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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 |
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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);