How to attach a rear rack to this bike?

[seanod]

Hey, could anyone help me in telling me if it would be easy to attach a rear rack to this bike? I don't know much about it and I'm soon going on a ride from Paris to Barcelona. Would I need to buy clips?

 

[dabac]

You'll probably have a better chance of getting a useful answer if you posted a few close-up pics of the bike in question...