This cookbook introduces weight property on resources.
This notion emerged during a discussion of London chef summit in Oct 2016.
Our need was to qualify resources with a high impact (i.e that cause downtime on the node) such as reboots, reinstallation, some service restarts. Those resources would be protected automatically by a choregraphie.
This would solve the necessity to manually manage lists of these resources.
Someone suggested to generalize the high impact flag by a weight property to use it for other use cases.
Example use cases:
- graph impact of chef-client run over time (weighting each resource)
- adopt rules to avoid running chef-client during peak hours if its impact has a weigh above a threshold
- simplify definitions of choregraphies
Note: The intent of this cookbook is to validate the interest of a feature that could be integrated in chef.
All resources now have a property weight.
In recipes:
service 'network' do
weight 5
action :start
end
execute 'something' do
action :restart, 'service[network]'
end
It is possible to add a default weight to all instances of a given resource.
In attributes:
default['resource-weight']['reboot']['default-weight'] = 5
