File

plugins/mod_posix.lua @ 10228:e77bf4222fae

net.server_epoll: Add support for opportunistic writes This tries to flush data to the underlying sockets when receiving writes. This should lead to fewer timer objects being around. On the other hand, this leads to more and smaller writes which may translate to more TCP/IP packets being sent, depending on how the kernel handles this. This trades throughput for lower latency.
author Kim Alvefur <zash@zash.se>
date Wed, 28 Aug 2019 01:41:00 +0200
parent 9928:d92ab8c8006a
child 10599:4f655918fef1
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-- Prosody IM
-- Copyright (C) 2008-2010 Matthew Wild
-- Copyright (C) 2008-2010 Waqas Hussain
--
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--


local want_pposix_version = "0.4.0";

local pposix = assert(require "util.pposix");
if pposix._VERSION ~= want_pposix_version then
	module:log("warn", "Unknown version (%s) of binary pposix module, expected %s."
		.. "Perhaps you need to recompile?", tostring(pposix._VERSION), want_pposix_version);
end

local have_signal, signal = pcall(require, "util.signal");
if not have_signal then
	module:log("warn", "Couldn't load signal library, won't respond to SIGTERM");
end

local lfs = require "lfs";
local stat = lfs.attributes;

local prosody = _G.prosody;

module:set_global(); -- we're a global module

local umask = module:get_option_string("umask", "027");
pposix.umask(umask);

-- Allow switching away from root, some people like strange ports.
module:hook("server-started", function ()
	local uid = module:get_option("setuid");
	local gid = module:get_option("setgid");
	if gid then
		local success, msg = pposix.setgid(gid);
		if success then
			module:log("debug", "Changed group to %s successfully.", gid);
		else
			module:log("error", "Failed to change group to %s. Error: %s", gid, msg);
			prosody.shutdown("Failed to change group to %s", gid);
		end
	end
	if uid then
		local success, msg = pposix.setuid(uid);
		if success then
			module:log("debug", "Changed user to %s successfully.", uid);
		else
			module:log("error", "Failed to change user to %s. Error: %s", uid, msg);
			prosody.shutdown("Failed to change user to %s", uid);
		end
	end
end);

-- Don't even think about it!
if not prosody.start_time then -- server-starting
	local suid = module:get_option("setuid");
	if not suid or suid == 0 or suid == "root" then
		if pposix.getuid() == 0 and not module:get_option_boolean("run_as_root") then
			module:log("error", "Danger, Will Robinson! Prosody doesn't need to be run as root, so don't do it!");
			module:log("error", "For more information on running Prosody as root, see https://prosody.im/doc/root");
			prosody.shutdown("Refusing to run as root");
		end
	end
end

local pidfile;
local pidfile_handle;

local function remove_pidfile()
	if pidfile_handle then
		pidfile_handle:close();
		os.remove(pidfile);
		pidfile, pidfile_handle = nil, nil;
	end
end

local function write_pidfile()
	if pidfile_handle then
		remove_pidfile();
	end
	pidfile = module:get_option_path("pidfile", nil, "data");
	if pidfile then
		local err;
		local mode = stat(pidfile) and "r+" or "w+";
		pidfile_handle, err = io.open(pidfile, mode);
		if not pidfile_handle then
			module:log("error", "Couldn't write pidfile at %s; %s", pidfile, err);
			prosody.shutdown("Couldn't write pidfile");
		else
			if not lfs.lock(pidfile_handle, "w") then -- Exclusive lock
				local other_pid = pidfile_handle:read("*a");
				module:log("error", "Another Prosody instance seems to be running with PID %s, quitting", other_pid);
				pidfile_handle = nil;
				prosody.shutdown("Prosody already running");
			else
				pidfile_handle:close();
				pidfile_handle, err = io.open(pidfile, "w+");
				if not pidfile_handle then
					module:log("error", "Couldn't write pidfile at %s; %s", pidfile, err);
					prosody.shutdown("Couldn't write pidfile");
				else
					if lfs.lock(pidfile_handle, "w") then
						pidfile_handle:write(tostring(pposix.getpid()));
						pidfile_handle:flush();
					end
				end
			end
		end
	end
end

local daemonize = module:get_option("daemonize", prosody.installed);

local function remove_log_sinks()
	local lm = require "core.loggingmanager";
	lm.register_sink_type("console", nil);
	lm.register_sink_type("stdout", nil);
	lm.reload_logging();
end

if daemonize then
	local function daemonize_server()
		module:log("info", "Prosody is about to detach from the console, disabling further console output");
		remove_log_sinks();
		local ok, ret = pposix.daemonize();
		if not ok then
			module:log("error", "Failed to daemonize: %s", ret);
		elseif ret and ret > 0 then
			os.exit(0);
		else
			module:log("info", "Successfully daemonized to PID %d", pposix.getpid());
			write_pidfile();
		end
	end
	if not prosody.start_time then -- server-starting
		daemonize_server();
	end
else
	-- Not going to daemonize, so write the pid of this process
	write_pidfile();
end

module:hook("server-stopped", remove_pidfile);

-- Set signal handlers
if have_signal then
	module:add_timer(0, function ()
		signal.signal("SIGTERM", function ()
			module:log("warn", "Received SIGTERM");
			prosody.unlock_globals();
			prosody.shutdown("Received SIGTERM");
			prosody.lock_globals();
		end);

		signal.signal("SIGHUP", function ()
			module:log("info", "Received SIGHUP");
			prosody.reload_config();
			-- this also reloads logging
		end);

		signal.signal("SIGINT", function ()
			module:log("info", "Received SIGINT");
			prosody.unlock_globals();
			prosody.shutdown("Received SIGINT");
			prosody.lock_globals();
		end);
	end);
end