File

util/dependencies.lua @ 11523:5f15ab7c6ae5

Statistics: Rewrite statistics backends to use OpenMetrics The metric subsystem of Prosody has had some shortcomings from the perspective of the current state-of-the-art in metric observability. The OpenMetrics standard [0] is a formalization of the data model (and serialization format) of the well-known and widely-used Prometheus [1] software stack. The previous stats subsystem of Prosody did not map well to that format (see e.g. [2] and [3]); the key reason is that it was trying to do too much math on its own ([2]) while lacking first-class support for "families" of metrics ([3]) and structured metric metadata (despite the `extra` argument to metrics, there was no standard way of representing common things like "tags" or "labels"). Even though OpenMetrics has grown from the Prometheus world of monitoring, it maps well to other popular monitoring stacks such as: - InfluxDB (labels can be mapped to tags and fields as necessary) - Carbon/Graphite (labels can be attached to the metric name with dot-separation) - StatsD (see graphite when assuming that graphite is used as backend, which is the default) The util.statsd module has been ported to use the OpenMetrics model as a proof of concept. An implementation which exposes the util.statistics backend data as Prometheus metrics is ready for publishing in prosody-modules (most likely as mod_openmetrics_prometheus to avoid breaking existing 0.11 deployments). At the same time, the previous measure()-based API had one major advantage: It is really simple and easy to use without requiring lots of knowledge about OpenMetrics or similar concepts. For that reason as well as compatibility with existing code, it is preserved and may even be extended in the future. However, code relying on the `stats-updated` event as well as `get_stats` from `statsmanager` will break because the data model has changed completely; in case of `stats-updated`, the code will simply not run (as the event was renamed in order to avoid conflicts); the `get_stats` function has been removed completely (so it will cause a traceback when it is attempted to be used). Note that the measure_*_event methods have been removed from the module API. I was unable to find any uses or documentation and thus deemed they should not be ported. Re-implementation is possible when necessary. [0]: https://openmetrics.io/ [1]: https://prometheus.io/ [2]: #959 [3]: #960
author Jonas Schäfer <jonas@wielicki.name>
date Sun, 18 Apr 2021 11:47:41 +0200
parent 11141:a5acd6354845
child 11958:31f83a645ce6
line wrap: on
line source

-- 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 function softreq(...) local ok, lib =  pcall(require, ...); if ok then return lib; else return nil, lib; end end
local platform_table = require "util.human.io".table({ { width = 15, align = "right" }, { width = "100%" } });

-- Required to be able to find packages installed with luarocks
if not softreq "luarocks.loader" then -- LuaRocks 2.x
	softreq "luarocks.require"; -- LuaRocks <1.x
end

local function missingdep(name, sources, msg, err) -- luacheck: ignore err
	-- TODO print something about the underlying error, useful for debugging
	print("");
	print("**************************");
	print("Prosody was unable to find "..tostring(name));
	print("This package can be obtained in the following ways:");
	print("");
	for _, row in ipairs(sources) do
		print(platform_table(row));
	end
	print("");
	print(msg or (name.." is required for Prosody to run, so we will now exit."));
	print("More help can be found on our website, at https://prosody.im/doc/depends");
	print("**************************");
	print("");
end

local function check_dependencies()
	if _VERSION < "Lua 5.1" then
		print "***********************************"
		print("Unsupported Lua version: ".._VERSION);
		print("At least Lua 5.1 is required.");
		print "***********************************"
		return false;
	end

	local fatal;

	local lxp, err = softreq "lxp"

	if not lxp then
		missingdep("luaexpat", {
				{ "Debian/Ubuntu", "sudo apt-get install lua-expat" };
				{ "luarocks", "luarocks install luaexpat" };
				{ "Source", "http://matthewwild.co.uk/projects/luaexpat/" };
			}, nil, err);
		fatal = true;
	end

	local socket, err = softreq "socket"

	if not socket then
		missingdep("luasocket", {
				{ "Debian/Ubuntu", "sudo apt-get install lua-socket" };
				{ "luarocks", "luarocks install luasocket" };
				{ "Source", "http://www.tecgraf.puc-rio.br/~diego/professional/luasocket/" };
			}, nil, err);
		fatal = true;
	elseif not socket.tcp4 then
		-- COMPAT LuaSocket before being IP-version agnostic
		socket.tcp4 = socket.tcp;
		socket.udp4 = socket.udp;
	end

	local lfs, err = softreq "lfs"
	if not lfs then
		missingdep("luafilesystem", {
			{ "luarocks", "luarocks install luafilesystem" };
			{ "Debian/Ubuntu", "sudo apt-get install lua-filesystem" };
			{ "Source", "http://www.keplerproject.org/luafilesystem/" };
		}, nil, err);
		fatal = true;
	end

	local ssl, err = softreq "ssl"

	if not ssl then
		missingdep("LuaSec", {
				{ "Debian/Ubuntu", "sudo apt-get install lua-sec" };
				{ "luarocks", "luarocks install luasec" };
				{ "Source", "https://github.com/brunoos/luasec" };
			}, "SSL/TLS support will not be available", err);
	end

	local bit, err = softreq"util.bitcompat";

	if not bit then
		missingdep("lua-bitops", {
			{ "Debian/Ubuntu", "sudo apt-get install lua-bitop" };
			{ "luarocks", "luarocks install luabitop" };
			{ "Source", "http://bitop.luajit.org/" };
		}, "WebSocket support will not be available", err);
	end

	local unbound, err = softreq"lunbound"; -- luacheck: ignore 211/err
	if not unbound then -- luacheck: ignore 542
		--[[ TODO Re-enable once packages are available
		missingdep("lua-unbound", {
				{ "luarocks", "luarocks install luaunbound" };
				{ "Source", "https://www.zash.se/luaunbound.html" };
			}, "Old DNS resolver library will be used", err);
		--]]
	else
		package.preload["net.adns"] = function ()
			local ub = require "net.unbound";
			return ub;
		end
	end

	local encodings, err = softreq "util.encodings"
	if not encodings then
		if err:match("module '[^']*' not found") then
			missingdep("util.encodings", {
				{ "Windows", "Make sure you have encodings.dll from the Prosody distribution in util/" };
				{ "GNU/Linux", "Run './configure' and 'make' in the Prosody source directory to build util/encodings.so" };
			});
		else
			print "***********************************"
			print("util/encodings couldn't be loaded. Check that you have a recent version of libidn");
			print ""
			print("The full error was:");
			print(err)
			print "***********************************"
		end
		fatal = true;
	end

	local hashes, err = softreq "util.hashes"
	if not hashes then
		if err:match("module '[^']*' not found") then
			missingdep("util.hashes", {
				{ "Windows", "Make sure you have hashes.dll from the Prosody distribution in util/" };
				{ "GNU/Linux", "Run './configure' and 'make' in the Prosody source directory to build util/hashes.so" };
			});
		else
			print "***********************************"
			print("util/hashes couldn't be loaded. Check that you have a recent version of OpenSSL (libcrypto in particular)");
			print ""
			print("The full error was:");
			print(err)
			print "***********************************"
		end
		fatal = true;
	end

	return not fatal;
end

local function log_warnings()
	if _VERSION > "Lua 5.3" then
		prosody.log("warn", "Support for %s is experimental, please report any issues", _VERSION);
	end
	local ssl = softreq"ssl";
	if ssl then
		local major, minor, veryminor, patched = ssl._VERSION:match("(%d+)%.(%d+)%.?(%d*)(M?)");
		if not major or ((tonumber(major) == 0 and (tonumber(minor) or 0) <= 3 and (tonumber(veryminor) or 0) <= 2) and patched ~= "M") then
			prosody.log("error", "This version of LuaSec contains a known bug that causes disconnects, see https://prosody.im/doc/depends");
		end
	end
	local lxp = softreq"lxp";
	if lxp then
		if not pcall(lxp.new, { StartDoctypeDecl = false }) then
			prosody.log("error", "The version of LuaExpat on your system leaves Prosody "
				.."vulnerable to denial-of-service attacks. You should upgrade to "
				.."LuaExpat 1.3.0 or higher as soon as possible. See "
				.."https://prosody.im/doc/depends#luaexpat for more information.");
		end
		if not lxp.new({}).getcurrentbytecount then
			prosody.log("error", "The version of LuaExpat on your system does not support "
				.."stanza size limits, which may leave servers on untrusted "
				.."networks (e.g. the internet) vulnerable to denial-of-service "
				.."attacks. You should upgrade to LuaExpat 1.3.0 or higher as "
				.."soon as possible. See "
				.."https://prosody.im/doc/depends#luaexpat for more information.");
		end
	end
end

return {
	softreq = softreq;
	missingdep = missingdep;
	check_dependencies = check_dependencies;
	log_warnings = log_warnings;
};