dnf_package resource

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Use the dnf_package resource to install, upgrade, and remove packages with DNF for Fedora platforms. The dnf_package resource is able to resolve provides data for packages much like DNF can do when it is run from the command line. This allows a variety of options for installing packages, like minimum versions, virtual provides, and library names.

Note

In many cases, it is better to use the package resource instead of this one. This is because when the package resource is used in a recipe, the chef-client will use details that are collected by Ohai at the start of the chef-client run to determine the correct package application. Using the package resource allows a recipe to be authored in a way that allows it to be used across many platforms.

Syntax

A dnf_package resource block manages a package on a node, typically by installing it. The simplest use of the dnf_package resource is:

dnf_package 'package_name'

which will install the named package using all of the default options and the default action (:install).

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

dnf_package 'name' do
  arch                         String, Array
  flush_cache                  Hash # default value: {"before"=>false, "after"=>false}
  options                      String, Array
  package_name                 String, Array
  source                       String
  timeout                      String, Integer
  version                      String, Array
  action                       Symbol # defaults to :install if not specified
end

where:

  • dnf_package 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.
  • arch, flush_cache, options, package_name, source, timeout, and version are the properties available to this resource.

Actions

The dnf_package resource has the following actions:

:install
Default. Install a package. If a version is specified, install the specified version of the package.
:lock
Locks the DNF package to a specific version.
: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.
:purge
Purge a package. This action typically removes the configuration files as well as the package.
:remove
Remove a package.
:unlock
Unlocks the DNF package so that it can be upgraded to a newer version.
:upgrade
Install a package and/or ensure that a package is the latest version. This action will ignore the version attribute.

Properties

The dnf_package resource has the following properties:

arch

Ruby Type: String, Array

The architecture of the package to be installed or upgraded. This value can also be passed as part of the package name.

flush_cache

Ruby Type: Array

Flush the in-memory cache before or after a DNF operation that installs, upgrades, or removes a package. Default value: [ :before, :after ]. The value may also be a Hash: ( { :before => true/false, :after => true/false } ).

DNF automatically synchronizes remote metadata to a local cache. The chef-client creates a copy of the local cache, and then stores it in-memory during the chef-client run. The in-memory cache allows packages to be installed during the chef-client run without the need to continue synchronizing the remote metadata to the local cache while the chef-client run is in-progress.

As an array:

dnf_package 'some-package' do
  #...
  flush_cache [ :before ]
  #...
end

and as a Hash:

dnf_package 'some-package' do
  #...
  flush_cache( { :after => true } )
  #...
end

Note

The flush_cache property does not flush the local DNF cache! Use dnf tools—dnf clean metadata, dnf clean packages, dnf clean all—to clean the local DNF cache.

options

Ruby Type: String, Array

One (or more) additional command options that are passed to the command.

package_name

Ruby Type: String, Array

One of the following: the name of a package, the name of a package and its architecture, the name of a dependency. Default value: the name of the resource block. See “Syntax” section above for more information.

source

Ruby Type: String

Optional. The path to a package in the local file system.

timeout

Ruby Type: String, Integer

The amount of time (in seconds) to wait before timing out.

version

Ruby Type: String, Array

The version of a package to be installed or upgraded. This property is ignored when using the :upgrade action.

Multiple Packages

A resource may specify multiple packages and/or versions for platforms that use Yum, DNF, Apt, Zypper, or Chocolatey package managers. Specifying multiple packages and/or versions allows a single transaction to:

  • Download the specified packages and versions via a single HTTP transaction
  • Update or install multiple packages with a single resource during the chef-client run

For example, installing multiple packages:

package %w(package1 package2)

Installing multiple packages with versions:

package %w(package1 package2) do
  version [ '1.3.4-2', '4.3.6-1']
end

Upgrading multiple packages:

package %w(package1 package2)  do
  action :upgrade
end

Removing multiple packages:

package %w(package1 package2)  do
  action :remove
end

Purging multiple packages:

package %w(package1 package2)  do
  action :purge
end

Notifications, via an implicit name:

package %w(package1 package2)  do
  action :nothing
end

log 'call a notification' do
  notifies :install, 'package[package1, package2]', :immediately
end

Note

Notifications and subscriptions do not need to be updated when packages and versions are added or removed from the package_name or version properties.

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

The following examples demonstrate various approaches for using resources in recipes:

Install an exact version

dnf_package 'netpbm = 10.35.58-8.el5'

Install a minimum version

dnf_package 'netpbm >= 10.35.58-8.el5'

Install a minimum version using the default action

dnf_package 'netpbm'

To install a package

dnf_package 'netpbm' do
  action :install
end

To install a partial minimum version

dnf_package 'netpbm >= 10'

To install a specific architecture

dnf_package 'netpbm' do
  arch 'i386'
end

or:

dnf_package 'netpbm.x86_64'

To install a specific version-release

dnf_package 'netpbm' do
  version '10.35.58-8.el5'
end

To install a specific version (even when older than the current)

dnf_package 'tzdata' do
  version '2011b-1.el5'
end

Handle cookbook_file and dnf_package resources in the same recipe

When a cookbook_file resource and a dnf_package resource are both called from within the same recipe, use the flush_cache attribute to dump the in-memory DNF cache, and then use the repository immediately to ensure that the correct package is installed:

cookbook_file '/etc/yum.repos.d/custom.repo' do
  source 'custom'
  mode '0755'
end

dnf_package 'only-in-custom-repo' do
  action :install
  flush_cache [ :before ]
end