plugins/mod_http_openmetrics.lua
author Matthew Wild <mwild1@gmail.com>
Tue, 11 Oct 2022 11:37:55 +0100
changeset 12767 d26eefe98d09
parent 11946 b4f77a7bf8ab
child 12981 74b9e05af71e
permissions -rw-r--r--
util.dbuffer: Add efficient shortcuts for discard() in certain cases If the buffer is already empty, nothing to do. If we're throwing away the whole buffer, we can just empty it and avoid read_chunk() (which in turn may collapse()). These shortcuts are much more efficient.

-- Export statistics in OpenMetrics format
--
-- Copyright (C) 2014 Daurnimator
-- Copyright (C) 2018 Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>
-- Copyright (C) 2021 Jonas Schäfer <jonas@zombofant.net>
--
-- This module is MIT/X11 licensed.

module:set_global();

local statsman = require "core.statsmanager";
local ip = require "util.ip";

local get_metric_registry = statsman.get_metric_registry;
local collect = statsman.collect;

local get_metrics;

local permitted_ips = module:get_option_set("openmetrics_allow_ips", { "::1", "127.0.0.1" });
local permitted_cidr = module:get_option_string("openmetrics_allow_cidr");

local function is_permitted(request)
	local ip_raw = request.ip;
	if permitted_ips:contains(ip_raw) or
	   (permitted_cidr and ip.match(ip.new_ip(ip_raw), ip.parse_cidr(permitted_cidr))) then
		return true;
	end
	return false;
end

function get_metrics(event)
	if not is_permitted(event.request) then
		return 403; -- Forbidden
	end

	local response = event.response;
	response.headers.content_type = "application/openmetrics-text; version=0.0.4";

	if collect then
		-- Ensure to get up-to-date samples when running in manual mode
		collect()
	end

	local registry = get_metric_registry()
	if registry == nil then
		response.headers.content_type = "text/plain; charset=utf-8"
		response.status_code = 404
		return "No statistics provider configured\n"
	end

	return registry:render();
end

module:depends "http";
module:provides("http", {
	default_path = "metrics";
	route = {
		GET = get_metrics;
	};
});