group

[edit on GitHub]

Use the group resource to manage a local group.

Syntax

A group resource block manages groups on a node:

group 'www-data' do
  action :modify
  members 'maintenance'
  append true
end

The full syntax for all of the properties that are available to the group resource is:

group 'name' do
  append                     TrueClass, FalseClass
  excluded_members           Array
  gid                        String, Integer
  group_name                 String # defaults to 'name' if not specified
  members                    Array
  non_unique                 TrueClass, FalseClass
  notifies                   # see description
  provider                   Chef::Provider::Group
  subscribes                 # see description
  system                     TrueClass, FalseClass
  action                     Symbol # defaults to :create if not specified
end

where

  • group is the resource
  • name is the name of the resource block
  • action identifies the steps the chef-client will take to bring the node into the desired state
  • append, excluded_members, gid, group_name, members, non_unique, provider, and system are properties of this resource, with the Ruby type shown. See “Properties” section below for more information about all of the properties that may be used with this resource.

Actions

This resource has the following actions:

:create
Default. Create a group. If a group already exists (but does not match), update that group to match.
:manage
Manage an existing group. This action does nothing if the group does not exist.
:modify
Modify an existing group. This action raises an exception if the group does not exist.
: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.
:remove
Remove a group.

Properties

This resource has the following properties:

append

Ruby Types: TrueClass, FalseClass

How members should be appended and/or removed from a group. When true, members are appended and excluded_members are removed. When false, group members are reset to the value of the members property. Default value: false.

excluded_members

Ruby Type: Array

Remove users from a group. May only be used when append is set to true.

gid

Ruby Types: String, Integer

The identifier for the group.

group_name

Ruby Type: String

The name of the group. Default value: the name of the resource block See “Syntax” section above for more information.

ignore_failure

Ruby Types: TrueClass, FalseClass

Continue running a recipe if a resource fails for any reason. Default value: false.

members

Ruby Type: Array

Which users should be set or appended to a group. When more than one group member is identified, the list of members should be an array: members ['user1', 'user2'].

non_unique

Ruby Types: TrueClass, FalseClass

Allow gid duplication. May only be used with the Groupadd provider. Default value: false.

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
provider

Ruby Type: Chef Class

Optional. Explicitly specifies a provider. See “Providers” section below for more information.

retries

Ruby Type: Integer

The number of times to catch exceptions and retry the resource. Default value: 0.

retry_delay

Ruby Type: Integer

The retry delay (in seconds). Default value: 2.

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
system

Ruby Types: TrueClass, FalseClass

Show if a group belongs to a system group. Set to true if the group belongs to a system group.

Providers

Where a resource represents a piece of the system (and its desired state), a provider defines the steps that are needed to bring that piece of the system from its current state into the desired state.

The chef-client will determine the correct provider based on configuration data collected by Ohai at the start of the chef-client run. This configuration data is then mapped to a platform and an associated list of providers.

Generally, it’s best to let the chef-client choose the provider, and this is (by far) the most common approach. However, in some cases, specifying a provider may be desirable. There are two approaches:

  • Use a more specific short name—yum_package "foo" do instead of package "foo" do, script "foo" do instead of bash "foo" do, and so on—when available
  • Use the provider property within the resource block to specify the long name of the provider as a property of a resource. For example: provider Chef::Provider::Long::Name

This resource has the following providers:

Chef::Provider::Group, group
When this short name is used, the chef-client will determine the correct provider during the chef-client run.
Chef::Provider::Group::Aix, group
The provider for the AIX platform.
Chef::Provider::Group::Dscl, group
The provider for the macOS platform.
Chef::Provider::Group::Gpasswd, group
The provider for the gpasswd command.
Chef::Provider::Group::Groupadd, group
The provider for the groupadd command.
Chef::Provider::Group::Groupmod, group
The provider for the groupmod command.
Chef::Provider::Group::Pw, group
The provider for the FreeBSD platform.
Chef::Provider::Group::Suse, group
The provider for the openSUSE platform.
Chef::Provider::Group::Usermod, group
The provider for the Solaris platform.
Chef::Provider::Group::Windows, group
The provider for the Microsoft Windows platform.

Examples

The following examples demonstrate various approaches for using resources in recipes. If you want to see examples of how Chef uses resources in recipes, take a closer look at the cookbooks that Chef authors and maintains: https://github.com/chef-cookbooks.

Append users to groups

group 'www-data' do
  action :modify
  members 'maintenance'
  append true
end

Add a user to group on the Windows platform

group 'Administrators' do
  members ['domain\foo']
  append true
  action :modify
end