sysctl

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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

This 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'
   notifies                   # see description
   subscribes                 # see description
   value                      Array, String, Integer, Float # required
   action                     Symbol # defaults to :apply if not specified
end

where:

  • sysctl is the resource
  • 'name' is the kernel parameter, or the name of the resource block
  • conf_dir, ignore_error, key, notifies, subscribes, and value are the resources available to this property

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

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 paramater 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 very 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 very 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 Types: Array, String, Integer, Float

Required. The value to set.