File

util/http.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 (2021-04-18)
parent 9785:ff88b03c343f
child 13124:f15e23840780
line wrap: on
line source
-- Prosody IM
-- Copyright (C) 2013 Florian Zeitz
--
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--

local format, char = string.format, string.char;
local pairs, ipairs = pairs, ipairs;
local t_insert, t_concat = table.insert, table.concat;

local url_codes = {};
for i = 0, 255 do
	local c = char(i);
	local u = format("%%%02x", i);
	url_codes[c] = u;
	url_codes[u] = c;
	url_codes[u:upper()] = c;
end
local function urlencode(s)
	return s and (s:gsub("[^a-zA-Z0-9.~_-]", url_codes));
end
local function urldecode(s)
	return s and (s:gsub("%%%x%x", url_codes));
end

local function _formencodepart(s)
	return s and (urlencode(s):gsub("%%20", "+"));
end

local function formencode(form)
	local result = {};
	if form[1] then -- Array of ordered { name, value }
		for _, field in ipairs(form) do
			t_insert(result, _formencodepart(field.name).."=".._formencodepart(field.value));
		end
	else -- Unordered map of name -> value
		for name, value in pairs(form) do
			t_insert(result, _formencodepart(name).."=".._formencodepart(value));
		end
	end
	return t_concat(result, "&");
end

local function formdecode(s)
	if not s:match("=") then return urldecode(s); end
	local r = {};
	for k, v in s:gmatch("([^=&]*)=([^&]*)") do
		k, v = k:gsub("%+", "%%20"), v:gsub("%+", "%%20");
		k, v = urldecode(k), urldecode(v);
		t_insert(r, { name = k, value = v });
		r[k] = v;
	end
	return r;
end

local function contains_token(field, token)
	field = ","..field:gsub("[ \t]", ""):lower()..",";
	return field:find(","..token:lower()..",", 1, true) ~= nil;
end

local function normalize_path(path, is_dir)
	if is_dir then
		if path:sub(-1,-1) ~= "/" then path = path.."/"; end
	else
		if path:sub(-1,-1) == "/" then path = path:sub(1, -2); end
	end
	if path:sub(1,1) ~= "/" then path = "/"..path; end
	return path;
end

return {
	urlencode = urlencode, urldecode = urldecode;
	formencode = formencode, formdecode = formdecode;
	contains_token = contains_token;
	normalize_path = normalize_path;
};