Refresh code from PR #2518, to fix review comments.

Author: marcalff

sdk/include/opentelemetry/sdk/configuration/invalid_schema_exception.h

@@ -20,11 +20,6 @@ class InvalidSchemaException : public std::runtime_error
 {
 public:
   InvalidSchemaException(const std::string &msg) : std::runtime_error(msg) {}
-  InvalidSchemaException(InvalidSchemaException &&)                      = default;
-  InvalidSchemaException(const InvalidSchemaException &)                 = default;
-  InvalidSchemaException &operator=(InvalidSchemaException &&)           = default;
-  InvalidSchemaException &operator=(const InvalidSchemaException &other) = default;
-  ~InvalidSchemaException() override                                     = default;
 };
 
 }  // namespace configuration

sdk/src/configuration/document_node.cc

@@ -6,6 +6,7 @@
 #include <ostream>
 #include <string>
 
+#include "opentelemetry/sdk/common/env_variables.h"
 #include "opentelemetry/sdk/common/global_log_handler.h"
 #include "opentelemetry/sdk/configuration/document_node.h"
 #include "opentelemetry/sdk/configuration/invalid_schema_exception.h"
@@ -106,7 +107,8 @@ std::string DocumentNode::DoOneSubstitution(const std::string &text)
   std::string::size_type pos;
   std::string name;
   std::string fallback;
-  const char *sub;
+  std::string sub;
+  bool env_exists;
 
   if (len < 4)
   {
@@ -196,8 +198,8 @@ std::string DocumentNode::DoOneSubstitution(const std::string &text)
     end_fallback   = len - 1;
   }
 
-  sub = std::getenv(name.c_str());
-  if (sub != nullptr)
+  env_exists = sdk::common::GetStringEnvironmentVariable(name.c_str(), sub);
+  if (env_exists)
   {
     return sub;
   }

sdk/src/configuration/yaml_configuration_parser.cc

@@ -1,14 +1,14 @@
 // Copyright The OpenTelemetry Authors
 // SPDX-License-Identifier: Apache-2.0
 
-#include <cstdlib>
 #include <exception>
 #include <fstream>
 #include <memory>
 #include <sstream>
 #include <string>
 #include <utility>
 
+#include "opentelemetry/sdk/common/env_variables.h"
 #include "opentelemetry/sdk/common/global_log_handler.h"
 #include "opentelemetry/sdk/configuration/configuration.h"
 #include "opentelemetry/sdk/configuration/configuration_parser.h"
@@ -29,8 +29,12 @@ std::unique_ptr<Configuration> YamlConfigurationParser::ParseFile(const std::str
 
   if (input_file.empty())
   {
-    const char *env_var = std::getenv("OTEL_EXPERIMENTAL_CONFIG_FILE");
-    if (env_var != nullptr)
+    static std::string env_var_name("OTEL_EXPERIMENTAL_CONFIG_FILE");
+    std::string env_var;
+    bool env_exists;
+    env_exists = sdk::common::GetStringEnvironmentVariable(env_var_name.c_str(), env_var);
+
+    if (env_exists)
     {
       input_file = env_var;
     }