machine_execute¶

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Use the machine_execute resource to run a command on a remote machine in much the same way the execute resource is used to run a command on a local machine.

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.

Syntax¶

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

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

where

machine_execute tells the chef-client to use the Chef::Provider::MachineExecute provider during the chef-client run
name is the name of the resource block; when the command property is not specified as part of a recipe, name is also the command to be run
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:

: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.
:run: Default. Use to run a machine.

Properties¶

This resource has the following properties:

chef_server

Ruby Type: Hash

The URL for the Chef server.

command

Ruby Type: String

The name of the command to be executed. Default value: the name of the resource block. See “Syntax” section above for more information.

driver

Ruby Type: Chef::Provisioning::Driver

Use to specify the driver to be used for provisioning.

ignore_failure

Ruby Type: true, false | Default Value: false

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

live_stream

Ruby Type: true, false | Default Value: false

machine

Ruby Type: String

Use to specify the machine type.

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¶

None.