomicSharedPtr<SpanProcessor> processor_;
   const std::shared_ptr<Sampler> sampler_;
+  const opentelemetry::sdk::resource::Resource &resource_;
 };
 }  // namespace trace
 }  // namespace sdk

sdk/include/opentelemetry/sdk/trace/tracer_provider.h

@@ -5,6 +5,7 @@
 #include <string>
 
 #include "opentelemetry/nostd/shared_ptr.h"
+#include "opentelemetry/sdk/resource/resource.h"
 #include "opentelemetry/sdk/trace/processor.h"
 #include "opentelemetry/sdk/trace/samplers/always_on.h"
 #include "opentelemetry/sdk/trace/tracer.h"
@@ -27,6 +28,8 @@ class TracerProvider final : public opentelemetry::trace::TracerProvider
    */
   explicit TracerProvider(
       std::shared_ptr<SpanProcessor> processor,
+      opentelemetry::sdk::resource::Resource &&resource =
+          opentelemetry::sdk::resource::Resource::Create({}),
       std::shared_ptr<Sampler> sampler = std::make_shared<AlwaysOnSampler>()) noexcept;
 
   opentelemetry::nostd::shared_ptr<opentelemetry::trace::Tracer> GetTracer(
@@ -48,10 +51,16 @@ class TracerProvider final : public opentelemetry::trace::TracerProvider
 
   /**
    * Obtain the sampler associated with this tracer provider.
-   * @return The span processor for this tracer provider.
+   * @return The sampler for this tracer provider.
    */
   std::shared_ptr<Sampler> GetSampler() const noexcept;
 
+  /**
+   * Obtain the resource associated with this tracer provider.
+   * @return The resource for this tracer provider.
+   */
+  const opentelemetry::sdk::resource::Resource &GetResource() const noexcept;
+
   /**
    * Shutdown the span processor associated with this tracer provider.
    */
@@ -61,6 +70,7 @@ class TracerProvider final : public opentelemetry::trace::TracerProvider
   opentelemetry::sdk::AtomicSharedPtr<SpanProcessor> processor_;
   std::shared_ptr<opentelemetry::trace::Tracer> tracer_;
   const std::shared_ptr<Sampler> sampler_;
+  const opentelemetry::sdk::resource::Resource resource_;
 };
 }  // namespace trace
 }  // namespace sdk

sdk/src/CMakeLists.txt

@@ -3,3 +3,4 @@ add_subdirectory(trace)
 add_subdirectory(metrics)
 add_subdirectory(logs)
 add_subdirectory(version)
+add_subdirectory(resource)

sdk/src/resource/BUILD

@@ -0,0 +1,26 @@
+# Copyright 2020, OpenTelemetry Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+package(default_visibility = ["//visibility:public"])
+
+cc_library(
+    name = "resource",
+    srcs = glob(["**/*.cc"]),
+    hdrs = glob(["**/*.h"]),
+    include_prefix = "src/resource",
+    deps = [
+        "//api",
+        "//sdk:headers",
+    ],
+)

sdk/src/resource/CMakeLists.txt

@@ -0,0 +1,16 @@
+add_library(opentelemetry_resources resource.cc resource_detector.cc)
+
+set_target_properties(opentelemetry_resources PROPERTIES EXPORT_NAME resources)
+
+target_link_libraries(opentelemetry_resources opentelemetry_common)
+
+target_include_directories(
+  opentelemetry_resources
+  PUBLIC "$<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/sdk/include>")
+
+install(
+  TARGETS opentelemetry_resources
+  EXPORT "${PROJECT_NAME}-target"
+  RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+  LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+  ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR})

sdk/src/resource/resource.cc

@@ -0,0 +1,60 @@
+#include "opentelemetry/sdk/resource/resource.h"
+#include "opentelemetry/nostd/span.h"
+#include "opentelemetry/sdk/resource/resource_detector.h"
+#include "opentelemetry/version.h"
+
+OPENTELEMETRY_BEGIN_NAMESPACE
+namespace sdk
+{
+namespace resource
+{
+
+const std::string kTelemetrySdkLanguage = "telemetry.sdk.language";
+const std::string kTelemetrySdkName     = "telemetry.sdk.name";
+const std::string kTelemetrySdkVersion  = "telemetry.sdk.version";
+
+Resource::Resource(const ResourceAttributes &attributes) noexcept : attributes_(attributes) {}
+
+Resource Resource::Merge(const Resource &other) noexcept
+{
+  ResourceAttributes merged_resource_attributes(other.attributes_);
+  merged_resource_attributes.insert(attributes_.begin(), attributes_.end());
+  return Resource(merged_resource_attributes);
+}
+
+Resource Resource::Create(const ResourceAttributes &attributes)
+{
+  static auto otel_resource = OTELResourceDetector().Detect();
+  auto default_resource     = Resource::GetDefault();
+
+  if (attributes.size() > 0)
+  {
+    Resource tmp_resource(attributes);
+    auto merged_resource = tmp_resource.Merge(default_resource);
+    return merged_resource.Merge(otel_resource);
+  }
+  return default_resource.Merge(otel_resource);
+}
+
+Resource &Resource::GetEmpty()
+{
+  static Resource empty_resource;
+  return empty_resource;
+}
+
+Resource &Resource::GetDefault()
+{
+  static Resource default_resource({{kTelemetrySdkLanguage, "cpp"},
+                                    {kTelemetrySdkName, "opentelemetry"},
+                                    {kTelemetrySdkVersion, OPENTELEMETRY_SDK_VERSION}});
+  return default_resource;
+}
+
+const ResourceAttributes &Resource::GetAttributes() const noexcept
+{
+  return attributes_;
+}
+
+}  // namespace resource
+}  // namespace sdk
+OPENTELEMETRY_END_NAMESPACE

sdk/src/resource/resource_detector.cc

@@ -0,0 +1,34 @@
+#include "opentelemetry/sdk/resource/resource_detector.h"
+#include <cstdlib>
+#include "opentelemetry/sdk/resource/resource.h"
+
+OPENTELEMETRY_BEGIN_NAMESPACE
+namespace sdk
+{
+namespace resource
+{
+
+const char *OTEL_RESOURCE_ATTRIBUTES = "OTEL_RESOURCE_ATTRIBUTES";
+
+Resource OTELResourceDetector::Detect() noexcept
+{
+  char *attributes_str = std::getenv(OTEL_RESOURCE_ATTRIBUTES);
+  if (attributes_str == nullptr)
+    return Resource();
+  // return Resource::GetEmpty();
+  ResourceAttributes attributes;
+  std::istringstream iss(attributes_str);
+  std::string token;
+  while (std::getline(iss, token, ','))
+  {
+    size_t pos        = token.find('=');
+    std::string key   = token.substr(0, pos);
+    std::string value = token.substr(pos + 1);
+    attributes[key]   = value;
+  }
+  return Resource(attributes);
+}
+
+}  // namespace resource
+}  // namespace sdk
+OPENTELEMETRY_END_NAMESPACE

sdk/src/trace/BUILD

@@ -23,5 +23,6 @@ cc_library(
         "//api",
         "//sdk:headers",
         "//sdk/src/common:random",
+        "//sdk/src/resource",
     ],
 )