Ease the pain of Hadoop log reading (on multiple machines) with Chrome User-Script

README.md

Important!

Remember to run google-chrome like this, for the time of installing this user script:

$ google-chrome --enable-easy-off-store-extension-install

ShowMeTheLogs.user.js

// ==UserScript==                                                                                                                                                                                                                             
// @name        ShowMeTheLogs
// @namespace   hadoop
// @description Show remote jobtracker logs
// @version     0.0.1
// @author      mcl_touk.pl
// @license     (CC) BY-SA-3.0 http://creativecommons.org/licenses/by-sa/3.0/
// @include     http*://localhost:50030/*
// @run-at      document-end
// @noframes
// @grant       GM_deleteValue
// @grant       GM_getValue
// @grant       GM_listValues
// @grant       GM_setValue
// @grant       GM_xmlhttpRequest
// ==/UserScript==


// a function that loads jQuery and calls a callback function when jQuery has finished loading
function addJQuery(callback) {
  var script = document.createElement("script");
  script.setAttribute("src", "//ajax.googleapis.com/ajax/libs/jquery/1.8.1/jquery.min.js");
  script.addEventListener('load', function() {
    var script = document.createElement("script");
    script.textContent = "(" + callback.toString() + ")();";
    document.body.appendChild(script);
  }, false);
  document.body.appendChild(script);
}

// the guts of this userscript
function main() {
  $(document).on("mousedown", "a[href^='http://hadoop']", function(e) {
         e.preventDefault();
         var href = $(this).attr("href");
         var srv_num = href.match(/hadoop(\d)/)[1];
         var port_num = 50060 + parseInt(srv_num, 0);
         var replacePart = href.substring(0, href.indexOf("/", 10));
         href = href.replace(replacePart, "http://localhost:" + port_num);
         console.log("altering link to: " + href);
         window.location = href;
  });

}

// load jQuery and execute the main function
addJQuery(main);

tunnel.sh

ssh -N -L 50062:localhost:50060 root@hadoop2 &
ssh -N -L 50063:localhost:50060 root@hadoop3 &
ssh -N -L 50064:localhost:50060 root@hadoop4 &