File

plugins/mod_disco.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 11204:ae2a11066001
child 11737:59cf555b4698
line wrap: on
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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 get_children = require "core.hostmanager".get_children;
local is_contact_subscribed = require "core.rostermanager".is_contact_subscribed;
local jid_split = require "util.jid".split;
local jid_bare = require "util.jid".bare;
local st = require "util.stanza"
local calculate_hash = require "util.caps".calculate_hash;

local disco_items = module:get_option_array("disco_items", {})
do -- validate disco_items
	for _, item in ipairs(disco_items) do
		local err;
		if type(item) ~= "table" then
			err = "item is not a table";
		elseif type(item[1]) ~= "string" then
			err = "item jid is not a string";
		elseif item[2] and type(item[2]) ~= "string" then
			err = "item name is not a string";
		end
		if err then
			module:log("error", "option disco_items is malformed: %s", err);
			disco_items = {}; -- TODO clean up data instead of removing it?
			break;
		end
	end
end

if module:get_host_type() == "local" then
	module:add_identity("server", "im", module:get_option_string("name", "Prosody")); -- FIXME should be in the non-existing mod_router
end
module:add_feature("http://jabber.org/protocol/disco#info");
module:add_feature("http://jabber.org/protocol/disco#items");

-- Generate and cache disco result and caps hash
local _cached_server_disco_info, _cached_server_caps_feature, _cached_server_caps_hash;
local function build_server_disco_info()
	local query = st.stanza("query", { xmlns = "http://jabber.org/protocol/disco#info" });
	local done = {};
	for _,identity in ipairs(module:get_host_items("identity")) do
		local identity_s = identity.category.."\0"..identity.type;
		if not done[identity_s] then
			query:tag("identity", identity):up();
			done[identity_s] = true;
		end
	end
	for _,feature in ipairs(module:get_host_items("feature")) do
		if not done[feature] then
			query:tag("feature", {var=feature}):up();
			done[feature] = true;
		end
	end
	for _,extension in ipairs(module:get_host_items("extension")) do
		if not done[extension] then
			query:add_child(extension);
			done[extension] = true;
		end
	end
	_cached_server_disco_info = query;
	_cached_server_caps_hash = calculate_hash(query);
	_cached_server_caps_feature = st.stanza("c", {
		xmlns = "http://jabber.org/protocol/caps";
		hash = "sha-1";
		node = "http://prosody.im";
		ver = _cached_server_caps_hash;
	});
end

local function clear_disco_cache()
	_cached_server_disco_info, _cached_server_caps_feature, _cached_server_caps_hash = nil, nil, nil;
end
local function get_server_disco_info()
	if not _cached_server_disco_info then build_server_disco_info(); end
	return _cached_server_disco_info;
end
local function get_server_caps_feature()
	if not _cached_server_caps_feature then build_server_disco_info(); end
	return _cached_server_caps_feature;
end
local function get_server_caps_hash()
	if not _cached_server_caps_hash then build_server_disco_info(); end
	return _cached_server_caps_hash;
end

module:hook("item-added/identity", clear_disco_cache);
module:hook("item-added/feature", clear_disco_cache);
module:hook("item-added/extension", clear_disco_cache);
module:hook("item-removed/identity", clear_disco_cache);
module:hook("item-removed/feature", clear_disco_cache);
module:hook("item-removed/extension", clear_disco_cache);

-- Handle disco requests to the server
module:hook("iq-get/host/http://jabber.org/protocol/disco#info:query", function(event)
	local origin, stanza = event.origin, event.stanza;
	local node = stanza.tags[1].attr.node;
	if node and node ~= "" and node ~= "http://prosody.im#"..get_server_caps_hash() then
		local reply = st.reply(stanza):tag('query', {xmlns='http://jabber.org/protocol/disco#info', node=node});
		local node_event = { origin = origin, stanza = stanza, reply = reply, node = node, exists = false};
		local ret = module:fire_event("host-disco-info-node", node_event);
		if ret ~= nil then return ret; end
		if node_event.exists then
			origin.send(reply);
		else
			origin.send(st.error_reply(stanza, "cancel", "item-not-found", "Node does not exist"));
		end
		return true;
	end
	local reply_query = get_server_disco_info();
	reply_query.attr.node = node;
	local reply = st.reply(stanza):add_child(reply_query);
	origin.send(reply);
	return true;
end);

module:hook("iq-get/host/http://jabber.org/protocol/disco#items:query", function(event)
	local origin, stanza = event.origin, event.stanza;
	local node = stanza.tags[1].attr.node;
	if node and node ~= "" then
		local reply = st.reply(stanza):tag('query', {xmlns='http://jabber.org/protocol/disco#items', node=node});
		local node_event = { origin = origin, stanza = stanza, reply = reply, node = node, exists = false};
		local ret = module:fire_event("host-disco-items-node", node_event);
		if ret ~= nil then return ret; end
		if node_event.exists then
			origin.send(reply);
		else
			origin.send(st.error_reply(stanza, "cancel", "item-not-found", "Node does not exist"));
		end
		return true;
	end
	local reply = st.reply(stanza):query("http://jabber.org/protocol/disco#items");
	local ret = module:fire_event("host-disco-items", { origin = origin, stanza = stanza, reply = reply });
	if ret ~= nil then return ret; end
	for jid, name in pairs(get_children(module.host)) do
		reply:tag("item", {jid = jid, name = name~=true and name or nil}):up();
	end
	for _, item in ipairs(disco_items) do
		reply:tag("item", {jid=item[1], name=item[2]}):up();
	end
	origin.send(reply);
	return true;
end);

-- Handle caps stream feature
module:hook("stream-features", function (event)
	if event.origin.type == "c2s" or event.origin.type == "c2s_unbound" then
		event.features:add_child(get_server_caps_feature());
	end
end);

-- Handle disco requests to user accounts
if module:get_host_type() ~= "local" then	return end -- skip for components
module:hook("iq-get/bare/http://jabber.org/protocol/disco#info:query", function(event)
	local origin, stanza = event.origin, event.stanza;
	local node = stanza.tags[1].attr.node;
	local username = jid_split(stanza.attr.to) or origin.username;
	if not stanza.attr.to or is_contact_subscribed(username, module.host, jid_bare(stanza.attr.from)) then
		if node and node ~= "" then
			local reply = st.reply(stanza):tag('query', {xmlns='http://jabber.org/protocol/disco#info', node=node});
			if not reply.attr.from then reply.attr.from = origin.username.."@"..origin.host; end -- COMPAT To satisfy Psi when querying own account
			local node_event = { origin = origin, stanza = stanza, reply = reply, node = node, exists = false};
			local ret = module:fire_event("account-disco-info-node", node_event);
			if ret ~= nil then return ret; end
			if node_event.exists then
				origin.send(reply);
			else
				origin.send(st.error_reply(stanza, "cancel", "item-not-found", "Node does not exist"));
			end
			return true;
		end
		local reply = st.reply(stanza):tag('query', {xmlns='http://jabber.org/protocol/disco#info'});
		if not reply.attr.from then reply.attr.from = origin.username.."@"..origin.host; end -- COMPAT To satisfy Psi when querying own account
		reply:tag('identity', {category='account', type='registered'}):up();
		module:fire_event("account-disco-info", { origin = origin, reply = reply });
		origin.send(reply);
		return true;
	end
end);

module:hook("iq-get/bare/http://jabber.org/protocol/disco#items:query", function(event)
	local origin, stanza = event.origin, event.stanza;
	local node = stanza.tags[1].attr.node;
	local username = jid_split(stanza.attr.to) or origin.username;
	if not stanza.attr.to or is_contact_subscribed(username, module.host, jid_bare(stanza.attr.from)) then
		if node and node ~= "" then
			local reply = st.reply(stanza):tag('query', {xmlns='http://jabber.org/protocol/disco#items', node=node});
			if not reply.attr.from then reply.attr.from = origin.username.."@"..origin.host; end -- COMPAT To satisfy Psi when querying own account
			local node_event = { origin = origin, stanza = stanza, reply = reply, node = node, exists = false};
			local ret = module:fire_event("account-disco-items-node", node_event);
			if ret ~= nil then return ret; end
			if node_event.exists then
				origin.send(reply);
			else
				origin.send(st.error_reply(stanza, "cancel", "item-not-found", "Node does not exist"));
			end
			return true;
		end
		local reply = st.reply(stanza):tag('query', {xmlns='http://jabber.org/protocol/disco#items'});
		if not reply.attr.from then reply.attr.from = origin.username.."@"..origin.host; end -- COMPAT To satisfy Psi when querying own account
		module:fire_event("account-disco-items", { origin = origin, stanza = stanza, reply = reply });
		origin.send(reply);
		return true;
	end
end);