chef_client

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Warning

This functionality is available with Chef provisioning and is packaged in the Chef development kit. Chef provisioning is a framework that allows clusters to be managed by the chef-client and the Chef server in the same way nodes are managed: with recipes. Use Chef provisioning to describe, version, deploy, and manage clusters of any size and complexity using a common set of tools.

A chef-client is an agent that runs locally on every node that is under management by Chef. When a chef-client is run, it will perform all of the steps that are required to bring the node into the expected state, including:

  • Registering and authenticating the node with the Chef server
  • Building the node object
  • Synchronizing cookbooks
  • Compiling the resource collection by loading each of the required cookbooks, including recipes, attributes, and all other dependencies
  • Taking the appropriate and required actions to configure the node
  • Looking for exceptions and notifications, handling each as required

Use the chef_client resource to manage clients.

Syntax

The syntax for using the chef_client resource in a recipe is as follows:

chef_client 'name' do
  attribute 'value' # see properties section below
  ...
  action :action # see actions section below
end

where

  • chef_client tells the chef-client to use the Chef::Provider::ChefClient provider during the chef-client run
  • name is the name of the resource block; when the name property is not specified as part of a recipe, name is also the name of the chef-client
  • attribute is zero (or more) of the properties that are available for this resource
  • action identifies which steps the chef-client will take to bring the node into the desired state

Actions

This resource has the following actions:

:create
Default. Use to create a chef-client.
:delete
Use to delete a chef-client.
: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.
:regenerate_keys
Use to regenerate the RSA public key for a chef-client.

Properties

This resource has the following properties:

admin
Use to specify whether the chef-client is an API client.
chef_server
The URL for the Chef server.
complete
Use to specify if this resource defines a chef-client completely. When true, any property not specified by this resource will be reset to default property values.
ignore_failure

Ruby Type: true, false | Default Value: false

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

name
The name of the chef-client.
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
output_key_format
Use to specify the format of a public key. Possible values: pem, der, or openssh. Default value: openssh.
output_key_path
Use to specify the path to the location in which a public key will be written.
raw_json

The chef-client as JSON data. For example:

{
  "clientname": "client_name",
  "orgname": "org_name",
  "validator": false,
  "certificate": "-----BEGIN CERTIFICATE-----\n
                  ...
                  1234567890abcdefghijklmnopq\n
                  ...
                  -----END CERTIFICATE-----\n",
  "name": "node_name"
}
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).

source_key
Use to copy a public or private key, but apply a different format and password. Use in conjunction with source_key_pass_phrase` and source_key_path.
source_key_pass_phrase
The pass phrase for the public key. Use in conjunction with source_key` and source_key_path.
source_key_path
The path to the public key. Use in conjunction with source_key` and source_key_pass_phrase.
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
validator
Use to specify if the chef-client is a chef-validator.

Examples

None.