isabella232 / batali-infuse

Batali infusion for chef-client

Batali Infuse

Add an infusion of Batali to chef-client!

Infusing Batali

This gem infuses Batali into chef-client to perform cookbook resolution locally on the node and request the solution set from the Chef Server.

Origin of the infusion

There are some claims that the solver the Chef Server uses can provide incorrect solutions. Though these are only claims, it prompted the question:

Can a client side solver be used to generate a solution?

As it turns out, it can!

Usage

Install

This is tested for Chef versions '~> 12.2'. If Chef is running via the omnibus install the gem should be installed like so:

$ /opt/chef/emebedded/bin/gem install batali-infuse --no-document

If Chef is running via the system Ruby, just install the gem directly:

$ gem install batali-infuse --no-document

Enable

The infusion is enabled via the client.rb file. Add the following line to the top of the file:

# /etc/chef/client.rb

require 'batali-infuse/sync'

Least impact resolution

Batali includes a "least impact" feature when resolving cookbooks. This feature can be enabled when resolving cookbooks on the local node. The benefit of least impact updates is that nodes will not automatically request the latest version of a cookbook available if it has already been provisioned. Instead, it will use a "least impact" approach when resolving cookbooks, and no update will occur if the previous version is still available within the given constraints.

There are two ways the option can be enabled:

Node attribute

node.set[:batali][:least_impact] = true

Chef configuration

# /etc/chef/client.rb
...
batali_least_impact true

NOTE: Enabling via the configuration file will override a disabled setting within the node attributes

Info

Resolver

• Batali: https://github.com/hw-labs/batali
• Least impact updates: https://github.com/hw-labs/batali#least-impact-updates

General

• Repository: https://github.com/hw-labs/batali-infuse
• IRC: Freenode @ #heavywater