So, I've been working with Chef quite a bit, lately. Every once in a while, I'll bootstrap a new node and it fails with this:
Net::HTTPServerException: 412 "Precondition Failed"
Every single time this has happened to me, I've had stop and scratch my head. Why can't I remember what causes this!? Well, in my case it's usually a misspelled cookbook or recipe name. For example, I might have a role that looks something like this:
name "sample-server"
description "sample apache server"
run_list "role[apache::default]"
Can you spot the problem? The opscode cookbook for apache is named apache2!
name "sample-server"
description "sample apache server"
run_list "role[apache2::default]"
So, one complaint that I have about chef is that Net::HTTPServerException: 412 "Precondition Failed" should probably say something like Net::HTTPServerException: 412 "Couldn't find cookbook 'apache'". Oh well... C'est la vie