File

core/hostmanager.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 11505:61d38c4b749d
child 12972:ead41e25ebc0
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 configmanager = require "core.configmanager";
local modulemanager = require "core.modulemanager";
local events_new = require "util.events".new;
local disco_items = require "util.multitable".new();
local NULL = {};

local log = require "util.logger".init("hostmanager");

local hosts = prosody.hosts;
local prosody_events = prosody.events;
if not _G.prosody.incoming_s2s then
	require "core.s2smanager";
end
local incoming_s2s = _G.prosody.incoming_s2s;
local core_route_stanza = _G.prosody.core_route_stanza;

local pairs, rawget = pairs, rawget;
local tostring, type = tostring, type;
local setmetatable = setmetatable;

local _ENV = nil;
-- luacheck: std none

local host_mt = { }
function host_mt:__tostring()
	if self.type == "component" then
		local typ = configmanager.get(self.host, "component_module");
		if typ == "component" then
			return ("Component %q"):format(self.host);
		end
		return ("Component %q %q"):format(self.host, typ);
	elseif self.type == "local" then
		return ("VirtualHost %q"):format(self.host);
	end
end

local hosts_loaded_once;

local activate, deactivate;

local function load_enabled_hosts(config)
	local defined_hosts = config or configmanager.getconfig();
	local activated_any_host;

	for host, host_config in pairs(defined_hosts) do
		if host ~= "*" and host_config.enabled ~= false then
			if not host_config.component_module then
				activated_any_host = true;
			end
			activate(host, host_config);
		end
	end

	if not activated_any_host then
		log("error", "No active VirtualHost entries in the config file. This may cause unexpected behaviour as no modules will be loaded.");
	end

	prosody_events.fire_event("hosts-activated", defined_hosts);
	hosts_loaded_once = true;
end

prosody_events.add_handler("server-starting", load_enabled_hosts);

local function host_send(stanza)
	core_route_stanza(nil, stanza);
end

function activate(host, host_config)
	if rawget(hosts, host) then return nil, "The host "..host.." is already activated"; end
	host_config = host_config or configmanager.getconfig()[host];
	if not host_config then return nil, "Couldn't find the host "..tostring(host).." defined in the current config"; end
	local host_session = {
		host = host;
		s2sout = {};
		events = events_new();
		send = host_send;
		modules = {};
	};
	function host_session:close(reason)
		log("debug", "Attempt to close host session %s with reason: %s", self.host, reason);
	end
	setmetatable(host_session, host_mt);
	if not host_config.component_module then -- host
		host_session.type = "local";
		host_session.sessions = {};
	else -- component
		host_session.type = "component";
	end
	hosts[host] = host_session;
	if not host_config.disco_hidden and not host:match("[@/]") then
		disco_items:set(host:match("%.(.*)") or "*", host, host_config.name or true);
	end
	for option_name in pairs(host_config) do
		if option_name:match("_ports$") or option_name:match("_interface$") then
			log("warn", "%s: Option '%s' has no effect for virtual hosts - put it in the server-wide section instead", host, option_name);
		end
	end

	log((hosts_loaded_once and "info") or "debug", "Activated host: %s", host);
	prosody_events.fire_event("host-activated", host);
	return true;
end

function deactivate(host, reason)
	local host_session = hosts[host];
	if not host_session then return nil, "The host "..tostring(host).." is not activated"; end
	log("info", "Deactivating host: %s", host);
	prosody_events.fire_event("host-deactivating", { host = host, host_session = host_session, reason = reason });

	if type(reason) ~= "table" then
		reason = { condition = "host-gone", text = tostring(reason or "This server has stopped serving "..host) };
	end

	-- Disconnect local users, s2s connections
	-- TODO: These should move to mod_c2s and mod_s2s (how do they know they're being unloaded and not reloaded?)
	if host_session.sessions then
		for username, user in pairs(host_session.sessions) do
			for resource, session in pairs(user.sessions) do
				log("debug", "Closing connection for %s@%s/%s", username, host, resource);
				session:close(reason);
			end
		end
	end
	if host_session.s2sout then
		for remotehost, session in pairs(host_session.s2sout) do
			if session.close then
				log("debug", "Closing outgoing connection to %s", remotehost);
				session:close(reason);
			end
		end
	end
	for remote_session in pairs(incoming_s2s) do
		if remote_session.to_host == host then
			log("debug", "Closing incoming connection from %s", remote_session.from_host or "<unknown>");
			remote_session:close(reason);
		end
	end

	-- TODO: This should be done in modulemanager
	if host_session.modules then
		for module in pairs(host_session.modules) do
			modulemanager.unload(host, module);
		end
	end

	hosts[host] = nil;
	if not host:match("[@/]") then
		disco_items:remove(host:match("%.(.*)") or "*", host);
	end
	prosody_events.fire_event("host-deactivated", host);
	log("info", "Deactivated host: %s", host);
	return true;
end

local function get_children(host)
	return disco_items:get(host) or NULL;
end

return {
	activate = activate;
	deactivate = deactivate;
	get_children = get_children;
}