scord-ctl: Write pidfiles on demand (5f261433) · Commits · eu / ADMIRE / scord

src/common/net/server.cpp

+50 −36

Original line number	Diff line number	Diff line
		@@ -44,14 +44,51 @@

		using namespace std::literals;

		namespace {
		void
		write_pidfile(const std::filesystem::path& pidfile) {

		int fd;

		if((fd = ::open(pidfile.c_str(), O_RDWR \| O_CREAT, 0640)) == -1) {
		throw std::system_error(errno, std::system_category(),
		"Failed to create daemon lock file");
		}

		if(::lockf(fd, F_TLOCK, 0) < 0) {
		throw std::system_error(errno, std::system_category(),
		"Failed to acquire lock on pidfile. Another "
		"instance of this daemon may already be "
		"running");
		}

		/* record pid in lockfile */
		std::string pidstr(std::to_string(getpid()));

		if(::write(fd, pidstr.c_str(), pidstr.length()) !=
		static_cast<ssize_t>(pidstr.length())) {
		throw std::system_error(errno, std::system_category(),
		"Failed to write pidfile");
		}

		/* flush changes */
		::fsync(fd);
		::fdatasync(fd);

		::close(fd);
		}
		} // namespace

		namespace network {

		server::server(std::string name, std::string address, bool daemonize,
		std::filesystem::path rundir)
		std::filesystem::path rundir,
		std::optional<std::filesystem::path> pidfile)

		: m_name(std::move(name)), m_address(std::move(address)),
		m_daemonize(daemonize), m_rundir(std::move(rundir)),
		m_pidfile(daemonize ? std::make_optional(m_rundir / (m_name + ".pid"))
		: std::nullopt),
		: std::move(pidfile)),
		m_logger_config(m_name, logger::logger_type::console_color),
		m_network_engine(m_address, THALLIUM_SERVER_MODE) {}

		@@ -150,39 +187,6 @@ server::daemonize() {
		exit(EXIT_FAILURE);
		}

		/* Check if daemon already exists:
		* First instance of the daemon will lock the file so that other
		* instances understand that an instance is already running.
		*/
		int pfd;

		if(!m_pidfile.has_value()) {
		LOGGER_ERROR("Daemon lock file not specified");
		exit(EXIT_FAILURE);
		}

		if((pfd = ::open(m_pidfile->string().c_str(), O_RDWR \| O_CREAT, 0640)) ==
		-1) {
		LOGGER_ERRNO("Failed to create daemon lock file");
		exit(EXIT_FAILURE);
		}

		if(::lockf(pfd, F_TLOCK, 0) < 0) {
		LOGGER_ERRNO("Failed to acquire lock on pidfile");
		LOGGER_ERROR("Another instance of this daemon may already be running");
		exit(EXIT_FAILURE);
		}

		/* record pid in lockfile */
		std::string pidstr(std::to_string(getpid()));

		if(::write(pfd, pidstr.c_str(), pidstr.length()) !=
		static_cast<ssize_t>(pidstr.length())) {
		LOGGER_ERRNO("Failed to write pidfile");
		exit(EXIT_FAILURE);
		}

		::close(pfd);
		::close(dev_null);

		/* Manage signals */
		@@ -324,6 +328,16 @@ server::run() {
		return EXIT_SUCCESS;
		}

		// write pidfile if needed
		if(m_pidfile.has_value()) {
		try {
		::write_pidfile(m_pidfile.value());
		} catch(const std::system_error& e) {
		LOGGER_ERROR("Failed to create pidfile: {}", e.what());
		return EXIT_FAILURE;
		}
		}

		// print useful information
		print_greeting();
		print_configuration();
		@@ -354,7 +368,7 @@ server::teardown() {
		LOGGER_INFO("* Stopping signal listener...");
		m_signal_listener.stop();

		if(!m_daemonize \|\| !m_pidfile) {
		if(!m_daemonize) {
		return;
		}

src/common/net/server.hpp

+2 −1

Original line number	Diff line number	Diff line
		@@ -46,7 +46,8 @@ class server {

		public:
		server(std::string name, std::string address, bool daemonize,
		std::filesystem::path rundir);
		std::filesystem::path rundir,
		std::optional<std::filesystem::path> pidfile = {});

		~server();

src/scord-ctl/rpc_server.cpp

+3 −2

Original line number	Diff line number	Diff line
		@@ -34,9 +34,10 @@ using namespace std::literals;
		namespace scord_ctl {

		rpc_server::rpc_server(std::string name, std::string address, bool daemonize,
		std::filesystem::path rundir)
		std::filesystem::path rundir,
		std::optional<std::filesystem::path> pidfile)
		: server::server(std::move(name), std::move(address), std::move(daemonize),
		std::move(rundir)),
		std::move(rundir), std::move(pidfile)),
		provider::provider(m_network_engine, 0) {

		#define EXPAND(rpc_name) "ADM_" #rpc_name##s, &rpc_server::rpc_name

src/scord-ctl/rpc_server.hpp

+2 −1

Original line number	Diff line number	Diff line
		@@ -37,7 +37,8 @@ class rpc_server : public network::server,

		public:
		rpc_server(std::string name, std::string address, bool daemonize,
		std::filesystem::path rundir);
		std::filesystem::path rundir,
		std::optional<std::filesystem::path> pidfile = {});

		void
		set_config(std::optional<config::config_file> config);

src/scord-ctl/scord_ctl.cpp

+6 −1

Original line number	Diff line number	Diff line
		@@ -46,6 +46,7 @@ main(int argc, char* argv[]) {
		struct {
		std::optional<fs::path> output_file;
		std::string address;
		std::optional<fs::path> pidfile;
		} cli_args;

		const auto progname = fs::path{argv[0]}.filename().string();
		@@ -67,6 +68,10 @@ main(int argc, char* argv[]) {
		->option_text("ADDRESS")
		->required();

		app.add_option("-p,--pidfile", cli_args.pidfile,
		"Write the daemon's PID to FILENAME")
		->option_text("FILENAME");

		app.set_config("-c,--config-file", scord_ctl::config::defaults::config_file,
		"Ignore the system-wide configuration file and use the "
		"configuration provided by FILENAME",
		@@ -91,7 +96,7 @@ main(int argc, char* argv[]) {
		app.get_config_ptr()->as<fs::path>());

		scord_ctl::rpc_server srv(progname, cli_args.address, false,
		fs::current_path());
		fs::current_path(), cli_args.pidfile);
		if(cli_args.output_file) {
		srv.configure_logger(logger::logger_type::file,
		*cli_args.output_file);