[SDK] Support for OTEL_SERVICE_NAME (#2577)

sdk/src/resource/resource_detector.cc

@@ -4,6 +4,7 @@
 #include "opentelemetry/sdk/resource/resource_detector.h"
 #include "opentelemetry/sdk/common/env_variables.h"
 #include "opentelemetry/sdk/resource/resource.h"
+#include "opentelemetry/sdk/resource/semantic_conventions.h"
 
 #include <sstream>
 #include <string>
@@ -15,28 +16,45 @@ namespace resource
 {
 
 const char *OTEL_RESOURCE_ATTRIBUTES = "OTEL_RESOURCE_ATTRIBUTES";
+const char *OTEL_SERVICE_NAME = "OTEL_SERVICE_NAME";
 
 Resource OTELResourceDetector::Detect() noexcept
 {
- std::string attributes_str;
- bool exists;
+ std::string attributes_str, service_name;
 
- exists = opentelemetry::sdk::common::GetStringEnvironmentVariable(OTEL_RESOURCE_ATTRIBUTES,
- attributes_str);
- if (!exists)
+ bool attributes_exists = opentelemetry::sdk::common::GetStringEnvironmentVariable(
+ OTEL_RESOURCE_ATTRIBUTES, attributes_str);
+ bool service_name_exists =
+ opentelemetry::sdk::common::GetStringEnvironmentVariable(OTEL_SERVICE_NAME, service_name);
+
+ if (!attributes_exists && !service_name_exists)
  {
  return Resource();
  }
+
  ResourceAttributes attributes;
- std::istringstream iss(attributes_str);
- std::string token;
- while (std::getline(iss, token, ','))
+
+ if (attributes_exists)
  {
- size_t pos = token.find('=');
- std::string key = token.substr(0, pos);
- std::string value = token.substr(pos + 1);
- attributes[key] = value;
+ std::istringstream iss(attributes_str);
+ std::string token;
+ while (std::getline(iss, token, ','))
+ {
+ size_t pos = token.find('=');
+ if (pos != std::string::npos)
+ {
+ std::string key = token.substr(0, pos);
+ std::string value = token.substr(pos + 1);
+ attributes[key] = value;
+ }
+ }
  }
+
+ if (service_name_exists)
+ {
+ attributes[SemanticConventions::kServiceName] = service_name;
+ }
+
  return Resource(attributes);
 }
 

sdk/test/resource/resource_test.cc

@@ -220,6 +220,30 @@ TEST(ResourceTest, OtelResourceDetector)
  unsetenv("OTEL_RESOURCE_ATTRIBUTES");
 }
 
+TEST(ResourceTest, OtelResourceDetectorServiceNameOverride)
+{
+ std::map<std::string, std::string> expected_attributes = {{"service.name", "new_name"}};
+
+ setenv("OTEL_RESOURCE_ATTRIBUTES", "service.name=old_name", 1);
+ setenv("OTEL_SERVICE_NAME", "new_name", 1);
+
+ OTELResourceDetector detector;
+ auto resource = detector.Detect();
+ auto received_attributes = resource.GetAttributes();
+ for (auto &e : received_attributes)
+ {
+ EXPECT_TRUE(expected_attributes.find(e.first) != expected_attributes.end());
+ if (expected_attributes.find(e.first) != expected_attributes.end())
+ {
+ EXPECT_EQ(expected_attributes.find(e.first)->second, nostd::get<std::string>(e.second));
+ }
+ }
+ EXPECT_EQ(received_attributes.size(), expected_attributes.size());
+
+ unsetenv("OTEL_SERVICE_NAME");
+ unsetenv("OTEL_RESOURCE_ATTRIBUTES");
+}
+
 TEST(ResourceTest, OtelResourceDetectorEmptyEnv)
 {
  std::map<std::string, std::string> expected_attributes = {};