gvansanden's blog

Open Source and non profit

I have always thought that Open Source and the non-profit sector where a match made in heaven, but there is too little information structurally flowing to organizations that are already achieving much with limited resources in both time and money.

That is why we (Taurix) in a partnership with the CAW De Kempen (Centrum Algemeen Welzijn) are organizing a free Open Source seminar on december 6.  We will talk about Open Source solutions and how your organization can benefit from them as well as go through case studies from actual users.

Replacing Google reader, part 2

2 Weeks ago, I wrote about replacing Google reader on my blog and promised to get back to you with the results of the 2 alternatives I've been trying out: Owncloud news and Friendica's RSS functionality.

The outcome was decided pretty naturally and it also surprises me a little.  Though Friendica's RSS features is really nice, I ended up using both!

Replacing Google reader

Depending on 'cloud' services is always dangerous.  Case in point, Google is axing 2 services with a large userbase very soon: Jabber (XMPP) better known as GTalk and Google Reader.

And chances would have it these are the only 2 Google services I use.  As I don't have many jabber contacts, it only took 15 minutes to install ejabberd on my groupware server and invite all my contacts again.

A better way to monitor diskspace with Zabbix

Zabbix has a log of built-in support to monitor diskspace on servers.  But I'm not always interested in triggers that fire on a certain amount or percentage of free space defined in  a template.  For some filesystems, it may be perfectly normal to be at 90% usage and remain stable there.

What does interest me more is the amount by which disk usage increases in a short timespan, and Zabbix does have the functionality to cater for this.  For example:

Fixing [Z3005] query failed errors with Zabbix and MySQL

The Zabbix server at my customer failed badly today with a flood of 'unreachable' alerts across multiple locations.  It became clear pretty quickly that the hosts where up and Zabbix was at fault.

With the proxies reported up, I turned to the Zabbix server itself and saw MySQL errors rolling by in the log:

OwnCloud client broken on Ubuntu 12.04

 Just a small heads up for those using OwnCloud and upgraded to precise, version 1.0.1 of their client is broken (exits with csync.vio.main - loading ownclouds plugin failed - /usr/src/packages/BUILD/obj-x86_64-linux-gnu/modules/csync_ownclouds.so: cannot open shared object file: No such file or directory) on 12.04.

OwnCloud will release 1.0.2 soon that fixes this.

Making owncloud work with SSL and a reverse proxy

I set up owncloud yesterday, and it seems to be very nice.

But when I wanted to open it outside my network over SSL, it got stuck in a redirect loop.

Now, I use pound as a reverse proxy to balance requests over several servers and to do SSL termination.  This proved to be the problem, owncloud did not detect that the connection was SSL enabled despite the "X-Forwarded-Proto: https" header added by pound (which fixed similar problems in other webapps).

But luckily, just adding "SetEnv HTTPS on" in the Apache vhost fixed that!

Fighting DNS resolving in Ubuntu 12.04 (server)

I recently installed a DNS sever using Ubuntu 12.04.  The server should serve only my exernal domain, but should use an internal server for it's own name resolution.

Setting dns-nameservers to the correct ip in /etc/network/interfaces did not work on this host (but does on all my non-dns hosts).

After some digging, I found the cause: resolvconf always reverts to nameserver 127.0.0.1 which in turn queries the hosts in dns-nameservers.  Because my host is already a nameserver, 127.0.0.1 points to my bind instance instead of a caching daemon.

Software testing and unexpected failures

 Last week, I released a new version of eLAS, a PHP based web application.  This version included a combination of changes in 2 branches., trunk and an experimental branch that introduced the Mootools javascript framework.  Both branches received significant testing and worked and behaved well.

The merge with the Mootools branch happened very late in the 2.2 cycle because version 3 (which would have gotten this) will not happen for at least another year.

Another Linux Identity article

My latest article titled 'Ubuntu and Gnome 3, from unity to divergence' will be published in the upcoming editon off Linux Identity.

If I find the time. I'm going to put an updated list of my articles up on this site (with links when allowed).

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