test(otlp): add local HTTP export integration test

tests/otlp_http_logger_integration_test.cpp

@@ -0,0 +1,123 @@
+#include <logit.hpp>
+
+#ifdef LOGIT_WITH_OTLP
+
+#include <server_http.hpp>
+
+#include <cassert>
+#include <chrono>
+#include <condition_variable>
+#include <mutex>
+#include <string>
+#include <thread>
+
+using HttpServer = SimpleWeb::Server<SimpleWeb::HTTP>;
+
+namespace {
+
+struct CapturedRequest {
+    std::mutex mutex;
+    std::condition_variable cv;
+    bool received = false;
+    std::string body;
+};
+
+bool wait_for_server(unsigned short port) {
+    for (int i = 0; i < 50; ++i) {
+        try {
+            kurlyk::HttpClient client("http://127.0.0.1:" + std::to_string(port));
+            client.set_timeout(1);
+            auto future = client.get("/health", {}, {});
+            if (future.wait_for(std::chrono::seconds(2)) == std::future_status::ready) {
+                auto response = future.get();
+                if (response && response->status_code == 200) {
+                    return true;
+                }
+            }
+        } catch (...) {
+        }
+        std::this_thread::sleep_for(std::chrono::milliseconds(50));
+    }
+    return false;
+}
+
+} // namespace
+
+int main() {
+    const unsigned short port = 43180;
+
+    CapturedRequest captured;
+    HttpServer server;
+    server.config.port = port;
+
+    server.resource["^/health$"]["GET"] = [](std::shared_ptr<HttpServer::Response> response,
+                                              std::shared_ptr<HttpServer::Request>) {
+        response->write(SimpleWeb::StatusCode::success_ok, "ok");
+    };
+
+    server.resource["^/v1/logs$"]["POST"] = [&captured](std::shared_ptr<HttpServer::Response> response,
+                                                        std::shared_ptr<HttpServer::Request> request) {
+        {
+            std::lock_guard<std::mutex> lock(captured.mutex);
+            captured.body = request->content.string();
+            captured.received = true;
+        }
+        captured.cv.notify_one();
+        response->write(SimpleWeb::StatusCode::success_ok, "{}");
+    };
+
+    std::thread server_thread([&server]() {
+        server.start();
+    });
+
+    assert(wait_for_server(port));
+
+    logit::OtlpHttpLoggerConfig config;
+    config.host = "http://127.0.0.1:" + std::to_string(port);
+    config.path = "/v1/logs";
+    config.service_name = "logit-otlp-test";
+    config.deployment_environment = "test";
+    config.max_batch_size = 8;
+    config.export_interval_ms = 50;
+    config.request_timeout_sec = 2;
+
+    LOGIT_ADD_LOGGER(
+        logit::OtlpHttpLogger,
+        (config),
+        logit::SimpleLogFormatter,
+        ("%v")
+    );
+
+    LOGIT_WARN("OTLP integration test message");
+    LOGIT_WAIT();
+
+    {
+        std::unique_lock<std::mutex> lock(captured.mutex);
+        captured.cv.wait_for(lock, std::chrono::seconds(3), [&captured]() {
+            return captured.received;
+        });
+    }
+
+    server.stop();
+    if (server_thread.joinable()) {
+        server_thread.join();
+    }
+
+    assert(captured.received);
+    assert(captured.body.find("\"resourceLogs\"") != std::string::npos);
+    assert(captured.body.find("\"service.name\",\"value\":{\"stringValue\":\"logit-otlp-test\"}") != std::string::npos);
+    assert(captured.body.find("\"deployment.environment.name\",\"value\":{\"stringValue\":\"test\"}") != std::string::npos);
+    assert(captured.body.find("\"severityText\":\"WARN\"") != std::string::npos);
+    assert(captured.body.find("\"severityNumber\":13") != std::string::npos);
+    assert(captured.body.find("OTLP integration test message") != std::string::npos);
+
+    return 0;
+}
+
+#else
+
+int main() {
+    return 0;
+}
+
+#endif