Merge pull request #7874 from Icinga/feature/sd_notify-7329

sd_notify() systemd about what we're doing right now

etc/initsystem/icinga2.service.cmake

@@ -5,6 +5,7 @@ After=syslog.target network-online.target postgresql.service mariadb.service car
 
 [Service]
 Type=notify
+NotifyAccess=all
 Environment="ICINGA2_ERROR_LOG=@ICINGA2_LOGDIR@/error.log"
 EnvironmentFile=@ICINGA2_SYSCONFIGFILE@
 ExecStartPre=@CMAKE_INSTALL_PREFIX@/lib/icinga2/prepare-dirs @ICINGA2_SYSCONFIGFILE@

lib/base/process.cpp

@@ -105,6 +105,7 @@ static Value ProcessSpawnImpl(struct msghdr *msgh, const Dictionary::Ptr& reques
 
 	auto **envp = new char *[envc + (extraEnvironment ? extraEnvironment->GetLength() : 0) + 2];
 	const char* lcnumeric = "LC_NUMERIC=";
+	const char* notifySocket = "NOTIFY_SOCKET=";
 	int j = 0;
 
 	for (int i = 0; i < envc; i++) {
@@ -112,6 +113,10 @@ static Value ProcessSpawnImpl(struct msghdr *msgh, const Dictionary::Ptr& reques
 			continue;
 		}
 
+		if (strncmp(environ[i], notifySocket, strlen(notifySocket)) == 0) {
+			continue;
+		}
+
 		envp[j] = strdup(environ[i]);
 		++j;
 	}

lib/cli/daemoncommand.cpp

@@ -45,6 +45,14 @@ static po::variables_map g_AppParams;
 
 REGISTER_CLICOMMAND("daemon", DaemonCommand);
 
+static inline
+void NotifyStatus(const char* status)
+{
+#ifdef HAVE_SYSTEMD
+	(void)sd_notifyf(0, "STATUS=%s", status);
+#endif /* HAVE_SYSTEMD */
+}
+
 /*
  * Daemonize().  On error, this function logs by itself and exits (i.e. does not return).
  *
@@ -235,12 +243,14 @@ int RunWorker(const std::vector<std::string>& configs, bool closeConsoleLog = fa
 #endif /* I2_DEBUG */
 
 	Log(LogInformation, "cli", "Loading configuration file(s).");
+	NotifyStatus("Loading configuration file(s)...");
 
 	{
 		std::vector<ConfigItem::Ptr> newItems;
 
 		if (!DaemonUtility::LoadConfigFiles(configs, newItems, Configuration::ObjectsPath, Configuration::VarsPath)) {
 			Log(LogCritical, "cli", "Config validation failed. Re-run with 'icinga2 daemon -C' after fixing the config.");
+			NotifyStatus("Config validation failed.");
 			return EXIT_FAILURE;
 		}
 
@@ -253,6 +263,8 @@ int RunWorker(const std::vector<std::string>& configs, bool closeConsoleLog = fa
 		Log(LogNotice, "cli")
 			<< "Waiting for the umbrella process to let us doing the actual work";
 
+		NotifyStatus("Waiting for the umbrella process to let us doing the actual work...");
+
 		if (closeConsoleLog) {
 			CloseStdIO(stderrFile);
 			Logger::DisableConsoleLog();
@@ -266,18 +278,28 @@ int RunWorker(const std::vector<std::string>& configs, bool closeConsoleLog = fa
 			<< "The umbrella process let us continuing";
 #endif /* _WIN32 */
 
+		NotifyStatus("Restoring the previous program state...");
+
 		/* restore the previous program state */
 		try {
 			ConfigObject::RestoreObjects(Configuration::StatePath);
 		} catch (const std::exception& ex) {
 			Log(LogCritical, "cli")
 				<< "Failed to restore state file: " << DiagnosticInformation(ex);
+
+			NotifyStatus("Failed to restore state file.");
+
 			return EXIT_FAILURE;
 		}
 
+		NotifyStatus("Activating config objects...");
+
 		// activate config only after daemonization: it starts threads and that is not compatible with fork()
 		if (!ConfigItem::ActivateItems(newItems, false, true, true)) {
 			Log(LogCritical, "cli", "Error activating configuration.");
+
+			NotifyStatus("Error activating configuration.");
+
 			return EXIT_FAILURE;
 		}
 	}
@@ -296,6 +318,8 @@ int RunWorker(const std::vector<std::string>& configs, bool closeConsoleLog = fa
 
 	ApiListener::UpdateObjectAuthority();
 
+	NotifyStatus("Startup finished.");
+
 	return Application::GetInstance()->Run();
 }
 
@@ -796,6 +820,8 @@ int DaemonCommand::Run(const po::variables_map& vm, const std::vector<std::strin
 					Log(LogInformation, "Application")
 						<< "Reload done, old process shutting down. Child process with PID '" << nextWorker << "' is taking over.";
 
+					NotifyStatus("Shutting down old instance...");
+
 					(void)kill(currentWorker, SIGTERM);
 
 					{
@@ -814,6 +840,8 @@ int DaemonCommand::Run(const po::variables_map& vm, const std::vector<std::strin
 					// Old instance shut down, allow the new one to continue working beyond config validation
 					(void)kill(nextWorker, SIGUSR2);
 
+					NotifyStatus("Shut down old instance.");
+
 					currentWorker = nextWorker;
 			}