mod_http_openmetrics: Serve HTTP from global context
Makes GET /metrics work regardless of the value of the Host header.
This was not possible before 220468f7a103 which added the ability to
have global HTTP modules, which was partly why the per-host part was
kept while the module lived among the community modules.
Another reason was to provide some semblance of security by obscurity by
only loading the module on e.g. a 'localhost' VirtualHost or Component.
The new IP limits obsoletes this.
-- 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;
};
});