thinking sysadmin

HAProxy is load balancer software that allows you to proxy HTTP and TCP connections to a pool of back-end servers; Keepalived – among other uses – allows you to create a redundant pair of HAProxy servers by moving an IP address between HAProxy hosts in an active-passive configuration.
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Following on to my previous post about ack and autojump, one more new-to-me tool that I’ve become quite fond of is f.lux. When you find yourself passing up your dual-core hot-rod workstation for your underpowered netbook solely because the netbook has f.lux installed, take it as a sign that the creators of f.lux are on to something.

From the f.lux website: “f.lux makes your computer screen look like the room you’re in, all the time. When the sun sets, it makes your computer look like your indoor lights. In the morning, it makes things look like sunlight again.” For me, the decrease in eye strain is palpable; at night, picking up a mobile phone or even looking at a TV after using a machine with f.lux installed is painful. (Obviously, if you need accurate color representation, you can’t have f.lux on; thankfully, temporarily disabling it is a breeze.)

There are are Windows, OS X and Linux versions available; installation on Ubuntu is made easy through a PPA. Here’s a little Puppet module for Ubuntu Maverick hosts, if Puppet is your thing:

class flux {

  exec { "add f.lux ppa":
    command => "/usr/bin/apt-add-repository ppa:kilian/f.lux",
    creates => "/etc/apt/sources.list.d/kilian-f_lux-maverick.list",
    notify => Exec["apt-get update"],
  }

  package { "fluxgui":
    ensure => present,
    require => Exec["add f.lux ppa"],
  }

}

A recent answer to a question on Quora – What are some time-saving tips that every Linux user should know? – suggested two tools I’ve found very useful: ack and autojump.
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Drupal is a popular open source CMS reportedly used on tens of thousands of sites ranging from personal blogs to whitehouse.gov; for readers of this blog, it probably requires no further introduction.

Despite its many desirable features and continuing popularity, Drupal is not without its shortcomings, as many readers are also likely aware. Although Drupal has an active and responsive security team, the software has a long track record of requiring frequent security patches – Secunia has seven 2009 advisories for Drupal 6.x listed as of this writing. Although by its nature an apples-to-oranges comparison, this ranks Drupal behind similarly large and complex PHP projects such as WordPress 2.x (5) and Gallery 2.x (0) – and the number for Drupal does not include dozens of additional advisories for Drupal modules. Further, Drupal has struggled and lagged with support for PHP 5.3.x, suggesting to this outside observer that the project is having difficulties maintaining its codebase.

All that being said, I do not personally believe that the above issues rule out using Drupal; the benefits outweigh the shortcomings. So, assuming the question is not whether to deploy Drupal, but how to do so most securely and efficiently, my recommendations from a systems administration perspective are below.
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