sudo resource

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Use the sudo resource to add or remove individual sudo entries using sudoers.d files. Sudo version 1.7.2 or newer is required to use the sudo resource, as it relies on the #includedir directive introduced in version 1.7.2. This resource does not enforce installation of the required sudo version. Chef-supported releases of Ubuntu, Debian and RHEL (6+) all support this feature.

New in Chef Client 14.0.

Syntax

The sudo resource has the following syntax:

sudo 'name' do
  command_aliases        Array
  commands               Array # default value: ["ALL"]
  config_prefix          String # default value: Prefix values based on the node's platform
  defaults               Array
  env_keep_add           Array
  env_keep_subtract      Array
  filename               String # default value: 'name' unless specified
  groups                 String, Array
  host                   String # default value: "ALL"
  noexec                 true, false # default value: false
  nopasswd               true, false # default value: false
  runas                  String # default value: "ALL"
  setenv                 true, false # default value: false
  template               String
  users                  String, Array
  variables              Hash
  visudo_binary          String # default value: "/usr/sbin/visudo"
  visudo_path            String
  action                 Symbol # defaults to :create if not specified
end

where:

  • sudo 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.
  • command_aliases, commands, config_prefix, defaults, env_keep_add, env_keep_subtract, filename, groups, host, noexec, nopasswd, runas, setenv, template, users, variables, visudo_binary, and visudo_path are the properties available to this resource.

Actions

The sudo resource has the following actions:

:create
Default. Create a single sudoers configuration file in the sudoers.d directory.
:delete
Removed a sudoers configuration file from the sudoers.d directory.
: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 the Chef Client run.

Properties

The sudo resource has the following properties:

command_aliases

Ruby Type: Array

Command aliases that can be used as allowed commands later in the configuration.

commands

Ruby Type: Array | Default Value: ["ALL"]

An array of commands this sudoer can execute.

config_prefix

Ruby Type: String | Default Value: Prefix values based on the node's platform

The directory that contains the sudoers configuration file.

defaults

Ruby Type: Array

An array of defaults for the user/group.

env_keep_add

Ruby Type: Array

An array of strings to add to env_keep.

env_keep_subtract

Ruby Type: Array

An array of strings to remove from env_keep.

filename

Ruby Type: String | Default Value: The resource block's name

The name of the sudoers.d file, if it differs from the name of the resource block

groups

Ruby Type: String, Array

Group(s) to provide sudo privileges to. This property accepts either an array or a comma-separated list. Leading % on group names is optional.

host

Ruby Type: String | Default Value: "ALL"

The host to set in the sudo configuration.

noexec

Ruby Type: true, false | Default Value: false

Prevent commands from shelling out.

nopasswd

Ruby Type: true, false | Default Value: false

Allow sudo to be run without specifying a password.

runas

Ruby Type: String | Default Value: "ALL"

User that the command(s) can be run as.

setenv

Ruby Type: true, false | Default Value: false

Determines whether or not to permit preservation of the environment with sudo -E.

template

Ruby Type: String

The name of the .erb template in your cookbook, if you wish to supply your own template.

users

Ruby Type: String, Array

User(s) to provide sudo privileges to. This property accepts either an array or a comma-separated list.

variables

Ruby Type: Hash

The variables to pass to the custom template. This property is ignored if not using a custom template.

visudo_binary

Ruby Type: String | Default Value: /usr/sbin/visudo

The path to visudo for configuration verification.

Common Resource Functionality

Chef resources include common properties, notifications, and resource guards.

Common Properties

The following properties are common to every resource:

ignore_failure

Ruby Type: true, false | Default Value: false

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

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).

sensitive

Ruby Type: true, false | Default Value: false

Ensure that sensitive resource data is not logged by the chef-client.

Notifications

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
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

Guards

A guard property can be used to evaluate the state of a node during the execution phase of the chef-client run. Based on the results of this evaluation, a guard property is then used to tell the chef-client if it should continue executing a resource. A guard property accepts either a string value or a Ruby block value:

  • A string is executed as a shell command. If the command returns 0, the guard is applied. If the command returns any other value, then the guard property is not applied. String guards in a powershell_script run Windows PowerShell commands and may return true in addition to 0.
  • A block is executed as Ruby code that must return either true or false. If the block returns true, the guard property is applied. If the block returns false, the guard property is not applied.

A guard property is useful for ensuring that a resource is idempotent by allowing that resource to test for the desired state as it is being executed, and then if the desired state is present, for the chef-client to do nothing.

The following properties can be used to define a guard that is evaluated during the execution phase of the chef-client run:

not_if
Prevent a resource from executing when the condition returns true.
only_if
Allow a resource to execute only if the condition returns true.

Examples

Grant a user sudo privileges for any command

sudo 'admin' do
  user 'admin'
end

Grant a user and groups sudo privileges for any command

sudo 'admins' do
  users 'bob'
  groups 'sysadmins, superusers'
end

Grant passwordless sudo privileges for specific commands

sudo 'passwordless-access' do
  commands ['systemctl restart httpd', 'systemctl restart mysql']
  nopasswd true
end