File

util/statsd.lua @ 11749:83d6d6a70edf

net.http: fail open if surrounding code does not configure TLS Previously, if surrounding code was not configuring the TLS context used default in net.http, it would not validate certificates at all. This is not a security issue with prosody, because prosody updates the context with `verify = "peer"` as well as paths to CA certificates in util.startup.init_http_client. Nevertheless... Let's not leave this pitfall out there in the open.
author Jonas Schäfer <jonas@wielicki.name>
date Sun, 29 Aug 2021 15:04:47 +0200
parent 11523:5f15ab7c6ae5
child 12123:7ba686696250
line wrap: on
line source

local socket = require "socket";
local time = require "util.time".now;
local array = require "util.array";
local t_concat = table.concat;

local new_metric_registry = require "util.openmetrics".new_metric_registry;
local render_histogram_le = require "util.openmetrics".render_histogram_le;

-- BEGIN of Metric implementations

-- Gauges
local gauge_metric_mt = {}
gauge_metric_mt.__index = gauge_metric_mt

local function new_gauge_metric(full_name, impl)
	local metric = {
		_full_name = full_name;
		_impl = impl;
		value = 0;
	}
	setmetatable(metric, gauge_metric_mt)
	return metric
end

function gauge_metric_mt:set(value)
	self.value = value
	self._impl:push_gauge(self._full_name, value)
end

function gauge_metric_mt:add(delta)
	self.value = self.value + delta
	self._impl:push_gauge(self._full_name, self.value)
end

function gauge_metric_mt:reset()
	self.value = 0
	self._impl:push_gauge(self._full_name, 0)
end

function gauge_metric_mt.iter_samples()
	-- statsd backend does not support iteration.
	return function()
		return nil
	end
end

-- Counters
local counter_metric_mt = {}
counter_metric_mt.__index = counter_metric_mt

local function new_counter_metric(full_name, impl)
	local metric = {
		_full_name = full_name,
		_impl = impl,
		value = 0,
	}
	setmetatable(metric, counter_metric_mt)
	return metric
end

function counter_metric_mt:set(value)
	local delta = value - self.value
	self.value = value
	self._impl:push_counter_delta(self._full_name, delta)
end

function counter_metric_mt:add(value)
	self.value = (self.value or 0) + value
	self._impl:push_counter_delta(self._full_name, value)
end

function counter_metric_mt.iter_samples()
	-- statsd backend does not support iteration.
	return function()
		return nil
	end
end

function counter_metric_mt:reset()
	self.value = 0
end

-- Histograms
local histogram_metric_mt = {}
histogram_metric_mt.__index = histogram_metric_mt

local function new_histogram_metric(buckets, full_name, impl)
	-- NOTE: even though the more or less proprietrary dogstatsd has its own
	-- histogram implementation, we push the individual buckets in this statsd
	-- backend for both consistency and compatibility across statsd
	-- implementations.
	local metric = {
		_sum_name = full_name..".sum",
		_count_name = full_name..".count",
		_impl = impl,
		_created = time(),
		_sum = 0,
		_count = 0,
	}
	-- the order of buckets matters unfortunately, so we cannot directly use
	-- the thresholds as table keys
	for i, threshold in ipairs(buckets) do
		local threshold_s = render_histogram_le(threshold)
		metric[i] = {
			threshold = threshold,
			threshold_s = threshold_s,
			count = 0,
			_full_name = full_name..".bucket."..(threshold_s:gsub("%.", "_")),
		}
	end
	setmetatable(metric, histogram_metric_mt)
	return metric
end

function histogram_metric_mt:sample(value)
	-- According to the I-D, values must be part of all buckets
	for i, bucket in pairs(self) do
		if "number" == type(i) and bucket.threshold > value then
			bucket.count = bucket.count + 1
			self._impl:push_counter_delta(bucket._full_name, 1)
		end
	end
	self._sum = self._sum + value
	self._count = self._count + 1
	self._impl:push_gauge(self._sum_name, self._sum)
	self._impl:push_counter_delta(self._count_name, 1)
end

function histogram_metric_mt.iter_samples()
	-- statsd backend does not support iteration.
	return function()
		return nil
	end
end

function histogram_metric_mt:reset()
	self._created = time()
	self._count = 0
	self._sum = 0
	for i, bucket in pairs(self) do
		if "number" == type(i) then
			bucket.count = 0
		end
	end
	self._impl:push_gauge(self._sum_name, self._sum)
end

-- Summaries
local summary_metric_mt = {}
summary_metric_mt.__index = summary_metric_mt

local function new_summary_metric(full_name, impl)
	local metric = {
		_sum_name = full_name..".sum",
		_count_name = full_name..".count",
		_impl = impl,
	}
	setmetatable(metric, summary_metric_mt)
	return metric
end

function summary_metric_mt:sample(value)
	self._impl:push_counter_delta(self._sum_name, value)
	self._impl:push_counter_delta(self._count_name, 1)
end

function summary_metric_mt.iter_samples()
	-- statsd backend does not support iteration.
	return function()
		return nil
	end
end

function summary_metric_mt.reset()
end

-- BEGIN of statsd client implementation

local statsd_mt = {}
statsd_mt.__index = statsd_mt

function statsd_mt:cork()
	self.corked = true
	self.cork_buffer = self.cork_buffer or {}
end

function statsd_mt:uncork()
	self.corked = false
	self:_flush_cork_buffer()
end

function statsd_mt:_flush_cork_buffer()
	local buffer = self.cork_buffer
	for metric_name, value in pairs(buffer) do
		self:_send_gauge(metric_name, value)
		buffer[metric_name] = nil
	end
end

function statsd_mt:push_gauge(metric_name, value)
	if self.corked then
		self.cork_buffer[metric_name] = value
	else
		self:_send_gauge(metric_name, value)
	end
end

function statsd_mt:_send_gauge(metric_name, value)
	self:_send(self.prefix..metric_name..":"..tostring(value).."|g")
end

function statsd_mt:push_counter_delta(metric_name, delta)
	self:_send(self.prefix..metric_name..":"..tostring(delta).."|c")
end

function statsd_mt:_send(s)
	return self.sock:send(s)
end

-- END of statsd client implementation

local function build_metric_name(family_name, labels)
	local parts = array { family_name }
	if labels then
		parts:append(labels)
	end
	return t_concat(parts, "/"):gsub("%.", "_"):gsub("/", ".")
end

local function new(config)
	if not config or not config.statsd_server then
		return nil, "No statsd server specified in the config, please see https://prosody.im/doc/statistics";
	end

	local sock = socket.udp();
	sock:setpeername(config.statsd_server, config.statsd_port or 8125);

	local prefix = (config.prefix or "prosody")..".";

	local impl = {
		metric_registry = nil;
		sock = sock;
		prefix = prefix;
	};
	setmetatable(impl, statsd_mt)

	local backend = {
		gauge = function(family_name, labels)
			return new_gauge_metric(build_metric_name(family_name, labels), impl)
		end;
		counter = function(family_name, labels)
			return new_counter_metric(build_metric_name(family_name, labels), impl)
		end;
		histogram = function(buckets, family_name, labels)
			return new_histogram_metric(buckets, build_metric_name(family_name, labels), impl)
		end;
		summary = function(family_name, labels, extra)
			return new_summary_metric(build_metric_name(family_name, labels), impl, extra)
		end;
	};

	impl.metric_registry = new_metric_registry(backend);

	return impl;
end

return {
	new = new;
}