chef_node Resource

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A node is any device—physical, virtual, cloud, network device, etc.—that is under management by Chef Infra.

Use the chef_node resource to manage nodes.

Syntax

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

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

where:

• chef_node tells Chef Infra Client to use the Chef::Provider::ChefNode provider during a Chef Infra Client run
• name is the name of the resource block
• attribute is zero (or more) of the properties that are available for this resource
• action identifies which steps Chef Infra Client will take to bring the node into the desired state

Actions

The chef_node resource has the following actions:

:create

Default. Use to create a node.

:delete

Use to delete a node.

:nothing

This resource block does not act unless notified by another resource to take action. Once notified, this resource block either runs immediately or is queued up to run at the end of a Chef Infra Client run.

Properties

The chef_node resource has the following properties:

automatic_attributes

An automatic attribute contains data that is identified by Ohai at the beginning of every Chef Infra Client run. An automatic attribute cannot be modified and always has the highest attribute precedence.

Default value: {}.

chef_environment

The Chef Infra Server environment in which this node should exist (or does exist).

chef_server

The URL for the Chef Infra Server.

complete

Use to specify if this resource defines a node completely. When true, any property not specified by this resource will be reset to default property values.

default_attributes

A default attribute is automatically reset at the start of every Chef Infra Client run and has the lowest attribute precedence. Use default attributes as often as possible in cookbooks.

Default value: {}.

ignore_failure

Ruby Type: true, false | Default Value: false

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

name

The unique identifier of the node.

normal_attributes

A normal attribute is a setting that persists in the node object. A normal attribute has a higher attribute precedence than a default attribute.

Default value: {}.

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.

If the referenced resource does not exist, an error is raised. In contrast, subscribes will not fail if the source resource is not found.

A timer specifies the point during a Chef Infra 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 a Chef Infra 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

override_attributes

An override attribute is automatically reset at the start of every Chef Infra Client run and has a higher attribute precedence than default, force_default, and normal attributes. An override attribute is most often specified in a recipe, but can be specified in an attribute file, for a role, and/or for an environment. A cookbook should be authored so that it uses override attributes only when required.

Default value: {}.

raw_json

The node as JSON data. For example:

{
  "overrides": {},
  "name": "latte",
  "chef_type": "node",
  "json_class": "Chef::Node",
  "attributes": {
    "hardware_type": "laptop"
  },
  "run_list": [
    "recipe[apache2]"
  ],
  "defaults": {}
}

retries

Ruby Type: Integer | Default Value: 0

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

retry_delay

Ruby Type: Integer | Default Value: 2

The retry delay (in seconds).

run_list

A comma-separated list of roles and/or recipes to be applied. Default value: []. For example: ["recipe[default]","recipe[apache2]"]

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.

If the other resource does not exist, the subscription will not raise an error. Contrast this with the stricter semantics of notifies, which will raise an error if the other resource does not exist.

A timer specifies the point during a Chef Infra 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 a Chef Infra 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

This resource does not have any examples.