Support dnf module management - Fix #310

README.md

@@ -462,6 +462,56 @@ yum::install { 'package-name':
 
 Please note that resource name must be same as installed package name.
 
+### Manage DNF modules streams
+
+> When changing from one enabled stream to another one, the provider runs `dnf module switch-to <Stream>`, which replaces all installed profiles from the DNF module. Bear the consequences in mind.
+
+Enable default stream
+
+```puppet
+dnf_module_stream { '<Module>':
+  stream => default,
+}
+```
+
+Keep current enabled stream - if there isn't, enable default one
+
+```puppet
+dnf_module_stream { '<Module>':
+  stream => present,
+}
+```
+
+Enable a specific stream
+
+```puppet
+dnf_module_stream { '<Module>':
+  stream => <Stream name>,
+}
+```
+
+Disable stream (reset module)
+
+```puppet
+dnf_module_stream { '<Module>':
+  stream => absent,
+}
+```
+
+#### `dnf_module_stream` resource versus `dnfmodule` provider
+
+[DNF modules](https://dnf.readthedocs.io/en/latest/modularity.html) is a feature from `yum` successor, `dnf`, which allows easier and more robust selections of software versions and collections.
+
+As of Aug 22, 2023, [core Puppet `package` resource `dnfmodule` provider](https://www.puppet.com/docs/puppet/8/types/package.html#package-provider-dnfmodule) has some support for managing streams and profiles, but it has some issues:
+
+1. Setting stream is mandatory when (un)installing profiles - No way of just keeping currently enabled stream
+1. It only supports installing a single profile, despite the fact `dnf` supports multi-profile installations and there are use cases for that
+1. Managing two things - streams setting and profile (un)installation - in the same resource invocation is inherently messy
+
+One can fix 1 and 2, and add good docs to deal with 3. A compelling reason not to keep 1 and 3 is that a stream is a setting, not something one (un)installs. This makes it unsuitable for the `package` resource which, in principle, should only (un)install stuff.
+
+So, while one fix 2, this custom resource aims to fully and better replace `dnfmodule` provider stream support.
+
 ### Puppet tasks
 
 The module has a puppet task that allows to run `yum update` or `yum upgrade`.

REFERENCE.md

@@ -23,6 +23,10 @@
 * [`yum::post_transaction_action`](#yum--post_transaction_action): Creates post transaction configuratons for dnf or yum.
 * [`yum::versionlock`](#yum--versionlock): Locks package from updates.
 
+### Resource types
+
+* [`dnf_module_stream`](#dnf_module_stream): Manage DNF module streams
+
 ### Functions
 
 * [`yum::bool2num_hash_recursive`](#yum--bool2num_hash_recursive): This functions converts the Boolean values of a Hash to Integers, either '0' or '1'.  It does this recursively, decending as far as the langu
@@ -825,6 +829,77 @@ Epoch of the package if CentOS 8 mechanism is used.
 
 Default value: `0`
 
+## Resource types
+
+### <a name="dnf_module_stream"></a>`dnf_module_stream`
+
+This type allows Puppet to enable/disable streams via DNF modules
+
+#### Examples
+
+##### Enable MariaDB default stream
+
+```puppet
+dnf_module_stream { 'mariadb':
+  stream => default,
+}
+```
+
+##### Enable MariaDB 10.5 stream
+
+```puppet
+dnf_module_stream { 'mariadb':
+  stream => '10.5',
+}
+```
+
+##### Disable MariaDB streams
+
+```puppet
+dnf_module_stream { 'mariadb':
+  stream => absent,
+}
+```
+
+#### Properties
+
+The following properties are available in the `dnf_module_stream` type.
+
+##### `stream`
+
+Valid values: `present`, `default`, `absent`, `%r{.+}`
+
+      Module stream that should be enabled
+String - Specify stream
+present - Keep current enabled stream if any, otherwise enable default one
+default - Enable default stream
+absent - No stream (resets module)
+
+#### Parameters
+
+The following parameters are available in the `dnf_module_stream` type.
+
+* [`module`](#-dnf_module_stream--module)
+* [`provider`](#-dnf_module_stream--provider)
+* [`title`](#-dnf_module_stream--title)
+
+##### <a name="-dnf_module_stream--module"></a>`module`
+
+Valid values: `%r{.+}`
+
+DNF module to be managed
+
+##### <a name="-dnf_module_stream--provider"></a>`provider`
+
+The specific backend to use for this `dnf_module_stream` resource. You will seldom need to specify this --- Puppet will
+usually discover the appropriate provider for your platform.
+
+##### <a name="-dnf_module_stream--title"></a>`title`
+
+Valid values: `%r{.+}`
+
+Resource title
+
 ## Functions
 
 ### <a name="yum--bool2num_hash_recursive"></a>`yum::bool2num_hash_recursive`

lib/puppet/provider/dnf_module_stream/dnf_module_stream.rb

@@ -0,0 +1,100 @@
+# frozen_string_literal: true
+
+Puppet::Type.type(:dnf_module_stream).provide(:dnf_module_stream) do
+  desc 'Unique provider'
+
+  confine package_provider: 'dnf'
+
+  commands dnf: 'dnf'
+
+  # Converts plain output from 'dnf module list <Module>' to an array formatted as:
+  # {
+  #   default_stream: "<Default stream> (if there's one)",
+  #   enabled_stream: "<Enabled stream> (if there's one)",
+  #   available_streams: ["<Stream>", "<Stream>", ...,]
+  # }
+  def dnf_output_2_hash(dnf_output)
+    module_hash = { available_streams: [] }
+    dnf_output.lines.each do |line|
+      line.chomp!
+      break if line.empty?
+
+      # @stream_start and @stream_length: chunk of dnf output line with stream info
+      # Determined in elsif block below from dnf output header
+      if !@stream_start.nil?
+        # Stream string is '<Stream>', '<Stream> [d][e]', or the like
+        stream_string = line[@stream_start, @stream_length].rstrip
+        stream = stream_string.split[0]
+        module_hash[:default_stream] = stream if stream_string.include?('[d]')
+        module_hash[:enabled_stream] = stream if stream_string.include?('[e]')
+        module_hash[:available_streams] << stream
+      elsif line.split[0] == 'Name'
+        # 'dnf module list' output header is 'Name<Spaces>Stream<Spaces>Profiles<Spaces>...'
+        # Each field has same position of data that follows
+        @stream_start = line[%r{Name\s+}].length
+        @stream_length = line[%r{Stream\s+}].length
+      end
+    end
+    module_hash
+  end
+
+  # Gets module default, enabled and available streams
+  # Output formatted by function dnf_output_2_hash
+  def streams_state(module_name)
+    # This function can be called multiple times in the same resource call
+    return unless @streams_current_state.nil?
+
+    dnf_output = dnf('-q', 'module', 'list', module_name)
+  rescue Puppet::ExecutionFailure
+    # Assumes any execution error happens because module doesn't exist
+    raise ArgumentError, "Module \"#{module_name}\" not found"
+  else
+    @streams_current_state = dnf_output_2_hash(dnf_output)
+  end
+
+  def disable_stream(module_name)
+    dnf('-y', 'module', 'reset', module_name)
+  end
+
+  def enable_stream(module_name, target_stream)
+    action = @streams_current_state.key?(:enabled_stream) ? 'switch-to' : 'enable'
+    dnf('-y', 'module', action, "#{module_name}:#{target_stream}")
+  end
+
+  def stream
+    streams_state(resource[:module])
+    case resource[:stream]
+    when :absent
+      # Act if any stream is enabled
+      @streams_current_state.key?(:enabled_stream) ? @streams_current_state[:enabled_stream] : :absent
+    when :default
+      # Act if default stream isn't enabled
+      # Specified stream = :default requires an existing default stream
+      raise ArgumentError, "No default stream to enable in module \"#{resource[:module]}\"" unless
+        @streams_current_state.key?(:default_stream)
+
+      @streams_current_state[:enabled_stream] == @streams_current_state[:default_stream] ? :default : @streams_current_state[:enabled_stream]
+    when :present
+      # Act if no stream is enabled
+      # Specified stream = :default requires an existing default or enabled stream
+      raise ArgumentError, "No default stream to enable in module \"#{resource[:module]}\"" unless
+        @streams_current_state.key?(:default_stream) || @streams_current_state.key?(:enabled_stream)
+
+      @streams_current_state.key?(:enabled_stream) ? :present : :absent
+    else
+      # Act if specified stream isn't enabled
+      @streams_current_state[:enabled_stream]
+    end
+  end
+
+  def stream=(target_stream)
+    case target_stream
+    when :absent
+      disable_stream(resource[:module])
+    when :default, :present
+      enable_stream(resource[:module], @streams_current_state[:default_stream])
+    else
+      enable_stream(resource[:module], target_stream)
+    end
+  end
+end

lib/puppet/type/dnf_module_stream.rb

@@ -0,0 +1,46 @@
+# frozen_string_literal: true
+
+Puppet::Type.newtype(:dnf_module_stream) do
+  @doc = <<-TYPE_DOC
+    @summary Manage DNF module streams
+    @example Enable MariaDB default stream
+      dnf_module_stream { 'mariadb':
+        stream => default,
+      }
+    @example Enable MariaDB 10.5 stream
+      dnf_module_stream { 'mariadb':
+        stream => '10.5',
+      }
+    @example Disable MariaDB streams
+      dnf_module_stream { 'mariadb':
+        stream => absent,
+      }
+    @param module
+      Module to be managed - Defaults to title
+    @param stream
+      Module stream to be enabled
+
+    This type allows Puppet to enable/disable streams via DNF modules
+  TYPE_DOC
+
+  newparam(:title, namevar: true) do
+    desc 'Resource title'
+    newvalues(%r{.+})
+  end
+
+  newparam(:module) do
+    desc 'DNF module to be managed'
+    newvalues(%r{.+})
+  end
+
+  newproperty(:stream) do
+    desc <<-EOS
+      Module stream that should be enabled
+        String - Specify stream
+        present - Keep current enabled stream if any, otherwise enable default one
+        default - Enable default stream
+        absent - No stream (resets module)
+    EOS
+    newvalues(:present, :default, :absent, %r{.+})
+  end
+end

spec/acceptance/post_transaction_actions_spec.rb

@@ -4,6 +4,15 @@
 
 describe 'yum::post_transaction_action define' do
   context 'simple parameters' do
+    let(:pre_condition) do
+      "
+        package{ 'vim-enhanced-absent':
+          name    => 'vim-enhanced',
+          ensure  => 'absent',
+        }
+      "
+    end
+
     # Using puppet_apply as a helper
     it 'must work idempotently with no errors' do
       pp = <<-EOS

spec/unit/puppet/provider/dnf_module_stream/dnf_module_stream_spec.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe 'the dnf_module_stream provider' do
+  it 'loads' do
+    expect(Puppet::Type.type(:dnf_module_stream).provide(:dnf_module_stream)).not_to be_nil
+  end
+end

spec/unit/puppet/type/dnf_module_stream_spec.rb

@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+dnf_module_stream = Puppet::Type.type(:dnf_module_stream)
+RSpec.describe 'the dnf_module_stream type' do
+  it 'loads' do
+    expect(dnf_module_stream).not_to be_nil
+  end
+
+  it 'has parameter module' do
+    expect(dnf_module_stream.parameters).to be_include(:module)
+  end
+
+  it 'has property stream' do
+    expect(dnf_module_stream.properties.map(&:name)).to be_include(:stream)
+  end
+end