Today, Varnish Software released The Varnish Book, an effort they’ve been working at since 2008. It’s available under a CC license as a PDF download and online reference from their website.
Even though the official description touts it as primarily training material, the exercises are supplementary to detailed descriptions and example code, making it an ideal reference point for anyone using Varnish. Topics covered in detail include the VCL language, tuning the daemons and ESI (edge-side includes). There’s less detail on the auxiliary applications like varnishlog and varnishhist, which are defined as being outside the scope of the book. More advanced, slightly dangerous topics like inline C in VCL, are omitted.
In this book, I finally have the diagram I’ve always wished for:
The Varnish Book is a welcome addition to the existing documentation. It’s also great material for internal training (commercial use is prohibited under the terms of the license). Grab it now from Varnish Software.