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#
# Copyright:: Copyright (c) Chef Software Inc.
# Copyright:: 2016-2020, Virender Khatri
#
# License:: Apache License, Version 2.0
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
require_relative "../resource"
class Chef
class Resource
class Alternatives < Chef::Resource
unified_mode true
provides(:alternatives) { true }
description "Use the **alternatives** resource to configure command alternatives in Linux using the alternatives or update-alternatives packages."
introduced "16.0"
examples <<~DOC
**Install an alternative**:
```ruby
alternatives 'python install 2' do
link_name 'python'
path '/usr/bin/python2.7'
priority 100
action :install
end
```
**Set an alternative**:
```ruby
alternatives 'python set version 3' do
link_name 'python'
path '/usr/bin/python3'
action :set
end
```
**Set the automatic alternative state**:
```ruby
alternatives 'python auto' do
link_name 'python'
action :auto
end
```
**Refresh an alternative**:
```ruby
alternatives 'python refresh' do
link_name 'python'
action :refresh
end
```
**Remove an alternative**:
```ruby
alternatives 'python remove' do
link_name 'python'
path '/usr/bin/python3'
action :remove
end
```
DOC
property :link_name, String,
name_property: true,
description: "The name of the link to create. This will be the command you type on the command line such as `ruby` or `gcc`."
property :link, String,
default: lazy { |n| "/usr/bin/#{n.link_name}" },
default_description: "/usr/bin/LINK_NAME",
description: "The path to the alternatives link."
property :path, String,
description: "The absolute path to the original application binary such as `/usr/bin/ruby27`."
property :priority, [String, Integer],
coerce: proc { |n| n.to_i },
description: "The priority of the alternative."
def define_resource_requirements
requirements.assert(:install) do |a|
a.assertion do
!new_resource.priority.nil?
end
a.failure_message("Could not set alternatives for #{new_resource.link_name}, you must provide the :priority property")
end
requirements.assert(:install, :set, :remove) do |a|
a.assertion do
!new_resource.path.nil?
end
a.failure_message("Could not set alternatives for #{new_resource.link_name}, you must provide the :path property")
end
requirements.assert(:install, :set, :remove) do |a|
a.assertion do
::File.exist?(new_resource.path)
end
a.whyrun("Assuming file #{new_resource.path} already exists or was created already")
a.failure_message("Could not set alternatives for #{new_resource.link_name}, missing #{new_resource.path}")
end
end
action :install, description: "Install an alternative on the system including symlinks." do
if path_priority != new_resource.priority
converge_by("adding alternative #{new_resource.link} #{new_resource.link_name} #{new_resource.path} #{new_resource.priority}") do
output = shell_out(alternatives_cmd, "--install", new_resource.link, new_resource.link_name, new_resource.path, new_resource.priority)
unless output.exitstatus == 0
raise "failed to add alternative #{new_resource.link} #{new_resource.link_name} #{new_resource.path} #{new_resource.priority}"
end
end
end
end
action :set, description: "Set the symlink for an alternative." do
if current_path != new_resource.path
converge_by("setting alternative #{new_resource.link_name} #{new_resource.path}") do
output = shell_out(alternatives_cmd, "--set", new_resource.link_name, new_resource.path)
unless output.exitstatus == 0
raise "failed to set alternative #{new_resource.link_name} #{new_resource.path} \n #{output.stdout.strip}"
end
end
end
end
action :remove, description: "Remove an alternative and all associated links." do
if path_exists?
converge_by("removing alternative #{new_resource.link_name} #{new_resource.path}") do
shell_out(alternatives_cmd, "--remove", new_resource.link_name, new_resource.path)
end
end
end
action :auto, description: "Set an alternative up in automatic mode with the highest priority automatically selected." do
converge_by("setting auto alternative #{new_resource.link_name}") do
shell_out(alternatives_cmd, "--auto", new_resource.link_name)
end
end
action :refresh, description: "Refresh alternatives." do
converge_by("refreshing alternative #{new_resource.link_name}") do
shell_out(alternatives_cmd, "--refresh", new_resource.link_name)
end
end
action_class do
#
# @return [String] The appropriate alternatives command based on the platform
#
def alternatives_cmd
if debian?
"update-alternatives"
else
"alternatives"
end
end
#
# @return [Integer] The current path priority for the link_name alternative
#
def path_priority
# https://rubular.com/r/IcUlEU0mSNaMm3
escaped_path = Regexp.new(Regexp.escape("#{new_resource.path} - priority ") + "(.*)")
match = shell_out(alternatives_cmd, "--display", new_resource.link_name).stdout.match(escaped_path)
match.nil? ? nil : match[1].to_i
end
#
# @return [String] The current path for the link_name alternative
#
def current_path
# https://rubular.com/r/ylsuvzUtquRPqc
match = shell_out(alternatives_cmd, "--display", new_resource.link_name).stdout.match(/link currently points to (.*)/)
match[1]
end
#
# @return [Boolean] does the path exist for the link_name alternative
#
def path_exists?
# https://rubular.com/r/ogvDdq8h2IKRff
escaped_path = Regexp.new(Regexp.escape("#{new_resource.path} - priority"))
shell_out(alternatives_cmd, "--display", new_resource.link_name).stdout.match?(escaped_path)
end
end
end
end
end
|
