Use the ohai resource to reload the Ohai configuration on a node. This allows recipes that change system attributes (like a recipe that adds a user) to refer to those attributes later on during the chef-client run.
A ohai resource block reloads the Ohai configuration on a node:
ohai 'reload' do action :reload end
The full syntax for all of the properties that are available to the ohai resource is:
ohai 'name' do name String notifies # see description plugin String provider Chef::Provider::Ohai subscribes # see description action Symbol # defaults to :reload if not specified end
where
ohai
is the resourcename
is the name of the resource block:action
identifies the steps the chef-client will take to bring the node into the desired statename
, plugin
, and provider
are properties of this resource, with the Ruby type shown. See “Properties” section below for more information about all of the properties that may be used with this resource.This resource has the following actions:
:nothing
:reload
This resource has the following properties:
ignore_failure
Ruby Types: TrueClass, FalseClass
Continue running a recipe if a resource fails for any reason. Default value: false
.
name
Ruby Type: String
Always the same value as the name
of the resource block. See “Syntax” section above for more information.
notifies
Ruby Type: Symbol, ‘Chef::Resource[String]’
A resource may notify another resource to take action when its state changes. Specify a 'resource[name]'
, the :action
that resource should take, and then the :timer
for that action. A resource may notifiy more than one resource; use a notifies
statement for each resource to be notified.
A timer specifies the point during the chef-client run at which a notification is run. The following timers are available:
:before
:delayed
:immediate
, :immediately
The syntax for notifies
is:
notifies :action, 'resource[name]', :timer
plugin
Ruby Type: String
Optional. The name of an Ohai plugin to be reloaded. If this property is not specified, the chef-client will reload all plugins.
provider
Ruby Type: Chef Class
Optional. Explicitly specifies a provider.
retries
Ruby Type: Integer
The number of times to catch exceptions and retry the resource. Default value: 0
.
retry_delay
Ruby Type: Integer
The retry delay (in seconds). Default value: 2
.
subscribes
Ruby Type: Symbol, ‘Chef::Resource[String]’
A resource may listen to another resource, and then take action if the state of the resource being listened to changes. Specify a 'resource[name]'
, the :action
to be taken, and then the :timer
for that action.
A timer specifies the point during the chef-client run at which a notification is run. The following timers are available:
:before
:delayed
:immediate
, :immediately
The syntax for subscribes
is:
subscribes :action, 'resource[name]', :timer
The following examples demonstrate various approaches for using resources in recipes. If you want to see examples of how Chef uses resources in recipes, take a closer look at the cookbooks that Chef authors and maintains: https://github.com/chef-cookbooks.
Reload Ohai
ohai 'reload' do action :reload end
Reload Ohai after a new user is created
ohai 'reload_passwd' do action :nothing plugin 'etc' end user 'daemonuser' do home '/dev/null' shell '/sbin/nologin' system true notifies :reload, 'ohai[reload_passwd]', :immediately end ruby_block 'just an example' do block do # These variables will now have the new values puts node['etc']['passwd']['daemonuser']['uid'] puts node['etc']['passwd']['daemonuser']['gid'] end end
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https://docs-archive.chef.io/release/12-13/resource_ohai.html