varnishtest documentation

[varnish at syrota.com]

Quoting Poul-Henning Kamp <phk at phk.freebsd.dk>:

> I trust it you have spotted the 347 test-descriptions in the
> source tree ?   They're probably the main documentation for it.

Yeah, saw them, and that was one of the main sources on how to use the  
features. Although some of the arguments I could never find in those  
test cases

> The main reason varnishtest has not been documented, is that it
> we weren't sure if anybody would ever bother read the documentation
> if we wrote it, and given that we have more ideas for things to
> do than time to do them it ended up somewhat low in the pile.

Yeah, judging by how hard it is to come by any discussion of it, it is  
quite rarely used feature, so the priority is understandable :)

> A quick top-level architectural overview:

Thanks for the overview. That helps with a few things that I had not  
understood before. I'll probably put together a pull request for this  
architecture overview (I'll try to fit it into the existing  
varnishtest page) and vtc commands. And we can go from there, if  
anyone will be interested.

Best regards,
Sergey Syrota