apt_update resource

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Use the apt_update resource to manage APT repository updates on Debian and Ubuntu platforms.

Syntax

An apt_update resource block defines the update frequency for APT repositories:

apt_update 'name' do
  frequency      Integer # default value: 86400
  action         Symbol # defaults to :periodic if not specified
end

where:

  • apt_update 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.
  • frequency is the property available to this resource.

Nameless

This resource can be nameless. Add the resource itself to your recipe to get the default behavior:

apt_update

will behave the same as:

apt_update 'update'

Actions

This resource has the following actions:

: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.
:periodic
Update the Apt repository at the interval specified by the frequency property.
:update
Update the Apt repository at the start of the chef-client run.

Properties

This resource has the following properties:

frequency

Ruby Type: Integer | Default Value: 86400

Determines how frequently (in seconds) APT repository updates are made. Use this property when the :periodic action is specified.

ignore_failure

Ruby Types: true, false | Default Value: false

Continue running a recipe if a resource fails for any reason.

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
retries

Ruby Type: Integer | Default Value: 0

The number of times to catch exceptions and retry the resource.

retry_delay

Ruby Type: Integer | Default Value: 2

The retry delay (in seconds).

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

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.

Update the Apt repository at a specified interval

apt_update 'all platforms' do
  frequency 86400
  action :periodic
end

Update the Apt repository at the start of a chef-client run

apt_update 'update'