plugins/mod_http_errors.lua

   1 module:set_global();
   2 module:depends("http");
   3
   4 local server = require "net.http.server";
   5 local codes = require "net.http.codes";
   6 local termcolours = require "util.termcolours";
   7
   8 local show_private = module:get_option_boolean("http_errors_detailed", false);
   9 local always_serve = module:get_option_boolean("http_errors_always_show", true);
  10 local default_message = { module:get_option_string("http_errors_default_message", "That's all I know.") };
  11 local default_messages = {
  12         [400] = { "What kind of request do you call that??" };
  13         [403] = { "You're not allowed to do that." };
  14         [404] = { "Whatever you were looking for is not here. %";
  15                 "Where did you put it?", "It's behind you.", "Keep looking." };
  16         [500] = { "% Check your error log for more info.";
  17                 "Gremlins.", "It broke.", "Don't look at me." };
  18 };
  19
  20 local messages = setmetatable(module:get_option("http_errors_messages", {}), { __index = default_messages });
  21
  22 local html = [[
  23 <!DOCTYPE html>
  24 <html>
  25 <head>
  26         <meta charset="utf-8">
  27         <style>
  28                 body{
  29                         margin-top:14%;
  30                         text-align:center;
  31                         background-color:#F8F8F8;
  32                         font-family:sans-serif;
  33                 }
  34                 h1{
  35                         font-size:xx-large;
  36                 }
  37                 p{
  38                         font-size:x-large;
  39                 }
  40                 p+p { font-size: large; font-family: courier }
  41         </style>
  42 </head>
  43 <body>
  44         <h1>$title</h1>
  45         <p>$message</p>
  46         <p>$extra</p>
  47 </body>
  48 </html>]];
  49 html = html:gsub("%s%s+", "");
  50
  51 local entities = {
  52         ["<"] = "&lt;", [">"] = "&gt;", ["&"] = "&amp;",
  53         ["'"] = "&apos;", ["\""] = "&quot;", ["\n"] = "<br/>",
  54 };
  55
  56 local function tohtml(plain)
  57         return (plain:gsub("[<>&'\"\n]", entities));
  58
  59 end
  60
  61 local function get_page(code, extra)
  62         local message = messages[code];
  63         if always_serve or message then
  64                 message = message or default_message;
  65                 return (html:gsub("$(%a+)", {
  66                         title = rawget(codes, code) or ("Code "..tostring(code));
  67                         message = message[1]:gsub("%%", function ()
  68                                 return message[math.random(2, math.max(#message,2))];
  69                         end);
  70                         extra = tohtml(extra or "");
  71                 }));
  72         end
  73 end
  74
  75 module:hook_object_event(server, "http-error", function (event)
  76         return get_page(event.code, (show_private and event.private_message) or event.message);
  77 end);