File

plugins/mod_roster.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 8646:a267dfa9d81d
child 12100:0b14b541fd27
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 st = require "util.stanza"

local jid_split = require "util.jid".split;
local jid_prep = require "util.jid".prep;
local tonumber = tonumber;
local pairs = pairs;

local rm_load_roster = require "core.rostermanager".load_roster;
local rm_remove_from_roster = require "core.rostermanager".remove_from_roster;
local rm_add_to_roster = require "core.rostermanager".add_to_roster;
local rm_roster_push = require "core.rostermanager".roster_push;

module:add_feature("jabber:iq:roster");

local rosterver_stream_feature = st.stanza("ver", {xmlns="urn:xmpp:features:rosterver"});
module:hook("stream-features", function(event)
	local origin, features = event.origin, event.features;
	if origin.username then
		features:add_child(rosterver_stream_feature);
	end
end);

module:hook("iq/self/jabber:iq:roster:query", function(event)
	local session, stanza = event.origin, event.stanza;

	if stanza.attr.type == "get" then
		local roster = st.reply(stanza);

		local client_ver = tonumber(stanza.tags[1].attr.ver);
		local server_ver = tonumber(session.roster[false].version or 1);

		if not (client_ver and server_ver) or client_ver ~= server_ver then
			roster:query("jabber:iq:roster");
			-- Client does not support versioning, or has stale roster
			for jid, item in pairs(session.roster) do
				if jid then
					roster:tag("item", {
						jid = jid,
						subscription = item.subscription,
						ask = item.ask,
						name = item.name,
					});
					for group in pairs(item.groups) do
						roster:text_tag("group", group);
					end
					roster:up(); -- move out from item
				end
			end
			roster.tags[1].attr.ver = server_ver;
		end
		session.send(roster);
		session.interested = true; -- resource is interested in roster updates
	else -- stanza.attr.type == "set"
		local query = stanza.tags[1];
		if #query.tags == 1 and query.tags[1].name == "item"
				and query.tags[1].attr.xmlns == "jabber:iq:roster" and query.tags[1].attr.jid then
			local item = query.tags[1];
			local from_node, from_host = jid_split(stanza.attr.from);
			local jid = jid_prep(item.attr.jid);
			local node, host, resource = jid_split(jid);
			if not resource and host then
				if jid ~= from_node.."@"..from_host then
					if item.attr.subscription == "remove" then
						local roster = session.roster;
						local r_item = roster[jid];
						if r_item then
							module:fire_event("roster-item-removed", {
								username = node, jid = jid, item = r_item, origin = session, roster = roster,
							});
							local success, err_type, err_cond, err_msg = rm_remove_from_roster(session, jid);
							if success then
								session.send(st.reply(stanza));
								rm_roster_push(from_node, from_host, jid);
							else
								session.send(st.error_reply(stanza, err_type, err_cond, err_msg));
							end
						else
							session.send(st.error_reply(stanza, "modify", "item-not-found"));
						end
					else
						local r_item = {name = item.attr.name, groups = {}};
						if r_item.name == "" then r_item.name = nil; end
						if session.roster[jid] then
							r_item.subscription = session.roster[jid].subscription;
							r_item.ask = session.roster[jid].ask;
						else
							r_item.subscription = "none";
						end
						for group in item:childtags("group") do
							local text = group:get_text();
							if text then
								r_item.groups[text] = true;
							end
						end
						local success, err_type, err_cond, err_msg = rm_add_to_roster(session, jid, r_item);
						if success then
							-- Ok, send success
							session.send(st.reply(stanza));
							-- and push change to all resources
							rm_roster_push(from_node, from_host, jid);
						else
							-- Adding to roster failed
							session.send(st.error_reply(stanza, err_type, err_cond, err_msg));
						end
					end
				else
					-- Trying to add self to roster
					session.send(st.error_reply(stanza, "cancel", "not-allowed"));
				end
			else
				-- Invalid JID added to roster
				session.send(st.error_reply(stanza, "modify", "bad-request")); -- FIXME what's the correct error?
			end
		else
			-- Roster set didn't include a single item, or its name wasn't  'item'
			session.send(st.error_reply(stanza, "modify", "bad-request"));
		end
	end
	return true;
end);

module:hook_global("user-deleted", function(event)
	local username, host = event.username, event.host;
	local origin = event.origin or prosody.hosts[host];
	if host ~= module.host then return end
	local roster = rm_load_roster(username, host);
	for jid, item in pairs(roster) do
		if jid then
			module:fire_event("roster-item-removed", {
				username = username, jid = jid, item = item, roster = roster, origin = origin,
			});
		else
			for pending_jid in pairs(item.pending) do
				module:fire_event("roster-item-removed", {
					username = username, jid = pending_jid, roster = roster, origin = origin,
				});
			end
		end
	end
end, 300);