feat: Implement self-restart functionality for the agent

packages/debs/SPECS/wazuh-agent/debian/prerm

@@ -15,18 +15,9 @@ case "$1" in
       elif ${BINARY_DIR}wazuh-agent --status 2>/dev/null | grep "is running" > /dev/null 2>&1; then
           pid=$(ps -ef | grep "${BINARY_DIR}wazuh-agent" | grep -v grep | awk '{print $2}')
           if [ -n "$pid" ]; then
-              kill -SIGTERM "$pid" 2>/dev/null
+              kill -15 "$pid" 2>/dev/null
           fi
       fi
-
-      # # Process: wazuh-agent
-      # if pgrep -f "wazuh-agent" > /dev/null 2>&1; then
-      #   kill -15 $(pgrep -f "wazuh-agent") > /dev/null 2>&1
-      # fi
-
-      # if pgrep -f "wazuh-agent" > /dev/null 2>&1; then
-      #   kill -9 $(pgrep -f "wazuh-agent") > /dev/null 2>&1
-      # fi
     ;;
 
     remove)
@@ -38,10 +29,9 @@ case "$1" in
       elif ${BINARY_DIR}wazuh-agent --status 2>/dev/null | grep "is running" > /dev/null 2>&1; then
           pid=$(ps -ef | grep "${BINARY_DIR}wazuh-agent" | grep -v grep | awk '{print $2}')
           if [ -n "$pid" ]; then
-              kill -SIGTERM "$pid" 2>/dev/null
+              kill -15 "$pid" 2>/dev/null
           fi
       fi
-
     ;;
 
     failed-upgrade)
@@ -52,20 +42,9 @@ case "$1" in
       elif ${BINARY_DIR}wazuh-agent --status 2>/dev/null | grep "is running" > /dev/null 2>&1; then
           pid=$(ps -ef | grep "${BINARY_DIR}wazuh-agent" | grep -v grep | awk '{print $2}')
           if [ -n "$pid" ]; then
-              kill -SIGTERM "$pid" 2>/dev/null
+              kill -15 "$pid" 2>/dev/null
           fi
       fi
-
-      # if [ -f ${INSTALLATION_WAZUH_DIR}/bin/wazuh-agent ]; then
-      #   # pkill wazuh-agent
-      #   if pgrep -f "wazuh-agent" > /dev/null 2>&1; then
-      #     kill -15 $(pgrep -f "wazuh-agent") > /dev/null 2>&1
-      #   fi
-
-      #   if pgrep -f "wazuh-agent" > /dev/null 2>&1; then
-      #     kill -9 $(pgrep -f "wazuh-agent") > /dev/null 2>&1
-      #   fi
-      # fi
     ;;
 
     *)

src/agent/CMakeLists.txt

@@ -65,7 +65,6 @@ target_link_libraries(Agent
     MultiTypeQueue
     ModuleManager
     ModuleCommand
-    CentralizedConfiguration
     Boost::asio
     sysinfo
     PRIVATE

src/agent/command_handler/include/command_handler.hpp

@@ -123,8 +123,13 @@ namespace command_handler
             {
                 for (auto& cmd : *cmds)
                 {
-                    cmd.ExecutionResult.ErrorCode = module_command::Status::FAILURE;
-                    cmd.ExecutionResult.Message = "Agent stopped during execution";
+                    if (cmd.Command == "restart") {
+                        cmd.ExecutionResult.ErrorCode = module_command::Status::IN_PROGRESS;
+                        cmd.ExecutionResult.Message = "Restarting Agent...";
+                    } else {
+                        cmd.ExecutionResult.ErrorCode = module_command::Status::FAILURE;
+                        cmd.ExecutionResult.Message = "Agent stopped during execution";
+                    }
                     ReportCommandResult(cmd);
                     m_commandStore.UpdateCommand(cmd);
                 }

src/agent/command_handler/src/command_handler.cpp

@@ -3,7 +3,7 @@
 namespace command_handler
 {
     const std::unordered_map<std::string, std::string> VALID_COMMANDS_MAP = {
-        {"set-group", "CentralizedConfiguration"}, {"update-group", "CentralizedConfiguration"}};
+        {"set-group", "CentralizedConfiguration"}, {"update-group", "CentralizedConfiguration"}, {"restart", "restart"}};
 
     void CommandHandler::Stop()
     {

src/agent/include/agent.hpp

@@ -46,6 +46,12 @@ class Agent
     /// This method stops all modules launched by moduleManager, and starts them again.
     void ReloadModules();
 
+    /// @brief Checks if a restart is required
+    ///
+    /// This method returns `true` if the agent needs to be restarted,
+    /// and `false` otherwise.
+    bool IsRestartRequired();
+
 private:
     /// @brief Task manager
     TaskManager m_taskManager;
@@ -87,4 +93,7 @@ class Agent
 
     /// @brief Agent thread count
     size_t m_agentThreadCount;
+
+    /// @brief Define if the agent needs to be restarted after it ends.
+    bool requires_restart;
 };

src/agent/service/wazuh-agent.service

@@ -5,12 +5,13 @@ After=network.target network-online.target
 
 [Service]
 Type=simple
-
+PIDFile=/var/run/wazuh-agent.lock
 ExecStart=/usr/bin/env WAZUH_HOME/wazuh-agent
+TimeoutStopSec=30s    # Wait for 30 seconds before killing the service
 
 KillSignal=SIGTERM
 
-KillMode=process
+KillMode=mixed
 
 SendSIGKILL=no
 

src/agent/src/agent.cpp

@@ -13,7 +13,7 @@
 Agent::Agent(const std::string& configFilePath, std::unique_ptr<ISignalHandler> signalHandler)
     : m_configurationParser(configFilePath.empty() ? std::make_shared<configuration::ConfigurationParser>()
                                                    : std::make_shared<configuration::ConfigurationParser>(
-                                                         std::filesystem::path(configFilePath)))
+                                                        std::filesystem::path(configFilePath)))
     , m_dataPath(
           m_configurationParser->GetConfig<std::string>("agent", "path.data").value_or(config::DEFAULT_DATA_PATH))
     , m_messageQueue(std::make_shared<MultiTypeQueue>(
@@ -33,6 +33,7 @@ Agent::Agent(const std::string& configFilePath, std::unique_ptr<ISignalHandler>
                       m_configurationParser,
                       m_agentInfo.GetUUID())
     , m_commandHandler(m_dataPath)
+    , requires_restart(false)
 {
     // Check if agent is registered
     if (m_agentInfo.GetName().empty() || m_agentInfo.GetKey().empty() || m_agentInfo.GetUUID().empty())
@@ -101,6 +102,10 @@ void Agent::ReloadModules()
     }
 }
 
+bool Agent::IsRestartRequired(){
+    return requires_restart;
+}
+
 void Agent::Run()
 {
     m_taskManager.Start(m_agentThreadCount);
@@ -158,6 +163,16 @@ void Agent::Run()
                             return m_centralizedConfiguration.ExecuteCommand(std::move(command), std::move(parameters));
                         },
                         m_messageQueue);
+                } else if (cmd.Module == "restart") {
+                    requires_restart = true;
+                    SignalHandler::HandleSignal(SIGTERM);
+                    auto RestartExecuteCommand = []() -> boost::asio::awaitable<module_command::CommandExecutionResult> {
+                        co_return module_command::CommandExecutionResult{
+                            module_command::Status::IN_PROGRESS,
+                            "Pending restart execution"
+                        };
+                    };
+                    return RestartExecuteCommand();
                 }
                 return DispatchCommand(cmd, m_moduleManager.GetModule(cmd.Module), m_messageQueue);
             }),

src/agent/src/process_options_unix.cpp

@@ -13,6 +13,7 @@
 
 void StartAgent(const std::string& configFilePath)
 {
+    bool is_restart_required = false;
     unix_daemon::LockFileHandler lockFileHandler = unix_daemon::GenerateLockFile(configFilePath);
 
     if (!lockFileHandler.isLockFileCreated())
@@ -27,13 +28,18 @@ void StartAgent(const std::string& configFilePath)
     {
         Agent agent(configFilePath);
         agent.Run();
+        is_restart_required = agent.IsRestartRequired();
     }
     catch (const std::exception& e)
     {
         LogError("Exception thrown in wazuh-agent: {}", e.what());
     }
 
     lockFileHandler.removeLockFile();
+
+    if ( is_restart_required ){
+        LogInfo("## RESTARTING STARTED");
+    }
 }
 
 void StatusAgent(const std::string& configFilePath)

src/agent/src/unix/unix_daemon.cpp

@@ -86,8 +86,16 @@ namespace unix_daemon
             return false;
         }
 
-        LogDebug("Lock file created: {}", filename);
+        // Write the PID to the lock file
+        const std::string pidStr = std::to_string(getpid()) + "\n";
+        if (write(fd, pidStr.c_str(), pidStr.size()) == -1)
+        {
+            LogError("Unable to write PID to lock file: {}. Error: {} ({})", filename.c_str(), errno, std::strerror(errno));
+            close(fd);
+            return false;
+        }
 
+        LogDebug("Lock file created: {}", filename);
         return true;
     }