apt_preference resource¶

[edit on GitHub]

The apt_preference resource allows for the creation of APT preference files. Preference files are used to control which package versions and sources are prioritized during installation.

New in Chef Client 13.3.

Syntax¶

The apt_preference resource has the following syntax:

apt_preference 'name' do
  glob              String
  package_name      String # default value: 'name' unless specified
  pin               String
  pin_priority      String, Integer
  action            Symbol # defaults to :add if not specified
end

where:

apt_preference 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.
glob, package_name, pin, and pin_priority are the properties available to this resource.

Actions¶

The apt_preference resource has the following actions:

add: Default action. Creates a preferences file under /etc/apt/preferences.d.
remove: Removes the preferences file, thus unpinning the package.

Properties¶

The apt_preference resource has the following properties:

glob

Ruby Type: String

Pin by glob() expression or with regular expressions surrounded by /.

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

package_name

Ruby Type: String

The name of the package. Default value: name.

pin

Ruby Type: String

The package version or repository to pin.

pin_priority

Ruby Type: String, Integer

Sets the Pin-Priority for a package. See the APT pinning documentation for more details.

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

Examples¶

Pin a package to a specific version

This example pins the libmysqlclient16 package to version 5.1.49-3:

apt_preference 'libmysqlclient16' do
  pin          'version 5.1.49-3'
  pin_priority '700'
end

Note that the pin_priority of 700 ensures that this version will be preferred over any other available versions.

Unpin a package

This example unpins the libmysqlclient16 package, disabling all preferences for it:

apt_preference 'libmysqlclient16' do
  action :remove
end

Pin all packages to prefer a specific repository

This example instructs APT to prefer the packages.dotdeb.org repository:

apt_preference 'dotdeb' do
  glob         '*'
  pin          'origin packages.dotdeb.org'
  pin_priority '700'
end