Refactor everything to use prometheus-cpp

If only I had known about this earlier ;w;

CMakeLists.txt

@@ -11,12 +11,14 @@ option(NO_GUI "Build without GUI" OFF)
 option(STATIC_LINK "Link the binary statically" OFF)
 option(GTEST "Build with Google Test" OFF)
 option(ARM "Build for ARM" OFF)
+option(PROMETHEUS "Build with Prometheus support" ON)
 
 message(STATUS "Debugging network: ${DEBUG_NETWORK}")
 message(STATUS "Building without GUI: ${NO_GUI}")
 message(STATUS "Linking statically: ${STATIC_LINK}")
 message(STATUS "Building with Google Test: ${GTEST}")
 message(STATUS "Building for ARM: ${ARM}")
+message(STATUS "Building with Prometheus support: ${PROMETHEUS}")
 
 if (USE_CLANG)
     find_program(CLANG_EXECUTABLE clang REQUIRED)
@@ -152,6 +154,20 @@ target_include_directories(spdlog SYSTEM INTERFACE ${spdlog_include})
 get_target_property(yaml_cpp_include yaml-cpp INTERFACE_INCLUDE_DIRECTORIES)
 target_include_directories(yaml-cpp SYSTEM INTERFACE ${yaml_cpp_include})
 
+if(PROMETHEUS)
+    FetchContent_Declare(
+        prometheus-cpp
+        GIT_REPOSITORY https://github.com/jupp0r/prometheus-cpp.git
+        GIT_TAG v1.1.0
+        GIT_PROGRESS TRUE
+        GIT_SHALLOW TRUE
+    )
+
+    FetchContent_MakeAvailable(
+        prometheus-cpp
+    )
+endif()
+
 if(GTEST) # if the flag GTEST is true
     FetchContent_Declare(
         googletest
@@ -195,6 +211,7 @@ target_compile_definitions(${CMAKE_PROJECT_NAME} PRIVATE
     PROGRAM_VERSION="${CMAKE_PROJECT_VERSION}"
     MINECRAFT_VERSION="${MINECRAFT_VERSION}"
     GUI_UNAVAILABLE=$<BOOL:${NO_GUI}>
+    PROMETHEUS_SUPPORT=$<BOOL:${PROMETHEUS}>
 )
 
 if (STATIC_LINK)
@@ -237,6 +254,10 @@ target_link_libraries (${CMAKE_PROJECT_NAME} PRIVATE
     $<$<NOT:$<BOOL:${Boost_FOUND}>>:Boost::circular_buffer>
 )
 
+if (PROMETHEUS)
+target_link_libraries (${CMAKE_PROJECT_NAME} PRIVATE prometheus-cpp::pull)
+endif ()
+
 if (CMAKE_BUILD_TYPE MATCHES RELWITHDEBINFO)
     target_link_libraries (${CMAKE_PROJECT_NAME} PRIVATE
         asan

cubic-server/CMakeLists.txt

@@ -47,6 +47,13 @@ target_sources (${CMAKE_PROJECT_NAME} PRIVATE
     CompressionUtils.hpp
 )
 
+if(PROMETHEUS)
+target_sources (${CMAKE_PROJECT_NAME} PRIVATE
+    PrometheusExporter.cpp
+    PrometheusExporter.hpp
+)
+endif()
+
 file(MAKE_DIRECTORY ${CMAKE_BINARY_DIR}/plugins)
 
 if (GTEST)
@@ -110,4 +117,3 @@ add_subdirectory (scoreboard)
 add_subdirectory (registry)
 add_subdirectory (entities)
 add_subdirectory (ai)
-add_subdirectory (http)

cubic-server/PrometheusExporter.cpp

@@ -0,0 +1,29 @@
+#include <memory>
+
+#include <prometheus/counter.h>
+#include <prometheus/registry.h>
+
+#include "PrometheusExporter.hpp"
+#include "options.hpp"
+
+PrometheusExporter::PrometheusExporter(const std::string &bind):
+    _exposer(bind)
+{
+}
+
+void PrometheusExporter::registerMetrics()
+{
+    _registry = std::make_shared<prometheus::Registry>();
+
+    // Just an example of what you can put here
+    // To add anything else to the metrics follow the readme of prometheus-cpp:
+    // https://github.com/jupp0r/prometheus-cpp/blob/master/README.md
+    // clang-format off
+    UNUSED auto &packet_counter = prometheus::BuildCounter()
+        .Name("observed_packets_total")
+        .Help("Number of observed packets")
+        .Register(*_registry);
+    // clang-format on
+
+    _exposer.RegisterCollectable(_registry);
+}

cubic-server/PrometheusExporter.hpp

@@ -0,0 +1,20 @@
+#ifndef D5AEBC4C_6028_4506_86F2_DA6261F54832
+#define D5AEBC4C_6028_4506_86F2_DA6261F54832
+
+#include <memory>
+#include <string>
+
+#include "prometheus/exposer.h"
+#include "prometheus/registry.h"
+
+class PrometheusExporter {
+public:
+    PrometheusExporter(const std::string &bind);
+    void registerMetrics();
+
+private:
+    prometheus::Exposer _exposer;
+    std::shared_ptr<prometheus::Registry> _registry;
+};
+
+#endif /* D5AEBC4C_6028_4506_86F2_DA6261F54832 */

cubic-server/Server.cpp

@@ -14,6 +14,7 @@
 
 #include <mbedtls/rsa.h>
 
+#include "PrometheusExporter.hpp"
 #include "Server.hpp"
 #include "World.hpp"
 
@@ -26,7 +27,6 @@
 #include "command_parser/commands/InventoryDump.hpp"
 #include "command_parser/commands/Teleport.hpp"
 #include "default/DefaultWorldGroup.hpp"
-#include "http/HttpServer.hpp"
 #include "logging/logging.hpp"
 #include "registry/Biome.hpp"
 #include "registry/Chat.hpp"
@@ -38,20 +38,10 @@ using boost::asio::ip::tcp;
 
 Server::Server():
     _running(false),
-    // _sockfd(-1),
     _config(),
     _pluginManager(this),
     _toSend(1024)
 {
-    // _config.load("./config.yml");
-    // _config.parse("./config.yml");
-    // _config.parse(2, (const char * const *){"./CubicServer", "--nogui"});
-    // _host = _config.getIP();
-    // _port = _config.getPort();
-    // _maxPlayer = _config.getMaxPlayers();
-    // _motd = _config.getMotd();
-    // _enforceWhitelist = _config.getEnforceWhitelist();
-
     _commands.emplace_back(std::make_unique<command_parser::Help>());
     _commands.emplace_back(std::make_unique<command_parser::QuestionMark>());
     _commands.emplace_back(std::make_unique<command_parser::Stop>());
@@ -166,8 +156,10 @@ void Server::launch(const configuration::ConfigHandler &config)
 
     _writeThread = std::thread(&Server::_writeLoop, this);
 
-    // http stuff
-    _httpThread = std::thread(http::launchHttpServer);
+    if (CONFIG["monitoring-prometheus-enable"].as<bool>()) {
+        _prometheusExporter = std::make_unique<PrometheusExporter>("0.0.0.0:4242");
+        _prometheusExporter->registerMetrics();
+    }
 
     _doAccept();
 
@@ -229,15 +221,6 @@ void Server::triggerClientCleanup(size_t clientID)
         _clients.erase(clientID);
         return;
     }
-    // boost::lockfree::queue<size_t> toDelete(_clients.size());
-    // for (auto [id, cli] : _clients) {
-    //     if (!cli) {
-    //         _clients.erase(id);
-    //     } else if (cli->isDisconnected()) {
-    //         cli->getThread().join();
-    //         _clients.erase(id);
-    //     }
-    // }
     std::erase_if(_clients, [](const auto augh) {
         if (augh.second->isDisconnected()) {
             if (augh.second->getThread().joinable())
@@ -252,17 +235,6 @@ void Server::addCommand(std::unique_ptr<CommandBase> command) { this->_commands.
 
 void Server::_doAccept()
 {
-    // while (_running) {
-    //     boost::system::error_code ec;
-    //     tcp::socket socket(_io_context);
-
-    //     _acceptor->accept(socket, ec);
-    //     if (!ec) {
-    //         std::shared_ptr<Client> _cli(new Client(std::move(socket), currentClientID));
-    //         _clients.emplace(currentClientID++, _cli);
-    //         _cli->run();
-    //     }
-    // }
     tcp::socket *socket = new tcp::socket(_io_context);
 
     _acceptor->async_accept(*socket, [socket, this](const boost::system::error_code &error) {
@@ -274,10 +246,6 @@ void Server::_doAccept()
         }
         delete socket;
         if (this->_running) {
-            // for (auto [id, cli] : _clients) {
-            //     if (!cli || cli->isDisconnected()) // Somehow they can already be freed before we get here...
-            //         _clients.erase(id);
-            // }
             this->_doAccept();
         }
     });

cubic-server/Server.hpp

@@ -43,6 +43,10 @@
 
 #include "registry/MasterRegistry.hpp"
 
+#if PROMETHEUS_SUPPORT == 1
+#include "PrometheusExporter.hpp"
+#endif
+
 constexpr char MC_VERSION[] = "1.19.3";
 constexpr char MC_VERSION_BRANDING[] = "CubicServer 1.19.3";
 constexpr uint16_t MC_PROTOCOL = 761;
@@ -155,8 +159,13 @@ class Server {
 
     RSAEncryptionHandler _rsaKey;
 
-    // http stuff
-    std::thread _httpThread;
+#if PROMETHEUS_SUPPORT == 1
+    std::unique_ptr<PrometheusExporter> _prometheusExporter;
+
+public:
+    NODISCARD inline const PrometheusExporter &getPrometheusExporter() const { return *_prometheusExporter; }
+    NODISCARD inline PrometheusExporter &getPrometheusExporter() { return *_prometheusExporter; }
+#endif
 
 public:
     NODISCARD inline bool isCompressed() const { return _config["compression"].as<bool>(); }