[BUG] Check what curl_global_init returns (#4434)

Ensure HttpCurlGlobalInitializer checks the return value of
  curl_global_init. If initialization fails, log an error, avoid calling curl_global_cleanup, and cause HttpClient and HttpClientSync to report
  SessionState::CreateFailed.

    Fixes #4434

Signed-off-by: Varun <v08pandey@gmail.com>

Author: Dyfintie

ext/include/opentelemetry/ext/http/client/curl/http_client_curl.h

@@ -51,10 +51,24 @@ class HttpCurlGlobalInitializer
 
   HttpCurlGlobalInitializer();
 
+  friend class HttpClientTestPeer;
+
+  // Test constructor to simulate init failure without calling curl_global_init
+  HttpCurlGlobalInitializer(CURLcode code, bool is_initialized)
+      : init_code_{code}, is_initialized_{is_initialized}
+  {}
+
+  CURLcode init_code_{CURLE_OK};
+  bool is_initialized_{false};
+
 public:
   ~HttpCurlGlobalInitializer();
 
   static nostd::shared_ptr<HttpCurlGlobalInitializer> GetInstance();
+
+  // added accessors here
+  bool IsValid() const noexcept { return is_initialized_; }
+  CURLcode GetStatus() const noexcept { return init_code_; }
 };
 
 class Request : public opentelemetry::ext::http::client::Request
@@ -253,6 +267,11 @@ class HttpClientSync : public opentelemetry::ext::http::client::HttpClientSync
       const opentelemetry::ext::http::client::Headers &headers,
       const opentelemetry::ext::http::client::Compression &compression) noexcept override
   {
+    if (!curl_global_initializer_ || !curl_global_initializer_->IsValid())
+    {
+      return opentelemetry::ext::http::client::Result(
+          nullptr, opentelemetry::ext::http::client::SessionState::CreateFailed);
+    }
     opentelemetry::ext::http::client::Body body;
 
     HttpOperation curl_operation(opentelemetry::ext::http::client::Method::Get, url.data(),
@@ -283,6 +302,11 @@ class HttpClientSync : public opentelemetry::ext::http::client::HttpClientSync
       const opentelemetry::ext::http::client::Headers &headers,
       const opentelemetry::ext::http::client::Compression &compression) noexcept override
   {
+    if (!curl_global_initializer_ || !curl_global_initializer_->IsValid())
+    {
+      return opentelemetry::ext::http::client::Result(
+          nullptr, opentelemetry::ext::http::client::SessionState::CreateFailed);
+    }
     HttpOperation curl_operation(opentelemetry::ext::http::client::Method::Post, url.data(),
                                  ssl_options, nullptr, headers, body, compression);
     curl_operation.SendSync();
@@ -308,6 +332,7 @@ class HttpClientSync : public opentelemetry::ext::http::client::HttpClientSync
   ~HttpClientSync() override {}
 
 private:
+  friend class HttpClientTestPeer;
   nostd::shared_ptr<HttpCurlGlobalInitializer> curl_global_initializer_;
 };
 
@@ -325,6 +350,12 @@ class HttpClient : public opentelemetry::ext::http::client::HttpClient
 
   ~HttpClient() override;
 
+  inline bool IsValid() const noexcept
+  {
+    return curl_global_initializer_ && curl_global_initializer_->IsValid() &&
+           multi_handle_ != nullptr;
+  }
+
   std::shared_ptr<opentelemetry::ext::http::client::Session> CreateSession(
       nostd::string_view url) noexcept override;
 
@@ -366,6 +397,7 @@ class HttpClient : public opentelemetry::ext::http::client::HttpClient
   bool doRetrySessions(bool report_all);
   void resetMultiHandle();
 
+  nostd::shared_ptr<HttpCurlGlobalInitializer> curl_global_initializer_;
   std::mutex multi_handle_m_;
   CURLM *multi_handle_;
   std::atomic<uint64_t> next_session_id_{0};
@@ -387,8 +419,6 @@ class HttpClient : public opentelemetry::ext::http::client::HttpClient
 
   std::chrono::milliseconds background_thread_wait_for_;
   std::atomic<bool> is_shutdown_{false};
-
-  nostd::shared_ptr<HttpCurlGlobalInitializer> curl_global_initializer_;
 };
 
 }  // namespace curl

ext/src/http/client/curl/http_client_curl.cc

@@ -48,13 +48,21 @@ namespace curl
 {
 
 HttpCurlGlobalInitializer::HttpCurlGlobalInitializer()
+    : init_code_(curl_global_init(CURL_GLOBAL_ALL)), is_initialized_(init_code_ == CURLE_OK)
 {
-  curl_global_init(CURL_GLOBAL_ALL);
+  if (!is_initialized_)
+  {
+    OTEL_INTERNAL_LOG_ERROR("[HTTP Client Curl] curl_global_init failed with error code: "
+                            << static_cast<int>(init_code_));
+  }
 }
 
 HttpCurlGlobalInitializer::~HttpCurlGlobalInitializer()
 {
-  curl_global_cleanup();
+  if (is_initialized_)
+  {
+    curl_global_cleanup();
+  }
 }
 
 nostd::shared_ptr<HttpCurlGlobalInitializer> HttpCurlGlobalInitializer::GetInstance()
@@ -141,6 +149,18 @@ static int deflateInPlace(z_stream *strm, unsigned char *buf, uint32_t len, uint
 void Session::SendRequest(
     std::shared_ptr<opentelemetry::ext::http::client::EventHandler> callback) noexcept
 {
+  // Returning early before MaybeSpawnBackgroundThread() ensures the background IO
+  // loop never starts with an uninitialized or null multi_handle_.
+  if (!http_client_.IsValid())
+  {
+    if (callback)
+    {
+      callback->OnEvent(opentelemetry::ext::http::client::SessionState::CreateFailed,
+                        "curl initialization failed");
+    }
+    is_session_active_.store(false, std::memory_order_release);
+    return;
+  }
   is_session_active_.store(true, std::memory_order_release);
   const auto &url       = host_ + http_request_->uri_;
   auto callback_ptr     = callback.get();
@@ -271,24 +291,28 @@ void Session::FinishOperation()
 }
 
 HttpClient::HttpClient()
-    : multi_handle_(curl_multi_init()),
+    : curl_global_initializer_(HttpCurlGlobalInitializer::GetInstance()),
+      multi_handle_(curl_global_initializer_ && curl_global_initializer_->IsValid()
+                        ? curl_multi_init()
+                        : nullptr),
       next_session_id_{0},
       max_sessions_per_connection_{8},
       background_thread_instrumentation_(nullptr),
       scheduled_delay_milliseconds_{std::chrono::milliseconds(256)},
-      background_thread_wait_for_{std::chrono::minutes{1}},
-      curl_global_initializer_(HttpCurlGlobalInitializer::GetInstance())
+      background_thread_wait_for_{std::chrono::minutes{1}}
 {}
 
 HttpClient::HttpClient(
     const std::shared_ptr<sdk::common::ThreadInstrumentation> &thread_instrumentation)
-    : multi_handle_(curl_multi_init()),
+    : curl_global_initializer_(HttpCurlGlobalInitializer::GetInstance()),
+      multi_handle_(curl_global_initializer_ && curl_global_initializer_->IsValid()
+                        ? curl_multi_init()
+                        : nullptr),
       next_session_id_{0},
       max_sessions_per_connection_{8},
       background_thread_instrumentation_(thread_instrumentation),
       scheduled_delay_milliseconds_{std::chrono::milliseconds(256)},
-      background_thread_wait_for_{std::chrono::minutes{1}},
-      curl_global_initializer_(HttpCurlGlobalInitializer::GetInstance())
+      background_thread_wait_for_{std::chrono::minutes{1}}
 {}
 
 HttpClient::~HttpClient()
@@ -317,7 +341,11 @@ HttpClient::~HttpClient()
   }
   {
     std::lock_guard<std::mutex> lock_guard{multi_handle_m_};
-    curl_multi_cleanup(multi_handle_);
+    if (multi_handle_)
+    {
+      curl_multi_cleanup(multi_handle_);
+      multi_handle_ = nullptr;
+    }
   }
 }
 

ext/test/http/curl_http_test.cc

@@ -1,11 +1,11 @@
 // Copyright The OpenTelemetry Authors
 // SPDX-License-Identifier: Apache-2.0
 
+#include <curl/curl.h>
 #include <curl/curlver.h>
 #include "gtest/gtest.h"
 
 #ifdef ENABLE_OTLP_RETRY_PREVIEW
-#  include <curl/curl.h>
 #  include "gmock/gmock.h"
 #endif  // ENABLE_OTLP_RETRY_PREVIEW
 
@@ -56,6 +56,35 @@ class HttpClientTestPeer
 {
 public:
   static void ResetMultiHandle(HttpClient &client) { client.resetMultiHandle(); }
+  // mock initializer
+  static nostd::shared_ptr<HttpCurlGlobalInitializer> CreateMockInitializer(CURLcode code,
+                                                                            bool is_valid)
+  {
+    return nostd::shared_ptr<HttpCurlGlobalInitializer>(
+        new HttpCurlGlobalInitializer(code, is_valid));
+  }
+  // injects the mock initializer into an HttpClient
+  static void SetInitializer(HttpClient &client,
+                             const nostd::shared_ptr<HttpCurlGlobalInitializer> &initializer)
+  {
+    client.curl_global_initializer_ = initializer;
+    if (!initializer || !initializer->IsValid())
+    {
+      std::lock_guard<std::mutex> lk(client.multi_handle_m_);
+      if (client.multi_handle_)
+      {
+        curl_multi_cleanup(client.multi_handle_);
+        client.multi_handle_ = nullptr;
+      }
+    }
+  }
+
+  // injects the mock initializer into an HttpClientSync
+  static void SetSyncInitializer(HttpClientSync &client,
+                                 const nostd::shared_ptr<HttpCurlGlobalInitializer> &initializer)
+  {
+    client.curl_global_initializer_ = initializer;
+  }
 };
 }  // namespace curl
 }  // namespace client
@@ -77,6 +106,10 @@ class CustomEventHandler : public http_client::EventHandler
   {
     switch (state)
     {
+      // CreateFailed occurs when initialization or request preparation fails before
+      // network dispatch (e.g., if curl_global_init failed or session setup failed).
+      // Marking is_called_ ensures tests expecting early failure notifications register it.
+      case http_client::SessionState::CreateFailed:
       case http_client::SessionState::ConnectFailed:
       case http_client::SessionState::SendFailed: {
         is_called_.store(true, std::memory_order_release);
@@ -1095,6 +1128,52 @@ TEST_F(BasicCurlHttpTests, GzipIncompressibleData)
   session_manager->CancelAllSessions();
   session_manager->FinishAllSessions();
 }
+
 #endif  // ENABLE_OTLP_COMPRESSION_PREVIEW
+// 2 new tests
+TEST_F(BasicCurlHttpTests, GlobalInitFailureHttpClient)
+{
+  curl::HttpClient client;
+  auto mock_init =
+      http_client::curl::HttpClientTestPeer::CreateMockInitializer(CURLE_FAILED_INIT, false);
+  http_client::curl::HttpClientTestPeer::SetInitializer(client, mock_init);
+
+  EXPECT_FALSE(client.IsValid());
+
+  auto session = client.CreateSession("http://127.0.0.1:19000/get/");
+  auto request = session->CreateRequest();
+  request->SetMethod(http_client::Method::Get);
+  request->SetUri("get/");
+
+  auto handler = std::make_shared<CustomEventHandler>();
+  session->SendRequest(handler);
+
+  EXPECT_FALSE(session->IsSessionActive());
+  EXPECT_TRUE(handler->is_called_.load(std::memory_order_acquire));
+  EXPECT_FALSE(handler->got_response_.load(std::memory_order_acquire));
+
+  EXPECT_TRUE(client.CancelAllSessions());
+  EXPECT_TRUE(client.FinishAllSessions());
+}
+
+TEST_F(BasicCurlHttpTests, GlobalInitFailureHttpClientSync)
+{
+  curl::HttpClientSync sync_client;
+  auto mock_init =
+      http_client::curl::HttpClientTestPeer::CreateMockInitializer(CURLE_FAILED_INIT, false);
+  http_client::curl::HttpClientTestPeer::SetSyncInitializer(sync_client, mock_init);
+
+  http_client::HttpSslOptions ssl_opts;
+  auto get_result =
+      sync_client.Get("http://127.0.0.1:19000/get/", ssl_opts, {}, http_client::Compression::kNone);
+  EXPECT_FALSE(get_result);
+  EXPECT_EQ(get_result.GetSessionState(), http_client::SessionState::CreateFailed);
+
+  http_client::Body body;
+  auto post_result = sync_client.Post("http://127.0.0.1:19000/post/", ssl_opts, body, {},
+                                      http_client::Compression::kNone);
+  EXPECT_FALSE(post_result);
+  EXPECT_EQ(post_result.GetSessionState(), http_client::SessionState::CreateFailed);
+}
 
 }  // namespace