File

plugins/mod_admin_telnet.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 10859:8de0057b4279
child 12977:74b9e05af71e
line wrap: on
line source

-- 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.
--
-- luacheck: ignore 212/self

module:set_global();
module:depends("admin_shell");

local console_listener = { default_port = 5582; default_mode = "*a"; interface = "127.0.0.1" };

local async = require "util.async";
local st = require "util.stanza";

local def_env = module:shared("admin_shell/env");
local default_env_mt = { __index = def_env };

local function printbanner(session)
	local option = module:get_option_string("console_banner", "full");
	if option == "full" or option == "graphic" then
		session.print [[
                   ____                \   /     _
                    |  _ \ _ __ ___  ___  _-_   __| |_   _
                    | |_) | '__/ _ \/ __|/ _ \ / _` | | | |
                    |  __/| | | (_) \__ \ |_| | (_| | |_| |
                    |_|   |_|  \___/|___/\___/ \__,_|\__, |
                    A study in simplicity            |___/

]]
	end
	if option == "short" or option == "full" then
	session.print("Welcome to the Prosody administration console. For a list of commands, type: help");
	session.print("You may find more help on using this console in our online documentation at ");
	session.print("https://prosody.im/doc/console\n");
	end
	if option ~= "short" and option ~= "full" and option ~= "graphic" then
		session.print(option);
	end
end

console = {};

local runner_callbacks = {};

function runner_callbacks:ready()
	self.data.conn:resume();
end

function runner_callbacks:waiting()
	self.data.conn:pause();
end

function runner_callbacks:error(err)
	module:log("error", "Traceback[telnet]: %s", err);

	self.data.print("Fatal error while running command, it did not complete");
	self.data.print("Error: "..tostring(err));
end


function console:new_session(conn)
	local w = function(s) conn:write(s:gsub("\n", "\r\n")); end;
	local session = { conn = conn;
			send = function (t)
				if st.is_stanza(t) and (t.name == "repl-result" or t.name == "repl-output") then
					t = "| "..t:get_text().."\n";
				end
				w(tostring(t));
			end;
			print = function (...)
				local t = {};
				for i=1,select("#", ...) do
					t[i] = tostring(select(i, ...));
				end
				w("| "..table.concat(t, "\t").."\n");
			end;
			serialize = tostring;
			disconnect = function () conn:close(); end;
			};
	session.env = setmetatable({}, default_env_mt);

	session.thread = async.runner(function (line)
		console:process_line(session, line);
		session.send(string.char(0));
	end, runner_callbacks, session);

	-- Load up environment with helper objects
	for name, t in pairs(def_env) do
		if type(t) == "table" then
			session.env[name] = setmetatable({ session = session }, { __index = t });
		end
	end

	session.env.output:configure();

	return session;
end

function console:process_line(session, line)
	line = line:gsub("\r?\n$", "");
	if line == "bye" or line == "quit" or line == "exit" or line:byte() == 4 then
		session.print("See you!");
		session:disconnect();
		return;
	end
	return module:fire_event("admin/repl-input", { origin = session, stanza = st.stanza("repl-input"):text(line) });
end

local sessions = {};

function module.save()
	return { sessions = sessions }
end

function module.restore(data)
	if data.sessions then
		for conn in pairs(data.sessions) do
			conn:setlistener(console_listener);
			local session = console:new_session(conn);
			sessions[conn] = session;
		end
	end
end

function console_listener.onconnect(conn)
	-- Handle new connection
	local session = console:new_session(conn);
	sessions[conn] = session;
	printbanner(session);
	session.send(string.char(0));
end

function console_listener.onincoming(conn, data)
	local session = sessions[conn];

	local partial = session.partial_data;
	if partial then
		data = partial..data;
	end

	for line in data:gmatch("[^\n]*[\n\004]") do
		if session.closed then return end
		session.thread:run(line);
	end
	session.partial_data = data:match("[^\n]+$");
end

function console_listener.onreadtimeout(conn)
	local session = sessions[conn];
	if session then
		session.send("\0");
		return true;
	end
end

function console_listener.ondisconnect(conn, err) -- luacheck: ignore 212/err
	local session = sessions[conn];
	if session then
		session.disconnect();
		sessions[conn] = nil;
	end
end

function console_listener.ondetach(conn)
	sessions[conn] = nil;
end

module:provides("net", {
	name = "console";
	listener = console_listener;
	default_port = 5582;
	private = true;
});