Case study: Howard Johnson Hotel – how NOT to sell your Wifi

nessus-1Few things are more annoying than hotels, who think they need to earn some extra cash by charging people for wireless internet. Given the low to nonexistent cost of providing the service, they should also charge for warm water or fresh air, when following the same logic.

In the case of a local Howard-Johnson (HoJo) hotel, the wifi's paywall was so badly implemented, it actually posed a threat to the rest of the hotel. Below, I will describe 4 options, anyone can use to get free internet at this particular hotel. Continue reading

Buggy Mac OSX 10.9 Mavericks update

A word of warning: Updating from Mountain lion to Mavericks is by far the most buggy process I have ever seen from Apple. At times the installer quit in the middle, My time machine volume was not recognized, network settings are lost, ...

Make sure you have multiple backups and plan some downtime. On the plus-side Homebrew and my Python-packages all survived. Just make sure you use pip with a virtualenv or the --user option.

Good luck.

Attack from below – Oracle vs the rest

Threats rarely come from above, but most of the time from below. Small and flexible companies start with niches and keep improving their performance, until they become a threat to the established player. In this case we see the S-curve model playing out against Oracle.

These migrations indicate that after years of development, many open source or low-cost databases have now attained performance that is either roughly equivalent to parts of Oracle, such as Postgres, or have developed capabilities that while irrelevant to much of the database market, are far in advance of any technology operated by the Red Borg, such as MongoDB or Riak or Cassandra.

via Hungry termites nibbling at Oracle's foundation

Personally I'm a fan of MongoDB and Redis. I also tried CouchDB, but didn't find it very active.

OwnCloud Update

OC has been updated to version 5. Some of the shared files are not compatible between major versions. If you are missing any shares, just recreate them.

Rest should be ok. If you have any issues, let me know.

Happy New Year 2013!

Good luck in 2013 to everyone. I hope that it will be quieter than 2012 and we get some time to consolidate some of the big trends that started in 2012. My favourite ones are the Raspberry Pi and ownCloud.

I also applied the latest 3.5 update to WordPress. This brought some changes in media management. So in case you miss some pictures, just check for the correct paths in your posts. Generally most stuff should still work.

OwnCloud 4.5 released

This morning version 4.5 of the excellent owncloud package was released. This is excellent competition to all those Apples and Googles who fight to take control of your personal data. Finally there is a decent solution to host all of this yourself.

Calendar, as well as sharing it works flawless without problems. For addressbooks, there seems to be a flaw in Mac OSX, which prevents the addressbook app to see more than one of them. It just picks the first it sees. If someone shares an addressbook with you, it can even cover up your own contacts. This is quite annoying and I recommend not using this feature for now. Hopefully a workaround is found soon.

Rest should work fine. You can install all settings via profiles as usually. Old installations will continue to work as well. In case you experience any problems, just reinstall your configuration profile and let it sync again.

Scan image via SSH

We have an ancient Brother scan+print combination in our apartment. Cheap and reliable. Printing works well over CUPS, also from iPads with Airprint. My only issue was scanning. It works well with SANE, which also works via your network. Only problem is that the packages provided by Mattias Ellert on his website are a bit outdated and don't always work with the latest Mac OSX. So here is a quick trick to scan on a remote machine without the trouble of moving the file later:

[cc lang="bash" width="100%" noborder="1" theme="dawn"] ssh cyrus@gaia.local "sudo scanimage --resolution 400 --format=tiff" | convert tiff:- -quality 90 -quiet `date "+%Y-%m-%d_%H-%M-%S"`.jpg  [/cc]

Basically this command pipes the image over SSH and hands it over to the local convert for compression. Neat and elegant. 🙂

XBian – Raspberry Pi-based distro for running XBMC

Here just some upaid advertising for a nice armhf-based XBMC distro, I discovered some time ago. If you just want to use your RPI for watching movies and TV-shows, this is definitely for you. It auto-starts XBMC, mounts USB-drives and lets you connect to NFS and SMB as well. They only thing you might want to do is keep your XMBC-user folder on a different drive, so you can easily switch versions and always have a backup.


Raspberry Pi for CCTV using motion

I wrote about doing CCTV with zoneminder before, but realized that this might be overkill for many people. If you use less than 4 cameras, you can use the motion package. It works nicely with the Logitech webcam, I connected to my Raspberry.

Raspberry Pi running motion over a web browser
Figure 1: Raspberry Pi running motion over a web browser.

The camera worked out of the box except that saturation, brightness, etc was way off. You can configure it with the v4l2-utils package. Once you have verified that the picture is OK by using uvccapture, you should be ready to install motion. For my USB webcam, motion worked out of the box. No settings needed at all. For finetuning, I changed the framerate in /etc/motion/motion.conf to 25. Even at that rate, load stayed at 0.00 with abotu 20% CPU usage. Maybe the GPU is doing the bulk of the image processing work.

Continue reading

Discontinued: DaviCal

The outdated and little-used calDAV and cardDAV service at has been discontinued in favor of the more modern ownCloud. Users are encouraged to move their data to the new platform. The OTA-profiles are already adapted to the new service. The service will probably be turned off on 1 Nov 2012 or after ownCloud gets better calendar sharing.

Using Raspberry Pi for CCTV with Zoneminder

Note: zoneminder might be overkill for many people. If you have less than 4 cameras, also read my article about doing CCTV with the motion package.

One of the first uses, for the Raspberry Pi, I thought of was qick-and-dirty CCTV. This could be useful for scenarios, like remote construction sites, senior citizens, holiday homes, etc.

The only gear needed is a Raspberry Pi, a USB webcam and internet access through a router. The webcam could also be a network camera or a network digitizer. That way you have more flexibility with your location. The router could be substituted for a 3G data stick. If you have a spare TV, you could also use it for viewing those cameras. Continue reading

Access your Raspberry-Pi through any Browser with VNC

The other day I set up Ubuntu in a virtual Machine to do some preparation work before deploying a similar setup in Amazon's EC2. This basically included programming some Java in Eclipse. When I had to show some stuff to a colleage, I found a quick trick to share a screen remotely on Lifehacker.

This also works well, if you don't have a screen for your Raspberry or want to access some work files, while on the road. First you need to install the necessary packages Continue reading

Use Raspberry Pi to Print From Your iPad or iPhone

Yesterday, I described how you can use your Raspberry Pi to download and access torrents. Today my parents asked me to help them set up printing via their iPads. They have a rather old HP Deskjet 5940 printer with a simple USB interface.

Raspberry Pi print server

First you need to install CUPS (common unix printing system) for printer access. In my case the required printer drivers were installed automatically (hplip). If you are using a different printer you might have to check which packages you need.

Continue reading