Monday, August 27, 2012

Fedora 17 - Google Calendar Integration

I have just found this useful post about how to integrate your Google Calendar with Gnome3 Calendar:

I have just tried and it's working great!

( I cannot take a snapshot since the key is not working when the Calendar Overlay is open =P )

Friday, August 24, 2012

Gnome-shell: Show contact list

I have recently switched from RHEL 6 to Fedora 17.

I found myself less productive during the first days and I had the opportunity to agree with people that identify RHEL as a good distribution for enterprises and for people that need to be productive from the beginning, without losing time to adapt to a new environment, even if this could be winning in the long run.

But after this thoughts, that I still believe are true, I started to enjoy the experience of Fedora and Gnome3. I think they are able to satisfy you if you are the kind of person that likes to tweak his system and likes to experiment with it.

 In Fedora 17, one of the biggest area in which you can play with settings is Gnome3.

 Like other people I do believe that some of the decision of the developers have been to radical and that it's not giving out of the box the best experience that it could. A typical example is the fact that they've hidden the shutdown functionalities and that you have to press ALT to see them, something that everyone could agree is not intuitive at all. 

But maybe the idea behind all this radical decisions is that they want to offer a minimal customization, to allow people to change everything that they do not like and to extend the behaviour, a la Firefox.

And talking specifically about this customization, one extension that I've found useful is Empathy Contact List in UserMenu

"Shows an Empathy Contact List launcher in UserMenu"

Something that is really useful in my opinion because otherwise, if you are not using external sw like Pidgin, you have to perform a long set of action to open a message window to one of your contact:

- you have to go in expose mode
- you have to type the name of the contact to open his  panel
- you have to click on the message button

Only after you have done all this you can have a message window.
Like others said, I do not think this is very handy.

The linked extension allows you to have easy access to the contact list. Stop.

But there is a problem. It doesn't work in Fedora 17.

The reason for this is that the code of the extension is trying to execute empathy.desktop, the program integrated in Gnome3 to provide instant messaging functionality, but in Fedora 17, the shortcut file, to execute the program has a slightly different name: fedora-empathy.desktop .

To correct this and fix the problem this is what you have to do:

1) open the source code of the extension here

vi ~/.local/share/gnome-shell/extensions/

2) edit line 19 changing from 'empathy.desktop' to 'fedora-empathy.desktop' and save

3) restart Gnome3 with ALT+F2 followed by the command r

Enjoy your functionality!

The last thing that I'd like to add is the way to access useful information when you try to understand what is happening with an extension that is not behaving properly. There is a log file that gives you lots of useful information.

The approach I suggest you is to execute this command in a shell before starting to use the problematic extension:

tail -f ~/.xsession-errors

In this way you can clearly see what is wrong. This was my log file, that led me to the fix:
    JS ERROR: !!!   Exception in callback for signal: activate
    JS ERROR: !!!     message = '"Shell.AppSystem.get_default().lookup_app("empathy.desktop") is null"'
    JS ERROR: !!!     lineNumber = '19'
    JS ERROR: !!!     fileName = '"/home/pantinor/.local/share/gnome-shell/extensions/"'
    JS ERROR: !!!     stack = '"([object Object],[object _private_Clutter_Event])@/home/pantinor/.local/share/gnome-shell/extensions/

Wednesday, August 22, 2012

Fedora 17 - Spoof Mac Address

I am not sure if this feature it's always been there, but I have recently discovered that Fedora's connection manager allows you to set in the network configuration the desired spoofed mac address.

This is much better than changing it manually with a command like this every time:

sudo ifconfig wlan0 hw ether 00:00:00:00:00:00

If I only had this during Residence Evil period...

Wednesday, August 8, 2012

Git: I wasn't the only one...

To have mixed feelings about the tool and to find it syntax not that clear.

Usually I have problems with syntaxes, It takes me a lot of time to remember the new ones.

Git introduces some keyword. Ok. You know that you have to put some effort to learn the new "verbs".

But just like the inconsistency around all Linux programs that share the same flags and invocation style only rarely, even Git itself show a clear lack of consistency.

Tuesday, August 7, 2012

JVM Performance Tuning Video

I'd like to suggest to anyone that has to deal with Java and JEE development this video of Charlie Hunt, Architect of Performance Engineering at , that give you some explanation and tips about Java memory management mechanism and tools to analyse the related data.

Saturday, August 4, 2012

Gollum Personal Wiki on Openshift

My tabs are begging me to be closed. Even Firefox asks the same.

I have decided that I need to store some of that information somewhere, and that I couldn't just rely on Bookmarks mechanism since I haven't read properly all of those pages and I wouldn't be able to search for the info I would need.

So I have decided I needed a personal wiki.

I wanted something that I could easily push on the web, on Openshift ideally.

I've found out this post:

That suggest the usage of Gollum, a personal Wiki based on Sinatra/Rails.

You do not need to know anything about the underlying technology to deploy and use it.

When you want to use it offline, you just have to un


and the command will execute an in memory webserver that will host locally your wiki. You can start to use it, to read and write what you need and once in a while you just have to push to Openshift git repository to publish all your work online.

The tutorial is a little outdated but it's easy to understand what to change to obtain the result.

If you need any help just drop a line ;)


Fedora needs  python-pygments and python-develfor the code syntax features

Thursday, August 2, 2012

Gnome Extensions Installation Silent Error

I was one of those unlucky ones not able to install Gnome Extensions via the website, on my Fedora 17.

 I've found out I wasn't the only one but we were not a big number and there was not a clear solution to our problem.

 Apparently I have found that is somewhat related to SSL and the time set in you laptop. Yes. I do not why, but it was definitely my case.  

This is the error I was receiving:

JS ERROR: !!!   Exception was: TypeError: info is null
JS ERROR: !!!     lineNumber = '83'JS ERROR: !!!     fileName = '"/usr/share/gnome-shell/js/ui/extensionSystem.js"'
JS ERROR: !!!     stack = '"([object _private_Soup_SessionAsync],[object _private_Soup_Message])@/usr/share/gnome-shell/js/ui/extensionSystem.js:83"'
JS ERROR: !!!     message = '"info is null"'

If you are also unable to join your Google account to your Gnome 3 profile, ( Check with the Google one since the other options were working fine ) you will probably have my same problem.

For some reason that I cannot explain it seems that the clock or the timezone set on you Linux are involved in the problem.

 Try to change them switching form either network updated to something else like New York timezone and repeat the process.
It's enough to check if you can join the Google account.

As soon as you see you are able, also the extension installation is fixed.