File

util/prosodyctl/shell.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 11522:5bd38d9197e1
child 11890:b9aab1962a2b
line wrap: on
line source

local config = require "core.configmanager";
local server = require "net.server";
local st = require "util.stanza";
local path = require "util.paths";
local parse_args = require "util.argparse".parse;
local unpack = table.unpack or _G.unpack;

local have_readline, readline = pcall(require, "readline");

local adminstream = require "util.adminstream";

if have_readline then
	readline.set_readline_name("prosody");
	readline.set_options({
			histfile = path.join(prosody.paths.data, ".shell_history");
			ignoredups = true;
		});
end

local function read_line()
	if have_readline then
		return readline.readline("prosody> ");
	else
		io.write("prosody> ");
		return io.read("*line");
	end
end

local function send_line(client, line)
	client.send(st.stanza("repl-input"):text(line));
end

local function repl(client)
	local line = read_line();
	if not line or line == "quit" or line == "exit" or line == "bye" then
		if not line then
			print("");
		end
		if have_readline then
			readline.save_history();
		end
		os.exit();
	end
	send_line(client, line);
end

local function printbanner()
	print([[
                     ____                \   /     _
                    |  _ \ _ __ ___  ___  _-_   __| |_   _
                    | |_) | '__/ _ \/ __|/ _ \ / _` | | | |
                    |  __/| | | (_) \__ \ |_| | (_| | |_| |
                    |_|   |_|  \___/|___/\___/ \__,_|\__, |
                    A study in simplicity            |___/

]]);
	print("Welcome to the Prosody administration console. For a list of commands, type: help");
	print("You may find more help on using this console in our online documentation at ");
	print("https://prosody.im/doc/console\n");
end

local function start(arg) --luacheck: ignore 212/arg
	local client = adminstream.client();
	local opts, err, where = parse_args(arg);

	if not opts then
		if err == "param-not-found" then
			print("Unknown command-line option: "..tostring(where));
		elseif err == "missing-value" then
			print("Expected a value to follow command-line option: "..where);
		end
		os.exit(1);
	end

	if arg[1] then
		if arg[2] then
			-- prosodyctl shell module reload foo bar.com --> module:reload("foo", "bar.com")
			-- COMPAT Lua 5.1 doesn't have the separator argument to string.rep
			arg[1] = string.format("%s:%s("..string.rep("%q, ", #arg-2):sub(1, -3)..")", unpack(arg));
		end

		client.events.add_handler("connected", function()
			client.send(st.stanza("repl-input"):text(arg[1]));
			return true;
		end, 1);

		local errors = 0; -- TODO This is weird, but works for now.
		client.events.add_handler("received", function(stanza)
			if stanza.name == "repl-output" or stanza.name == "repl-result" then
				if stanza.attr.type == "error" then
					errors = errors + 1;
					io.stderr:write(stanza:get_text(), "\n");
				else
					print(stanza:get_text());
				end
			end
			if stanza.name == "repl-result" then
				os.exit(errors);
			end
			return true;
		end, 1);
	end

	client.events.add_handler("connected", function ()
		if not opts.quiet then
			printbanner();
		end
		repl(client);
	end);

	client.events.add_handler("disconnected", function ()
		print("--- session closed ---");
		os.exit();
	end);

	client.events.add_handler("received", function (stanza)
		if stanza.name == "repl-output" or stanza.name == "repl-result" then
			local result_prefix = stanza.attr.type == "error" and "!" or "|";
			print(result_prefix.." "..stanza:get_text());
		end
		if stanza.name == "repl-result" then
			repl(client);
		end
	end);

	local socket_path = path.resolve_relative_path(prosody.paths.data, opts.socket or config.get("*", "admin_socket") or "prosody.sock");
	local conn = adminstream.connection(socket_path, client.listeners);
	local ok, err = conn:connect();
	if not ok then
		if err == "no unix socket support" then
			print("** LuaSocket unix socket support not available or incompatible, ensure your");
			print("** version is up to date.");
		else
			print("** Unable to connect to server - is it running? Is mod_admin_shell enabled?");
			print("** Connection error: "..err);
		end
		os.exit(1);
	end
	server.loop();
end

return {
	shell = start;
};