Connect to a remote Xvfb server using VNC and a SSH tunnel

Xvfb is an in-memory display server commonly used to execute programs that require a UI in a server which does not have a screen output. Using Xvfb is very convenient when your automated tests are executed in a remote server and orchestrated by a Continuous Integration system.

While having a VNC server running in production instances is not always a great idea due to the potential security flaws, opening port 5900 on this server to allow external connections sounds even worse. This post will guide you through the steps required to access a remote VNC server via an SSH tunnel, without opening any additional ports.

Assuming that Xvfb is already running in your server and the display has been exported to :99, the next step is to install x11vnc:

sudo yum install -y x11vnc

IMPORTANT: Connections to remote x11vnc servers are not password protected by default which leaves your server accessible to potential attackers. Make sure x11vcn is always started with the argument ‘-rfbauth ‘.

We will now establish the tunnel to access the x11vnc server through SSH. This needs to be done in your workstation:

ssh -i [SSH key] -l [username] -L 5900:localhost:5900 [server hostname] ‘x11vnc -display :99 -localhost -rfbauth [VNC server password file]’

You are now ready to access your remote server screen by using a VNC client in your workstation and connecting to localhost:5900

Agile Testing and the challenges for testers

Next February 27th  expo:QA  organizes a new casual afterwork among friends and professionals in Software Testing and QA, in the context of “Agile Testing and challenges for testers”.

Here you can find more details:

We invite you to a talk and snack with our guest Graham Moran, dedicated to the world of software quality and testing for 15 years.

Graham has worked for IBM and AIG between Ireland and Spain. He has a passion for software testing and in particular the training of the same. In recent years he has been working with agile methodologies and is certified as a teacher of ‘ Certified Agile Tester’.

Should testers have a different attitude to work in an agile environment?

This talk describes what the ‘Agile Testing’ is and explores not only the daily challenges that testers face, but the changes in attitude that they adopt.

Graham will conduct a funny Quizz, with some more surprises …

  • Date: 27/02/2014
  • Hour: 19:00 to 21:00.
  • Price: free
  • More information and registration here.

Its defect speaking

Pere Felices just sent me a very funny text about a (software) defect’s life, which I’m sharing here so you can also enjoy it:

I am defect. For some people I am a mild inconvenience and for some I am their worst nightmare, probably a life threatening nightmare. For many years, people like you have treated me as a hunting target and treated me as a non-living entity – without any emotion, say or dreams. Till now, I kept my silence but now I had it enough. TestingGeek has allowed me to tell my story to the world, to tell you truth about me and my feelings.

You call me so many names (And all of them are bad BTW), but do you know anything at all about me? Do you know where I lived before you forced me to live in your code – to be found, discussed, killed, ignored and humiliated?  People tell me so many things, but do you realize reasons for my existent? I know I am not desired, I know I am not welcomed and to be honest, I do not want to come anywhere near your (sometime dirty) code, requirements etc. But you force me to live in your requirements, code, network and so many unimaginable places because of your misunderstandings, lack of knowledge or plain sloppiness some time.

You do not realize, but I pay a great price for your sloppiness and your lack of understanding. I take blame for lost life, money and happiness for many users. Plane is crashed because there was a defect; transaction was not complete because there was a bug and so on. Why don’t you pause, think and say plane was crashed because someone did not do their job properly. I am there not because I love staying in your code, but because someone took short cut, invited me there to be found by someone else. I was invited, ignored and now I am blamed. Where is justice? Unfortunately defects cannot trial humans in their court, but I hope our fate will change.

My life is extremely comfortable till you guys put me in the code. After that, it’s all misery and my life becomes extremely miserable. From that moment onwards, I live my life in anticipation of to be found, broken in pieces, discussed and humiliation. I do not like being here and so always gives you hint of my presence. Sometime, I have power to give strong hints and it becomes impossible for you to ignore me. But sometime, you just do not recognize my hints, you over look what I say in log files, you don’t notice when I create slight flicker or make your system slow. You attribute things like these to something else and leave me there to rot, to get worsen. That doesn’t leave me any option but to gather strength and try harder. Most of the time I succeed and you notice me. Unfortunately I cannot understand your situation so some time by the time you notice me, I might have crashed a plane or ruined millions. So please, practice, observe and understand my hints. I will be very happy if you find me and kill me in such a way that I do not have to come again, but alas it doesn’t happen.

Most of the time, instead of killing me you just change my dress and location. Sometime, you even break me in to pieces and scatter me in your code base. Unfortunately, we do not follow the law of physics so some time when you break me in pieces, every piece could be bigger than the original itself. Even in pieces we communicate with each other, we affect each other and because of this you get confused. Rather than finding all the pieces, you take one piece and kill it or unfortunately break it in even more pieces…and cycle continues.

Buried in your millions of line of code, I wait patiently for my angles called testers who have skills and mandate to discover me. Given the right environment these angles could find most of us. But look, what have you done to my angles? You have converted them from angel to robot so rather than finding me, they are following some steps. If I am lucky, they will find me otherwise my angles will pass by me and ignore me, because someone has given them steps to follow rather than mandate to find me. Will I not feel angry about it? How would you feel if you struggle to survive in a sea and rescue boat follow the route given to them and ignores your plea? Well, that’s how I feel.

Sometime my angels create robot themselves and call it test automation. This can be extremely useful, but only if mandate for them is to find me rather than creating more robots. Unfortunately, for many people mandate is limited to the creation of these robots and they are worse for me. Well, it’s like missing rescue boat in periodic manner, after every check-in, after every few hours or on nightly basis.

I am not selfish and understand that sometime you just can’t kill me, but believe me I will be very happy if you can find me, discuss me meaningfully and take conscious decision to keep me in the code. Because, if you do that I’ll understand that I’ll never ever kill someone because of my presence, I’ll know that I will not ruin your millions. So as long as you have assessed risk associated with me staying in your code, I can live there happily. I just do not want to live there with feeling that I am not wanted here and I can possibly hurt someone.

Please, I do not want to stay in your code or system. I am extremely happy outside, don’t invite me inside. I know some of us are a bit naughty and will come without invitation. For those naughty defects, give our angels mandate to find them in best possible way rather than following steps or creating just robots. I am good at heart and do not want to hurt anyone, so please find me and get me out of your code base.

Remember, I am a defect buried in your code and waiting for you. Please be aware of my presence and keep your eyes open for me.

Waiting to be found – A defect.


ISTQB Advanced (Test Manager) – Mind Map

ISTQB Mind Map

Few weeks ago I was preparing the exam for the ISTQB Advanced Level (Test Manager) certification. This is an oficial certification that proves the candidate skills on several disciplines:

  • Software Testing Basics.
  • Testing Process.
  • Test Management.
  • Reviews.
  • Defect and Incident Management.
  • Standards and Test Improvement Process.
  • Test Tools and Automation.
  • Team Composition.

To prepare myself for the certification I prepared a mind map that includes all the basic concepts from the syllabous. You can download it here:

ISTQB Advanced Level – Test Manager (FreeMind format)

ISTQB Advanced Level – Test Manager (Xmind format)

Let me know if you are interested in a different format.