gem_package

Warning

The chef_gem and gem_package resources are both used to install Ruby gems. For any machine on which the chef-client is installed, there are two instances of Ruby. One is the standard, system-wide instance of Ruby and the other is a dedicated instance that is available only to the chef-client. Use the chef_gem resource to install gems into the instance of Ruby that is dedicated to the chef-client. Use the gem_package resource to install all other gems (i.e. install gems system-wide).

Use the gem_package resource to manage gem packages that are only included in recipes. When a package is installed from a local file, it must be added to the node using the remote_file or cookbook_file resources.

Note

The gem_package resource must be specified as gem_package and cannot be shortened to package in a recipe.

Syntax

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

gem_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 gem_package resource is:

gem_package 'name' do
  clear_sources              TrueClass, FalseClass
  gem_binary                 String
  notifies                   # see description
  options                    String
  package_name               String, Array # defaults to 'name' if not specified
  provider                   Chef::Provider::Package::Rubygems
  source                     String
  subscribes                 # see description
  timeout                    String, Integer
  version                    String, Array
  action                     Symbol # defaults to :install if not specified
end

where

  • gem_package tells the chef-client to manage a package
  • 'name' is the name of the package
  • :action identifies which steps the chef-client will take to bring the node into the desired state
  • clear_sources, gem_binary, options, package_name, provider, source, timeout, and version 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.

Gem Package Options

The RubyGems package provider attempts to use the RubyGems API to install gems without spawning a new process, whenever possible. A gems command to install will be spawned under the following conditions:

  • When a gem_binary property is specified (as a hash, a string, or by a .gemrc file), the chef-client will run that command to examine its environment settings and then again to install the gem.
  • When install options are specified as a string, the chef-client will span a gems command with those options when installing the gem.
  • The omnibus installer will search the PATH for a gem command rather than defaulting to the current gem environment. As part of enforce_path_sanity, the bin directories area added to the PATH, which means when there are no other proceeding RubyGems, the installation will still be operated against it.

Specify with Hash

If an explicit gem_binary parameter is not being used with the gem_package resource, it is preferable to provide the install options as a hash. This approach allows the provider to install the gem without needing to spawn an external gem process.

The following RubyGems options are available for inclusion within a hash and are passed to the RubyGems DependencyInstaller:

  • :env_shebang
  • :force
  • :format_executable
  • :ignore_dependencies
  • :prerelease
  • :security_policy
  • :wrappers

For more information about these options, see the RubyGems documentation: http://rubygems.rubyforge.org/rubygems-update/Gem/DependencyInstaller.html.

Example

gem_package 'bundler' do
  options(:prerelease => true, :format_executable => false)
end

Specify with String

When using an explicit gem_binary, options must be passed as a string. When not using an explicit gem_binary, the chef-client is forced to spawn a gems process to install the gems (which uses more system resources) when options are passed as a string. String options are passed verbatim to the gems command and should be specified just as if they were passed on a command line. For example, --prerelease for a pre-release gem.

Example

gem_package 'nokogiri' do
  gem_binary('/opt/ree/bin/gem')
  options('--prerelease --no-format-executable')
end

Specify with .gemrc File

Options can be specified in a .gemrc file. By default the gem_package resource will use the Ruby interface to install gems which will ignore the .gemrc file. The gem_package resource can be forced to use the gems command instead (and to read the .gemrc file) by adding the gem_binary attribute to a code block.

Example

A template named gemrc.erb is located in a cookbook’s /templates directory:

:sources:
- http://<%= node['gem_file']['host'] %>:<%= node['gem_file']['port'] %>/

A recipe can be built that does the following:

  • Builds a .gemrc file based on a gemrc.erb template
  • Runs a Gem.configuration command
  • Installs a package using the .gemrc file
template '/root/.gemrc' do
  source 'gemrc.erb'
  action :create
  notifies :run, 'ruby_block[refresh_gemrc]', :immediately
end

ruby_block 'refresh_gemrc' do
  action :nothing
  block do
    Gem.configuration = Gem::ConfigFile.new []
  end
end

gem_package 'di-ruby-lvm' do
  gem_binary '/opt/chef/embedded/bin/gem'
  action :install
end

Actions

This resource has the following actions:

:install
Default. Install a package. If a version is specified, install the specified version of the package.
: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.
:purge
Purge a package. This action typically removes the configuration files as well as the package.
:reconfig
Reconfigure a package. This action requires a response file.
:remove
Remove a package.
:upgrade
Install a package and/or ensure that a package is the latest version.

Properties

This resource has the following properties:

clear_sources

Ruby Types: TrueClass, FalseClass

Set to true to download a gem from the path specified by the source property (and not from RubyGems). Default value: false.

gem_binary

Ruby Type: String

A property for the gem_package provider that is used to specify a gems binary. By default, the same version of Ruby that is used by the chef-client will be installed.

ignore_failure

Ruby Types: TrueClass, FalseClass

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

Ruby Type: String

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

package_name

Ruby Types: String, Array

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

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.

source

Ruby Type: String

Optional. The URL at which the gem package is located.

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.

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
timeout

Ruby Types: String, Integer

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

version

Ruby Types: String, Array

The version of a package to be installed or upgraded.

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::Package, package
When this short name is used, the chef-client will attempt to determine the correct provider during the chef-client run.
Chef::Provider::Package::Rubygems, gem_package
Can be used with the options attribute.

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.

Install a gems file from the local file system

gem_package 'right_aws' do
  source '/tmp/right_aws-1.11.0.gem'
  action :install
end

Use the ignore_failure common attribute

gem_package 'syntax' do
  action :install
  ignore_failure true
end