[sdk] minor changes in format, linking and var naming

Author: nikhilbhatia08

sdk/include/opentelemetry/sdk/common/container.h

@@ -21,10 +21,10 @@ std::string GetContainerIDFromCgroup(const char *file_path);
 
 /**
   Matches the line with the regex to find container.id
-  @param line contains 
+  @param line a single line of text, typically from the /proc/self/cgroup file
   @return matched id or empty string
 */
-std::string ExtractContainerIDFromLine(std::string &line);
+std::string ExtractContainerIDFromLine(const std::string &line);
 }  // namespace common
 }  // namespace sdk
 OPENTELEMETRY_END_NAMESPACE

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

@@ -40,9 +40,9 @@ class OTELResourceDetector : public ResourceDetector
 };
 
 /**
- * ContainerResourceDetector to detect resource attributes when running inside a containerized environment.
- * This detector extracts metadata such as container ID from cgroup information
- * and sets attributes like container.id following the OpenTelemetry semantic conventions.
+ * ContainerResourceDetector to detect resource attributes when running inside a containerized
+ * environment. This detector extracts metadata such as container ID from cgroup information and
+ * sets attributes like container.id following the OpenTelemetry semantic conventions.
  */
 class ContainerResourceDetector : public ResourceDetector
 {

sdk/src/common/CMakeLists.txt

@@ -1,8 +1,8 @@
 # Copyright The OpenTelemetry Authors
 # SPDX-License-Identifier: Apache-2.0
 
-set(COMMON_SRCS random.cc global_log_handler.cc env_variables.cc container.cc base64.cc
-                disabled.cc)
+set(COMMON_SRCS random.cc global_log_handler.cc env_variables.cc container.cc
+                base64.cc disabled.cc)
 if(WIN32)
   list(APPEND COMMON_SRCS platform/fork_windows.cc)
 else()

sdk/src/common/container.cc

@@ -20,23 +20,23 @@ namespace sdk
 {
 namespace common
 {
-std::string GetContainerIDFromCgroup(const char* file_path) 
+std::string GetContainerIDFromCgroup(const char *file_path)
 {
   std::ifstream cgroup_file(file_path);
   std::string line;
 
-  while(std::getline(cgroup_file, line))
+  while (std::getline(cgroup_file, line))
   {
     std::string container_id = ExtractContainerIDFromLine(line);
-    if(!container_id.empty()) 
+    if (!container_id.empty())
     {
-      return container_id;  
+      return container_id;
     }
   }
   return "";
 }
 
-std::string ExtractContainerIDFromLine(std::string &line)
+std::string ExtractContainerIDFromLine(const std::string &line)
 {
   static const std::regex container_id_regex(R"(^.*/(?:.*[-:])?([0-9a-f]+)(?:\.|\s*$))");
   std::smatch match;

sdk/src/resource/BUILD

@@ -11,5 +11,6 @@ cc_library(
         "//api",
         "//sdk:headers",
         "//sdk/src/common:env_variables",
+        "//sdk/src/common:container",
     ],
 )

sdk/src/resource/CMakeLists.txt

@@ -1,7 +1,7 @@
 # Copyright The OpenTelemetry Authors
 # SPDX-License-Identifier: Apache-2.0
 
-add_library(opentelemetry_resources resource.cc resource_detector.cc)
+add_library(opentelemetry_resources resource.cc resource_detector.cc container_detector.cc)
 
 set_target_properties(opentelemetry_resources PROPERTIES EXPORT_NAME resources)
 set_target_version(opentelemetry_resources)

sdk/src/resource/container_detector.cc

@@ -0,0 +1,39 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+#include "opentelemetry/sdk/common/container.h"
+#include "opentelemetry/sdk/resource/resource.h"
+#include "opentelemetry/sdk/resource/resource_detector.h"
+#include "opentelemetry/semconv/incubating/container_attributes.h"
+#include "opentelemetry/version.h"
+
+#include <string>
+
+OPENTELEMETRY_BEGIN_NAMESPACE
+namespace sdk
+{
+namespace resource
+{
+
+/**
+ * This is the file path from where we can get container.id
+ */
+const char *KCGroupPath = "/proc/self/cgroup";
+
+Resource ContainerResourceDetector::Detect() noexcept
+{
+  std::string container_id = opentelemetry::sdk::common::GetContainerIDFromCgroup(KCGroupPath);
+  if (container_id.empty())
+  {
+    return ResourceDetector::Create({});
+  }
+
+  ResourceAttributes attributes;
+
+  attributes[semconv::container::kContainerId] = container_id;
+  return ResourceDetector::Create(attributes);
+}
+
+}  // namespace resource
+}  // namespace sdk
+OPENTELEMETRY_END_NAMESPACE

sdk/src/resource/resource.cc

@@ -40,10 +40,12 @@ Resource Resource::Merge(const Resource &other) const noexcept
 
 Resource Resource::Create(const ResourceAttributes &attributes, const std::string &schema_url)
 {
-  static auto otel_resource = OTELResourceDetector().Detect();
+  static auto otel_resource      = OTELResourceDetector().Detect();
   static auto container_resource = ContainerResourceDetector().Detect();
-  auto resource =
-      Resource::GetDefault().Merge(otel_resource).Merge(container_resource).Merge(Resource{attributes, schema_url});
+  auto resource                  = Resource::GetDefault()
+                      .Merge(otel_resource)
+                      .Merge(container_resource)
+                      .Merge(Resource{attributes, schema_url});
 
   if (resource.attributes_.find(semconv::service::kServiceName) == resource.attributes_.end())
   {

sdk/src/resource/resource_detector.cc

@@ -3,11 +3,11 @@
 
 #include "opentelemetry/sdk/resource/resource_detector.h"
 #include "opentelemetry/nostd/variant.h"
-#include "opentelemetry/sdk/common/env_variables.h"
 #include "opentelemetry/sdk/common/container.h"
+#include "opentelemetry/sdk/common/env_variables.h"
 #include "opentelemetry/sdk/resource/resource.h"
-#include "opentelemetry/semconv/service_attributes.h"
 #include "opentelemetry/semconv/incubating/container_attributes.h"
+#include "opentelemetry/semconv/service_attributes.h"
 #include "opentelemetry/version.h"
 
 #include <stddef.h>
@@ -21,12 +21,8 @@ namespace sdk
 namespace resource
 {
 
-const char *OTEL_RESOURCE_ATTRIBUTES = "OTEL_RESOURCE_ATTRIBUTES";
-const char *OTEL_SERVICE_NAME        = "OTEL_SERVICE_NAME";
-/**
- * This is the file path from where we can get container.id
-*/
-const char *C_GROUP_PATH = "/proc/self/cgroup";
+const char *KOtelResourceAttributes = "OTEL_RESOURCE_ATTRIBUTES";
+const char *KOtelServiceName        = "OTEL_SERVICE_NAME";
 
 Resource ResourceDetector::Create(const ResourceAttributes &attributes,
                                   const std::string &schema_url)
@@ -39,9 +35,9 @@ Resource OTELResourceDetector::Detect() noexcept
   std::string attributes_str, service_name;
 
   bool attributes_exists = opentelemetry::sdk::common::GetStringEnvironmentVariable(
-      OTEL_RESOURCE_ATTRIBUTES, attributes_str);
+      KOtelResourceAttributes, attributes_str);
   bool service_name_exists =
-      opentelemetry::sdk::common::GetStringEnvironmentVariable(OTEL_SERVICE_NAME, service_name);
+      opentelemetry::sdk::common::GetStringEnvironmentVariable(KOtelServiceName, service_name);
 
   if (!attributes_exists && !service_name_exists)
   {
@@ -74,23 +70,6 @@ Resource OTELResourceDetector::Detect() noexcept
   return ResourceDetector::Create(attributes);
 }
 
-Resource ContainerResourceDetector::Detect() noexcept 
-{
-  std::string container_id = opentelemetry::sdk::common::GetContainerIDFromCgroup(C_GROUP_PATH);
-  if(container_id.empty())
-  {
-    return ResourceDetector::Create({});
-  }
-
-  ResourceAttributes attributes;
-
-  if(!container_id.empty())
-  {
-    attributes[semconv::container::kContainerId] = container_id;
-  }
-  return ResourceDetector::Create(attributes);
-}
-
 }  // namespace resource
 }  // namespace sdk
 OPENTELEMETRY_END_NAMESPACE

sdk/test/resource/resource_test.cc

@@ -4,11 +4,11 @@
 #include <gtest/gtest.h>
 #include <stdint.h>
 #include <cstdlib>
+#include <fstream>
 #include <map>
 #include <string>
 #include <unordered_map>
 #include <utility>
-#include<fstream>
 
 #include "opentelemetry/nostd/variant.h"
 #include "opentelemetry/sdk/common/attribute_utils.h"
@@ -295,9 +295,10 @@ TEST(ResourceTest, DerivedResourceDetector)
   EXPECT_TRUE(received_attributes.find("key") != received_attributes.end());
 }
 
-TEST(ResourceTest, ExctractValidContainerId)
+TEST(ResourceTest, ExtractValidContainerId)
 {
-  std::string line = "13:name=systemd:/podruntime/docker/kubepods/ac679f8a8319c8cf7d38e1adf263bc08d23.aaaa";
+  std::string line =
+      "13:name=systemd:/podruntime/docker/kubepods/ac679f8a8319c8cf7d38e1adf263bc08d23.aaaa";
   std::string extracted_id = opentelemetry::sdk::common::ExtractContainerIDFromLine(line);
   EXPECT_EQ(std::string{"ac679f8a8319c8cf7d38e1adf263bc08d23"}, extracted_id);
 }
@@ -308,20 +309,23 @@ TEST(ResourceTest, ExtractIdFromMockUpCGroupFile)
 
   {
     std::ofstream outfile(filename);
-    outfile << "13:name=systemd:/kuberuntime/containerd/kubepods-pod872d2066_00ef_48ea_a7d8_51b18b72d739:cri-containerd:e857a4bf05a69080a759574949d7a0e69572e27647800fa7faff6a05a8332aa1\n";
+    outfile << "13:name=systemd:/kuberuntime/containerd"
+               "/kubepods-pod872d2066_00ef_48ea_a7d8_51b18b72d739:cri-containerd:"
+               "e857a4bf05a69080a759574949d7a0e69572e27647800fa7faff6a05a8332aa1\n";
     outfile << "9:cpu:/not-a-container\n";
   }
 
   std::string container_id = opentelemetry::sdk::common::GetContainerIDFromCgroup(filename);
-  EXPECT_EQ(container_id, std::string{"e857a4bf05a69080a759574949d7a0e69572e27647800fa7faff6a05a8332aa1"});
+  EXPECT_EQ(container_id,
+            std::string{"e857a4bf05a69080a759574949d7a0e69572e27647800fa7faff6a05a8332aa1"});
 
   std::remove(filename);
 }
 
 TEST(ResourceTest, DoesNotExtractInvalidLine)
 {
   std::string line = "this line does not contain a container id";
-  std::string id = opentelemetry::sdk::common::ExtractContainerIDFromLine(line);
+  std::string id   = opentelemetry::sdk::common::ExtractContainerIDFromLine(line);
   EXPECT_EQ(id, std::string{""});
 }