Blogs

Yesterday I attended the first meet up of the Dutch Puppet User Group and I gave a talk about how to start with Puppet.

It was called: Puppet deployment, an introduction and the PDF slideshow can be viewed or downloaded from speakerdeck.

If you have any comment, please send me an email.

Today I received an email from Chris Hackenschmidt with a patch for a category cloud for my We-Blog program.

Of course I have implemented that and you can see it in action on the right.

So, a new version of We-Blog is out, currently still 0.9, with a big Thank You to Chris.

Download it and enjoy.

John Macfarlane released a new version of Pandoc that has a lot of new enhancements. A lot of things have changed in the Markdown input types and it’s now compatible with PHP Markdown. This is very nice, because a lot of implementations use the extensions defined by PHP Markdown.

I downloaded the dmg file to install it on my MacBook Pro and it works like a charm.

So, I decided to install it on my new CentOS 6 server to build documents there. Well, I was in for a nice surprise.

Today a colleague asked me to sync some files to a server that is not listening on SSH port 22.

I normally create a configuration entry in my ~/.ssh/config file, like

and then command

But this time I didn’t want to create the entry in my SSH configuration, because I need this trick in a script. So I started to read the rsync manpage and after some experimenting I found

Playing with Ansible I did get the idea to make a nice welcome message when you log in to a server. This message needs to be placed in a file, which is configured in /etc/ssh/sshd_config with the banner option. I call this file /etc/issue.

Of course I want to deploy this file with Ansible, so I first defined an entry in the hosts file. This looks like this:

Hendrik Jan Thomassen not only sent me the tail of Haggis hunting but also a nice ancient poem as an ode to Haggis.

Here it is:

Most people are familiar with my love of Scotland, single malt and (of course) haggis. But most people do not have a clue what haggis is and when you tell them, they walk out in disgust.

But a colleague of mine found out that haggis is just an animal that can be hunted in the Scottish Highlands.

This is how it’s done:

I often have to increase the size of a virtual disk on a virtual machine. But I always seem to forget how to do it. I guess I have done it over a 100 times and I cannot remember exactly how I did it. So this blog entry is to help people on how to do this and as a reminder to myself.

This example is done on a virtual machine with CentOS 6, but it can be done on every Linux. And in the fdisk examples I have left out some of the not to interesting lines.

After upgrading my MySQL database server from version 5.0.95 to 5.1.61 I suddenly got these errors in the backup logging.

Hmm, no idea what has happened. I hope I didn’t do something stupid.

Today the classic, and old, Common Desktop Environment (a.k.a. CDE) was released into the Open Source world.

You can get the very alpha version at SourceForge.

I haven’t been able to get a running version by now, but I keep trying.

Good job, guys.

Working with git a lot I decided I needed some git status in my prompt.

I searched the web and some solutions where almost what I wanted and this one by Sebastian Celis came very close.

But it didn’t work with my version of zsh, because that didn’t seem to understand the =~ operator.

I also think Sebastian makes things over complicated and so I changed some things aroud.

This is what I came up with:

When installing a minimal CentOS 6 system, minimal really, really means minimal. After a reboot the network interfaces do not start, so network connectivity is non existing.

Looking into that I noticed that the file /etc/sysconfig/network-scripts/ifcfg-eth0 contained

The lines that mess things up are NM_CONTROLLED=yes meaning the interfaces are managed with NetworkManager, which isn’t actually installed as part of a minimal install. You want a minimal install, you get a minimal install. And ONBOOT=no, meaning do not start the interface on boot. How stupid is that!

Today I released version 0.8 of We-Blog.

I created a Google project and a Google discussion group.

Version 0.8 is now the stable branch and 0.9 the development branch.

It often happens that I get into a situation where I need to know key codes of pressed keys. On my Mac that’s simple. Just use the Key Codes by Many Tricks.

But on Linux I constantly was trying to find out which key produced what.

So I ended up writing a program for that. I started of in the shell, but that ended up being rather tricky and unnecessary complicated. So I redid the whole thing in C.

I was trying to burn a folder with a VIDEO_TS directory onto a DVD. But in a way that it will start in a normal DVD player as well as starting automagically. And this all had to be done on Apple’s OSX.

I googled a little and tried some things and this is what I can up with:

Make sure that /path/to/VIDEO_TS/parent/folder is the path to the folder containing the VIDEO_TS folder, not the VIDEO_TS folder itself.`

I’m registered as a Computable expert and as required I do have a profile page on their website.

And now I get this (partially in Dutch):

Today I’ve posted a new version of the header program.

Nothing really fancy happened, just added support for zonefiles, in this case the Bind ones.

It’s available at the usual places.

I’m creating a Puppet Starter Kit with some standard manifests included and a complete set of documentation. All documentation should be written in Markdown and will be served by Markdoc. But I want to generate all Markdown files from the Puppet manifests, so I only need to document the manifest file. Generating the Markdown is not that difficult, except that I kept ending up with empty lines at the top of the manifest code and I wanted to get rid of those. Of course this should be done with sed, because the whole generation process is written in bash. When playing around with sed I found _~ sed `/./,$!d' filename _~ which, I think, is genius in it’s simplicity. After you find something, do not remove. Life in UNIX and Linux is nice!

When working with Puppet and a VCS (like git and SVN) it’s nice to have a simple way of updating the Puppet tree.

My tree is always in /etc/puppet and owned by user and group puppet. User puppet is allowed to checkout the complete tree from git or subversion.

I have created two one-liners to update the complete tree and make sure all rights are still correct.

update_svn _~ \{.bash} #!/bin/bash # update_svn su - puppet -c `cd /etc/puppet; svn up; cd doc; ../bin/gendoc' _~

Today is world IPv6 day. So come on you all and make your things IPv6 aware and working. If Google can do it, you surely can as well ;-).

This site is available through IPv6 a long time already and can be reached at

Join, and that’s an order!

I’m using Pygments for quite some time now and I just noticed there was a new version available (1.5). I installed that and I was wondering if there would be a lexer included for Puppet. Well, it wasn’t, but a short Google action directed me to the Pygments lexer for the Puppet DSL.

Of course my old CentOS 5 system with Python 2.6 doesn’t want to install this, so I hacked the Puppet lexer into Pygments.

To present PDF slides on Linux I use pdfPres. But when I want to use this on OS X Lion, this doesn’t work. So I created an OS X Lion package for pdfPres.

This is only tested on OS X Lion and it does require XQuartz.

Please, download the pdfPres package and test it.

This week I was asked to setup a system with a single MySQL master server and a couple of slave servers. I have done that before, so there is no problem. The problem is that I do not do that on a daily basis, so I need to check the commands every time I set it up. So, as a note to myself I describe how to setup a single MySQL master with multiple slaves.

Since a couple of days I’m also on Twitter.

I tried to avoid it for a while, but I wanted to follow some people, so it was about time I started to Twitter as well.

As you can imagine, no graphics for me. It turned out that wasn’t as easy as I hoped. Some of the Twitter command line tools did not work or where that old that they even didn’t compile.

In the last couple of weeks I’ve been teaching a course for shell-script starters.

When I was explaining $@ and $* and the difference between these two a student asked me:

WTF?

Unfortunately I couldn’t answer the question, because I don’t have any idea what he’s talking about.