sysctl resource¶

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Use the sysctl resource to set or remove kernel parameters using the sysctl command line tool and configuration files in the system’s sysctl.d directory. Configuration files managed by this resource are named 99-chef-KEYNAME.conf. If an existing value was already set, it will be backed up to the node and restored if the :remove action is used later.

New in Chef Client 14.0.

Syntax¶

The sysctl resource has the following syntax:

sysctl 'name' do
  conf_dir          String # default value: /etc/sysctl.d
  ignore_error      true, false # default value: false
  key               String # default value: 'name' unless specified
  value             Array, String, Integer, Float
  action            Symbol # defaults to :apply if not specified
end

where:

sysctl is the resource.
name is the name given to the resource block.
action identifies which steps the chef-client will take to bring the node into the desired state.
conf_dir, ignore_error, key, and value are the properties available to this resource.

Actions¶

The sysctl resource has the following actions:

:apply: Default. Set the kernel parameter and update the sysctl settings.
:remove: Remove the kernel parameter and update the sysctl settings.
:nothing: Define this resource block to do nothing until notified by another resource to take action. When this resource is notified, this resource block is either run immediately or it is queued up to be run at the end of the Chef Client run.

Properties¶

The sysctl resource has the following properties:

conf_dir

Ruby Type: String | Default Value: /etc/sysctl.d

The configuration directory to write the config to.

ignore_error

Ruby Type: true, false | Default Value: false

Ignore any errors when setting the value on the command line.

key

Ruby Type: String | Default Value: 'name'

The kernel parameter key in dotted format, if it differs from the resource block name.

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 notify 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: Specifies that the action on a notified resource should be run before processing the resource block in which the notification is located.
:delayed: Default. Specifies that a notification should be queued up, and then executed at the end of the Chef Client run.
:immediate, :immediately: Specifies that a notification should be run immediately, per resource notified.

The syntax for notifies is:

notifies :action, 'resource[name]', :timer

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.

Note that subscribes does not apply the specified action to the resource that it listens to - for example:

file '/etc/nginx/ssl/example.crt' do
   mode '0600'
   owner 'root'
end

service 'nginx' do
   subscribes :reload, 'file[/etc/nginx/ssl/example.crt]', :immediately
end

In this case the subscribes property reloads the nginx service whenever its certificate file, located under /etc/nginx/ssl/example.crt, is updated. subscribes does not make any changes to the certificate file itself, it merely listens for a change to the file, and executes the :reload action for its resource (in this example nginx) when a change is detected.

A timer specifies the point during the Chef Client run at which a notification is run. The following timers are available:

:before: Specifies that the action on a notified resource should be run before processing the resource block in which the notification is located.
:delayed: Default. Specifies that a notification should be queued up, and then executed at the end of the Chef Client run.
:immediate, :immediately: Specifies that a notification should be run immediately, per resource notified.

The syntax for subscribes is:

subscribes :action, 'resource[name]', :timer

value

Ruby Type: Array, String, Integer, Float

Required. The value to set.