From the very first paragraph of the README:

> This repo contains the PDF book The Cyber Plumber's Handbook - The definitive guide to Secure Shell (SSH) tunneling, port redirection, and bending traffic like a boss. The book was first published in October 2018 for purchase, but now I'm providing it for FREE to anyone interested in learning more about the magic of SSH tunnels and port redirection.

The license is a CC license. https://github.com/opsdisk/the_cyber_plumbers_handbook/blob/...

He is right about it not being open [1], but since I don't see anything at the repo that claims it is open I don't see anything wrong here.

Books aren't computer programs, and most people even in the free/open source software world seem to be OK with book licenses being less open than software licenses. If the book is available in a good digital edition and can be freely copied and distributed they usually consider that good enough.

[1] It is a CC license, but it is not one of the 5 CC licenses that meets the "Open Definition" for data and content of the Open Knowledge Foundation [2].

[2] https://opendefinition.org/licenses/

> Your purchase includes a PDF lab guide with 45+ exercises and 28 days of interactive access to a real live lab to practice SSH tunneling and port redirection techniques!

You consider a book that’s free spam just because it has a paid companion? Jeeze, HN is tough.

OP, this is really cool. Thanks for sharing.

Where does it pretend anything? The license in use can be found here: https://github.com/opsdisk/the_cyber_plumbers_handbook/blob/...

I think you are confusing two books. The author has a book on SSH tunneling and a lab guide for an interactive lab they offer about SSH tunneling.

The first is free, the second is a commercial product.

I am not selling anything and the author of this book is giving it away for free. The lab guide and access to the lab servers cost something.

OP, for what it's worth, this is a great resource regardless of license nitpicking. Thanks for publishing this repo.