view plugins/mod_http_errors.lua @ 13966:e7c52d0b0e0d

util.sql: Add API to start an explicit write transaction This will be used in SQLite3 to BEGIN IMMEDIATE, which attempts to acquire write locks immediately instead of when the first write statement is started. Thus it would fail faster if the write lock is already taken. Normally that should not occur but e.g. prosodyctl could take it. Investigating whether something similar is sensible in PostgreSQL, MySQL is a future task.
author Kim Alvefur <zash@zash.se>
date Mon, 19 Aug 2024 00:06:45 +0200
parents 36d361722889
children
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module:set_global();

local server = require "prosody.net.http.server";
local codes = require "prosody.net.http.codes";
local http_errors = require "prosody.net.http.errors".registry;
local json = require "prosody.util.json";
local new_short_id = require "prosody.util.id".short;
local xml_escape = require "prosody.util.stanza".xml_escape;
local render = require "prosody.util.interpolation".new("%b{}", xml_escape);


local show_private = module:get_option_boolean("http_errors_detailed", false);
local always_serve = module:get_option_boolean("http_errors_always_show", true);
local default_message = { module:get_option_string("http_errors_default_message", "That's all I know.") };
local default_messages = {
	[400] = { "What kind of request do you call that??" };
	[403] = { "You're not allowed to do that." };
	[404] = { "Whatever you were looking for is not here. %";
		"Where did you put it?", "It's behind you.", "Keep looking." };
	[500] = { "% Check your error log for more info.";
		"Gremlins.", "It broke.", "Don't look at me." };
	["/"] = {
		"A study in simplicity.";
		"Better catch it!";
		"Don't just stand there, go after it!";
		"Well, say something, before it runs too far!";
		"Welcome to the world of XMPP!";
		"You can do anything in XMPP!"; -- "The only limit is XML.";
		"You can do anything with Prosody!"; -- the only limit is memory?
	};
};

local messages = setmetatable(module:get_option("http_errors_messages", {}), { __index = default_messages });

local html = [[
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>{title}</title>
<style>
:root{color-scheme:light dark}
body{margin-top:14%;text-align:center;font-family:sans-serif}
h1{font-size:xx-large}
p{font-size:x-large}
p.warning>span{font-size:large;background-color:yellow}
p.extra{font-size:large;font-family:courier}
@media(prefers-color-scheme:dark){
p.warning>span{background-color:inherit;color:yellow}
}
</style>
</head>
<body>
<h1>{icon?{icon_raw!?}} {title}</h1>
<p>{message}</p>
{warning&<p class="warning"><span>&#9888; {warning?} &#9888;</span></p>}
{extra&<p class="extra">{extra?}</p>}
</body>
</html>
]];

local function get_page(code, extra)
	local message = messages[code];
	if always_serve or message then
		message = message or default_message;
		return render(html, {
			title = rawget(codes, code) or ("Code "..tostring(code));
			message = message[1]:gsub("%%", function ()
				return message[math.random(2, math.max(#message,2))];
			end);
			extra = extra;
		});
	end
end

-- Main error page handler
module:hook_object_event(server, "http-error", function (event)
	if event.response then
		event.response.headers.content_type = "text/html; charset=utf-8";
	end
	return get_page(event.code, (show_private and event.private_message) or event.message or (event.error and event.error.text));
end);

-- Return error object as JSON if that's what requester prefers
module:hook_object_event(server, "http-error", function (event)
	if event.request and (event.request.headers.accept or ""):match("^application/json") then
		event.response.headers.content_type = "application/json";
		local error = event.request and event.error;
		if not error then
			error = http_errors[event.response.status_code];
		end
		local extra = error.extra;
		return json.encode({
			instance_id = error.instance_id or new_short_id();
			type = error.type;
			condition = error.condition;
			text = error.text or (show_private and event.private_message) or event.message;
			namespace = extra and extra.namespace;
			subcondition = extra and extra.condition;
			source = error.source or "mod_http_errors";
		});
	end
end, 0.1);

-- Way to use the template for other things so to give a consistent appearance
module:hook("http-message", function (event)
	if event.response then
		event.response.headers.content_type = "text/html; charset=utf-8";
	end
	return render(html, event);
end, -1);

local icon = [[
<svg xmlns="http://www.w3.org/2000/svg" height="0.7em" viewBox="0 0 480 480" width="0.7em">
<rect fill="#6197df" height="220" rx="60" ry="60" width="220" x="10" y="10"></rect>
<rect fill="#f29b00" height="220" rx="60" ry="60" width="220" x="10" y="240"></rect>
<rect fill="#f29b00" height="220" rx="60" ry="60" width="220" x="240" y="10"></rect>
<rect fill="#6197df" height="220" rx="60" ry="60" width="220" x="240" y="240"></rect>
</svg>
]];

-- Something nicer shown instead of 404 at the root path, if nothing else handles this path
module:hook_object_event(server, "http-error", function (event)
	local request, response = event.request, event.response;
	if request and response and request.path == "/" and response.status_code == 404 then
		response.status_code = 200;
		response.headers.content_type = "text/html; charset=utf-8";
		local message = messages["/"];
		return render(html, {
				icon_raw = icon,
				title = "Prosody is running!";
				message = message[math.random(#message)];
			});
	end
end, 1);