When using Ubuntu as a KVM host and UFW for your firewalling, the KVM client can experience a problem with connecting to the outside world. This is related to the bug #573461 in launchpad. The sollution is to edit the /etc/ufw/before.rules You will need to add this line before the COMMIT portion of the file, I have [...]

The scenario: High-availability setup with 2 HAProxy/Keepalived load-balancers on a dualstack IPv4/IPv6 setup. The problem: HAProxy won’t start (cannot bind socket) because the virtual IPv6 address is not assigned. With IPv4, you can set the sysctl parameter: net.ipv4.ip_nonlocal_bind=1 The solution: configure the floating/virtual IPv6 address on the LOOPBACK interface [root@kvm-lb02 haproxy]# /sbin/ip -6 addr add [...]

When you run a webserver behind a reverse proxy or HTTP accelerator like Squid or Varnish, or as I do HAProxy, the webserver access logs will display the IP of the proxy (generally the proxy IP) instead of the end user’s IP. This breaks any kind of tracking or reporting, but it also creates a security hole. An example [...]

In order to run TweetDeck on your desktop, you must have Adobe AIR installed. Before, you can install this application easily. However, Adobe has discontinued supporting AIR for Linux. Fortunately, they still provide access to the last release of AIR for Linux. First step, download the last build of AIR for Linux here. After downloading, [...]

When using KVM on your server, it is nice to have the option that you can reach your VM’s console from the host server (even when the networking in the VM is not functioning). To be able to do this, we need to follow these steps: Edit the VM’s settings: virsh edit vm01 In the [...]

I wanted to display my Nagios reports on my website and started looking for a sollution. Obviously, there where some perl options, but as my website is written in php, that did not fit my needs. Therefore, here the how to in php

With the new WordPress version, the WordPress core developers decided that the admin bar is an essential part of the Admin section (from what I understand). Personal, I don’t find much use for it. To me it’s just a ugly bar at the top of the page which fucks up the layout of my website [...]

If you’re using SVN to control your web application, like I do, your certainly need to deny access to .svn sub-directories. research

As you might have seen, I am kinda happy with the fail2ban system as it’s a very nice tool to keep unwanted losers outside. But I wanted to see how fail2ban is doing, without the need to check my mail constantly. As my servers use munin for graphing stats, the most obvious idea was to [...]

This week during a interview, someone asked me if I knew IPv6 and how long I have been using it. My awnser kind of shocked the person who asked the question, because I have been using IPv6 for ages now.. Today I decided to lookup the old data of my first IPv6 connection.. september 2003.. [...]