Merge pull request #126 from DavidS/pdk-1185-multi-device-providers

(PDK-1185) Implement allowances for device-specific providers

Author: da-ar

README.md

@@ -180,6 +180,10 @@ The provider needs to specify the `remote_resource` feature to enable the second
 
 After this, `puppet device` will be able to use the new provider, and supply it (through the device class) with the URL specified in the [`device.conf`](https://puppet.com/docs/puppet/5.3/config_file_device.html).
 
+#### Device-specific providers
+
+To allow modules to deal with different backends independently of each other, the Resource API also implements a mechanism to use different API providers side-by-side. For a given device type (see above), the Resource API will first try to load a `Puppet::Provider::TypeName::DeviceType` class from `lib/puppet/provider/type_name/device_type.rb`, before falling back to the regular provider at `Puppet::Provider::TypeName::TypeName`.
+
 ### Further Reading
 
 The [Resource API](https://github.com/puppetlabs/puppet-specifications/blob/master/language/resource-api/README.md) describes details of all the capabilities of this gem.

lib/puppet/resource_api.rb

@@ -4,6 +4,7 @@
 require 'puppet/resource_api/type_definition'
 require 'puppet/resource_api/version'
 require 'puppet/type'
+require 'puppet/util/network_device'
 
 module Puppet::ResourceApi
   @warning_count = 0
@@ -54,7 +55,8 @@ def register_type(definition)
 
       # Keeps a copy of the provider around. Weird naming to avoid clashes with puppet's own `provider` member
       define_singleton_method(:my_provider) do
-        @my_provider ||= Puppet::ResourceApi.load_provider(definition[:name]).new
+        @my_provider ||= Hash.new { |hash, key| hash[key] = Puppet::ResourceApi.load_provider(definition[:name]).new }
+        @my_provider[Puppet::Util::NetworkDevice.current.class]
       end
 
       # make the provider available in the instance's namespace
@@ -514,14 +516,48 @@ def self.parse_title_patterns(patterns)
   def load_provider(type_name)
     class_name = class_name_from_type_name(type_name)
     type_name_sym = type_name.to_sym
+    device_name = if Puppet::Util::NetworkDevice.current.nil?
+                    nil
+                  else
+                    # extract the device type from the currently loaded device's class
+                    Puppet::Util::NetworkDevice.current.class.name.split('::')[-2].downcase
+                  end
+    device_class_name = class_name_from_type_name(device_name)
+
+    if device_name
+      device_name_sym = device_name.to_sym if device_name
+      load_device_provider(class_name, type_name_sym, device_class_name, device_name_sym)
+    else
+      load_default_provider(class_name, type_name_sym)
+    end
+  rescue NameError
+    if device_name # line too long # rubocop:disable Style/GuardClause
+      raise Puppet::DevError, "Found neither the device-specific provider class Puppet::Provider::#{class_name}::#{device_class_name} in puppet/provider/#{type_name}/#{device_name}"\
+      " nor the generic provider class Puppet::Provider::#{class_name}::#{class_name} in puppet/provider/#{type_name}/#{type_name}"
+    else
+      raise Puppet::DevError, "provider class Puppet::Provider::#{class_name}::#{class_name} not found in puppet/provider/#{type_name}/#{type_name}"
+    end
+  end
+  module_function :load_provider # rubocop:disable Style/AccessModifierDeclarations
 
+  def load_default_provider(class_name, type_name_sym)
     # loads the "puppet/provider/#{type_name}/#{type_name}" file through puppet
     Puppet::Type.type(type_name_sym).provider(type_name_sym)
     Puppet::Provider.const_get(class_name).const_get(class_name)
-  rescue NameError
-    raise Puppet::DevError, "class #{class_name} not found in puppet/provider/#{type_name}/#{type_name}"
   end
-  module_function :load_provider # rubocop:disable Style/AccessModifierDeclarations
+  module_function :load_default_provider # rubocop:disable Style/AccessModifierDeclarations
+
+  def load_device_provider(class_name, type_name_sym, device_class_name, device_name_sym)
+    # loads the "puppet/provider/#{type_name}/#{device_name}" file through puppet
+    Puppet::Type.type(type_name_sym).provider(device_name_sym)
+    provider_module = Puppet::Provider.const_get(class_name)
+    if provider_module.const_defined?(device_class_name)
+      provider_module.const_get(device_class_name)
+    else
+      load_default_provider(class_name, type_name_sym)
+    end
+  end
+  module_function :load_device_provider # rubocop:disable Style/AccessModifierDeclarations
 
   def self.class_name_from_type_name(type_name)
     type_name.to_s.split('_').map(&:capitalize).join

spec/acceptance/multi_device_spec.rb

@@ -0,0 +1,92 @@
+require 'open3'
+require 'puppet/version'
+require 'spec_helper'
+require 'tempfile'
+
+RSpec.describe 'exercising a type with device-specific providers' do
+  let(:common_args) { '--verbose --trace --strict=error --modulepath spec/fixtures' }
+
+  before(:all) do
+    FileUtils.mkdir_p(File.expand_path('~/.puppetlabs/opt/puppet/cache/devices/some_node/state'))
+    FileUtils.mkdir_p(File.expand_path('~/.puppetlabs/opt/puppet/cache/devices/other_node/state'))
+  end
+
+  describe 'using `puppet device`' do
+    let(:common_args) { super() + " --deviceconfig #{device_conf.path} --target some_node --target other_node" }
+    let(:device_conf) { Tempfile.new('device.conf') }
+    let(:device_conf_content) do
+      <<DEVICE_CONF
+[some_node]
+type some_device
+url  file:///etc/credentials.txt
+[other_node]
+type other_device
+url  file:///etc/credentials.txt
+DEVICE_CONF
+    end
+
+    def is_device_apply_supported?
+      Gem::Version.new(Puppet::PUPPETVERSION) >= Gem::Version.new('5.3.6') && Gem::Version.new(Puppet::PUPPETVERSION) != Gem::Version.new('5.4.0')
+    end
+
+    before(:each) do
+      skip "No device --apply in puppet before v5.3.6 nor in v5.4.0 (v#{Puppet::PUPPETVERSION} is installed)" unless is_device_apply_supported?
+      device_conf.write(device_conf_content)
+      device_conf.close
+    end
+
+    after(:each) do
+      device_conf.unlink
+    end
+
+    it 'applies a catalog successfully' do
+      pending "can't really test this without a puppetserver; when initially implementing this, it was tested using a hacked `puppet device` command allowing multiple --target params"
+
+      # diff --git a/lib/puppet/application/device.rb b/lib/puppet/application/device.rb
+      # index 5e7a5cd473..2d39527b47 100644
+      # --- a/lib/puppet/application/device.rb
+      # +++ b/lib/puppet/application/device.rb
+      # @@ -70,7 +70,8 @@ class Puppet::Application::Device < Puppet::Application
+      #    end
+
+      #    option("--target DEVICE", "-t") do |arg|
+      # -    options[:target] = arg.to_s
+      # +    options[:target] ||= []
+      # +    options[:target] << arg.to_s
+      #    end
+
+      #    def summary
+      # @@ -232,7 +233,7 @@ Licensed under the Apache 2.0 License
+      #        require 'puppet/util/network_device/config'
+      #        devices = Puppet::Util::NetworkDevice::Config.devices.dup
+      #        if options[:target]
+      # -        devices.select! { |key, value| key == options[:target] }
+      # +        devices.select! { |key, value| options[:target].include? key }
+      #        end
+      #        if devices.empty?
+      #          if options[:target]
+
+      # david@davids:~/git/puppet-resource_api$ bundle exec puppet device --verbose --trace --strict=error --modulepath spec/fixtures \
+      #       --target some_node --target other_node --resource multi_device multi_device multi_device
+      # ["multi_device", "multi_device", "multi_device"]
+      # Info: retrieving resource: multi_device from some_node at file:///etc/credentials.txt
+      # multi_device { 'multi_device':
+      #   ensure => 'absent',
+      # }
+      # ["multi_device"]
+      # Info: retrieving resource: multi_device from other_node at file:///etc/credentials.txt
+
+      # david@davids:~/git/puppet-resource_api$
+
+      Tempfile.create('apply_success') do |f|
+        f.write 'multi_device { "foo": }'
+        f.close
+
+        stdout_str, _status = Open3.capture2e("puppet device #{common_args} --apply #{f.path}")
+        expect(stdout_str).to match %r{Compiled catalog for some_node}
+        expect(stdout_str).to match %r{Compiled catalog for other_node}
+        expect(stdout_str).not_to match %r{Error:}
+      end
+    end
+  end
+end

spec/fixtures/test_module/lib/puppet/provider/multi_device/multi_device.rb

@@ -0,0 +1,21 @@
+require 'puppet/resource_api/simple_provider'
+
+# Implementation for the multi_device type using the Resource API.
+# default provider class
+class Puppet::Provider::MultiDevice::MultiDevice < Puppet::ResourceApi::SimpleProvider
+  def get(_context)
+    []
+  end
+
+  def create(context, name, should)
+    context.notice("Creating '#{name}' with #{should.inspect}")
+  end
+
+  def update(context, name, should)
+    context.notice("Updating '#{name}' with #{should.inspect}")
+  end
+
+  def delete(context, name)
+    context.notice("Deleting '#{name}'")
+  end
+end

spec/fixtures/test_module/lib/puppet/provider/multi_device/other_device.rb

@@ -0,0 +1,21 @@
+require 'puppet/resource_api/simple_provider'
+
+# Implementation for the multi_device type using the Resource API.
+# device-specific class for `other_device`
+class Puppet::Provider::MultiDevice::OtherDevice < Puppet::ResourceApi::SimpleProvider
+  def get(_context)
+    []
+  end
+
+  def create(context, name, should)
+    context.notice("Creating '#{name}' with #{should.inspect}")
+  end
+
+  def update(context, name, should)
+    context.notice("Updating '#{name}' with #{should.inspect}")
+  end
+
+  def delete(context, name)
+    context.notice("Deleting '#{name}'")
+  end
+end

spec/fixtures/test_module/lib/puppet/provider/multi_device/some_device.rb

@@ -0,0 +1,21 @@
+require 'puppet/resource_api/simple_provider'
+
+# Implementation for the multi_device type using the Resource API.
+# device-specific class for `some_device`
+class Puppet::Provider::MultiDevice::SomeDevice < Puppet::ResourceApi::SimpleProvider
+  def get(_context)
+    []
+  end
+
+  def create(context, name, should)
+    context.notice("Creating '#{name}' with #{should.inspect}")
+  end
+
+  def update(context, name, should)
+    context.notice("Updating '#{name}' with #{should.inspect}")
+  end
+
+  def delete(context, name)
+    context.notice("Deleting '#{name}'")
+  end
+end

spec/fixtures/test_module/lib/puppet/type/multi_device.rb

@@ -0,0 +1,21 @@
+require 'puppet/resource_api'
+
+Puppet::ResourceApi.register_type(
+  name: 'multi_device',
+  docs: <<-EOS,
+      This type provides Puppet with the capabilities to manage ...
+    EOS
+  features: [ 'remote_resource' ],
+  attributes:   {
+    ensure:      {
+      type:    'Enum[present, absent]',
+      desc:    'Whether this resource should be present or absent on the target system.',
+      default: 'present',
+    },
+    name:        {
+      type:      'String',
+      desc:      'The name of the resource you want to manage.',
+      behaviour: :namevar,
+    },
+  },
+)

spec/fixtures/test_module/lib/puppet/util/network_device/other_device/device.rb

@@ -0,0 +1,10 @@
+require 'puppet/util/network_device/simple/device'
+
+module Puppet::Util::NetworkDevice::Other_device # rubocop:disable Style/ClassAndModuleCamelCase
+  # A simple test device returning hardcoded facts
+  class Device < Puppet::Util::NetworkDevice::Simple::Device
+    def facts
+      { 'foo' => 'bar' }
+    end
+  end
+end

spec/fixtures/test_module/lib/puppet/util/network_device/some_device/device.rb

@@ -0,0 +1,10 @@
+require 'puppet/util/network_device/simple/device'
+
+module Puppet::Util::NetworkDevice::Some_device # rubocop:disable Style/ClassAndModuleCamelCase
+  # A simple test device returning hardcoded facts
+  class Device < Puppet::Util::NetworkDevice::Simple::Device
+    def facts
+      { 'foo' => 'bar' }
+    end
+  end
+end

spec/fixtures/test_module/spec/unit/puppet/provider/multi_device/multi_device_spec.rb

@@ -0,0 +1,49 @@
+require 'spec_helper'
+
+ensure_module_defined('Puppet::Provider::MultiDevice')
+require 'puppet/provider/multi_device/multi_device'
+
+RSpec.describe Puppet::Provider::MultiDevice::MultiDevice do
+  subject(:provider) { described_class.new }
+
+  let(:context) { instance_double('Puppet::ResourceApi::BaseContext', 'context') }
+
+  describe '#get' do
+    it 'processes resources' do
+      expect(provider.get(context)).to eq [
+        {
+          name: 'foo',
+          ensure: 'present',
+        },
+        {
+          name: 'bar',
+          ensure: 'present',
+        },
+      ]
+    end
+  end
+
+  describe 'create(context, name, should)' do
+    it 'creates the resource' do
+      expect(context).to receive(:notice).with(%r{\ACreating 'a'})
+
+      provider.create(context, 'a', name: 'a', ensure: 'present')
+    end
+  end
+
+  describe 'update(context, name, should)' do
+    it 'updates the resource' do
+      expect(context).to receive(:notice).with(%r{\AUpdating 'foo'})
+
+      provider.update(context, 'foo', name: 'foo', ensure: 'present')
+    end
+  end
+
+  describe 'delete(context, name, should)' do
+    it 'deletes the resource' do
+      expect(context).to receive(:notice).with(%r{\ADeleting 'foo'})
+
+      provider.delete(context, 'foo')
+    end
+  end
+end