(GH-213) Gather facts using the Sidecar

Previously the facts where evaluated only within the Editor Service process
however this meant the workspace couldn't be injected.  This commit adds a new
action to the Sidecar process to evaluate the facts. The Sidecar has the
required monkey patches to inject the workspace into the fact search
directories.

This commit also adds tests and fixtures to ensure that custom and external
facts can be resolved.

Author: glennsarti

lib/puppet-languageserver-sidecar/facter_helper.rb

@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+module PuppetLanguageServerSidecar
+  module FacterHelper
+    def self.current_environment
+      begin
+        env = Puppet.lookup(:environments).get!(Puppet.settings[:environment])
+        return env unless env.nil?
+      rescue Puppet::Environments::EnvironmentNotFound
+        PuppetLanguageServerSidecar.log_message(:warning, "[FacterHelper::current_environment] Unable to load environment #{Puppet.settings[:environment]}")
+      rescue StandardError => e
+        PuppetLanguageServerSidecar.log_message(:warning, "[FacterHelper::current_environment] Error loading environment #{Puppet.settings[:environment]}: #{e}")
+      end
+      Puppet.lookup(:current_environment)
+    end
+
+    def self.retrieve_facts(_cache, _options = {})
+      require 'puppet/indirector/facts/facter'
+
+      PuppetLanguageServerSidecar.log_message(:debug, '[FacterHelper::retrieve_facts] Starting')
+      facts = PuppetLanguageServer::Sidecar::Protocol::Facts.new
+      begin
+        req = Puppet::Indirector::Request.new(:facts, :find, 'language_server', nil, environment: current_environment)
+        result = Puppet::Node::Facts::Facter.new.find(req)
+        facts.from_h!(result.values)
+      rescue StandardError => e
+        PuppetLanguageServerSidecar.log_message(:error, "[FacterHelper::_load_facts] Error loading facts #{e.message} #{e.backtrace}")
+      rescue LoadError => e
+        PuppetLanguageServerSidecar.log_message(:error, "[FacterHelper::_load_facts] Error loading facts (LoadError) #{e.message} #{e.backtrace}")
+      end
+
+      PuppetLanguageServerSidecar.log_message(:debug, "[FacterHelper::retrieve_facts] Finished loading #{facts.keys.count} facts")
+      facts
+    end
+  end
+end

lib/puppet-languageserver-sidecar/puppet_modulepath_monkey_patches.rb

@@ -122,3 +122,21 @@ def modulepath
     result
   end
 end
+
+# Inject the workspace into the facter search paths
+require 'puppet/indirector/facts/facter'
+class Puppet::Node::Facts::Facter # rubocop:disable Style/ClassAndModuleChildren
+  class << self
+    alias_method :original_setup_search_paths, :setup_search_paths
+    def setup_search_paths(request)
+      result = original_setup_search_paths(request)
+      return result unless PuppetLanguageServerSidecar::Workspace.has_module_metadata?
+
+      additional_dirs = %w[lib plugins].map { |path| File.join(PuppetLanguageServerSidecar::Workspace.root_path, path, 'facter') }
+                                       .select { |path| FileTest.directory?(path) }
+
+      return result if additional_dirs.empty?
+      Facter.search(*additional_dirs)
+    end
+  end
+end

lib/puppet-languageserver/sidecar_protocol.rb

@@ -520,6 +520,27 @@ def list_for_object_class(klass)
           raise "Unknown object class #{klass.name}"
         end
       end
+
+      class Facts < Hash
+        include Base
+
+        def from_h!(value)
+          value.keys.each { |key| self[key] = value[key] }
+          self
+        end
+
+        def to_json(*options)
+          ::JSON.generate(to_h, options)
+        end
+
+        def from_json!(json_string)
+          obj = ::JSON.parse(json_string)
+          obj.each do |key, value|
+            self[key] = value
+          end
+          self
+        end
+      end
     end
   end
 end

lib/puppet_languageserver_sidecar.rb

@@ -80,6 +80,7 @@ def self.require_gems(options)
       puppet_parser_helper
       sidecar_protocol_extensions
       workspace
+      facter_helper
     ]
 
     # Load files based on feature flags
@@ -117,6 +118,7 @@ def self.require_gems(options)
     workspace_datatypes
     workspace_functions
     workspace_types
+    facts
   ].freeze
 
   class CommandLineParser
@@ -389,6 +391,14 @@ def self.execute(options)
         PuppetLanguageServerSidecar::PuppetHelper.retrieve_types(null_cache)
       end
 
+    when 'facts'
+      # Can't cache for facts
+      cache = PuppetLanguageServerSidecar::Cache::Null.new
+      # Inject the workspace etc. if present
+      injected = inject_workspace_as_module
+      inject_workspace_as_environment unless injected
+      PuppetLanguageServerSidecar::FacterHelper.retrieve_facts(cache)
+
     else
       log_message(:error, "Unknown action #{options[:action]}. Expected one of #{ACTION_LIST}")
     end

spec/languageserver-sidecar/fixtures/real_agent/cache/facts.d/.gitkeep

@@ -0,0 +1,5 @@
+Facter.add('fixture_agent_custom_fact') do
+  setcode do
+    'fixture_agent_custom_fact_value'
+  end
+end

spec/languageserver-sidecar/fixtures/real_agent/cache/lib/facter/.gitkeep

@@ -0,0 +1,2 @@
+---
+fixture_environment_external_fact: "fixture_environment_external_fact_value"

spec/languageserver-sidecar/fixtures/real_agent/cache/lib/facter/fixture_agent_custom_fact.rb

@@ -0,0 +1,5 @@
+Facter.add('fixture_environment_custom_fact') do
+  setcode do
+    'fixture_environment_custom_fact_value'
+  end
+end

spec/languageserver-sidecar/fixtures/valid_environment_workspace/site/private/facts.d/fixture_environment_external_fact.yaml

@@ -0,0 +1,2 @@
+---
+fixture_module_external_fact: "fixture_module_external_fact_value"