hostname

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The hostname resource sets the system’s hostname and hosts configuration, ensures that the hostname persists after a reboot, and then re-run the Ohai plugin so the hostname will be available in subsequent cookbooks.

New in Chef Client 14.0

Syntax

Here’s the full syntax of this resource’s properties and actions:

hostname 'name' do
  aliases                    Array, nil # defaults to 'nil'
  compile_time               True, False # default to 'true'
  hostname                   String # default value: 'name'
  ipaddress                  String # see description
  notifies                   # see description
  subscribes                 # see description
  windows_reboot             True, False # defaults to 'true'
  action                     Symbol # defaults to :set if not specified

where:

  • hostname is the name of the resource
  • 'name' is the desired hostname, or name of the resource block
  • action identifies the steps the chef-client will take to bring the node to the desired state
  • aliases, compile_time, hostname, ipaddress, and windows_reboot are the properties available to this resource

Actions

This resource has the following actions:

:set
Default action. Set the node’s hostname.
:nothing
Define this resource block to do nothing until notified by another resource to take action. When this resource is notified, the resource block is either run immediately or it is queued up to be run at the end of the Chef Client run.

Properties

This resource has the following properties:

aliases

Ruby Types: Array, nil | Default Value: nil

An array of hostname aliases to use when configuring the hosts file.

compile_time

Ruby Types: True, False | Default Value: true

Determines whether or not the resource shoul be run at compile time.

hostname

Ruby Type: String | Default Value: 'name'

Used to specify the hostname if it is different than the resource’s name.

ipaddress

Ruby Type: String | Default Value: lazy { node["ipaddress"] }

The IP address to use when configuring the hosts file. By default, this uses node["ipaddress"] information collected by Ohai.

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
windows_reboot

Ruby Types: True, False | Default Value: true

Determines whether or not Windows should be reboot after changing the hostname, as this is required for the change to take effect.

Examples

Set the hostname

hostname 'example' do

The example above sets the hostname to example for the IP address, as detected by Ohai.

Manually specify the hostname and IP address

hostname 'statically_configured_host' do
  hostname 'example'
  ipaddress '198.51.100.2'
end