Ability to reset settings to default value and delete newly added keys

lib/vmdb/settings.rb

@@ -7,6 +7,7 @@
 module Vmdb
   class Settings
     extend Vmdb::SettingsWalker::ClassMethods
+    include Vmdb::Logging
 
     class ConfigurationInvalid < StandardError
       attr_accessor :errors
@@ -21,6 +22,11 @@ def initialize(errors)
     PASSWORD_FIELDS = Vmdb::SettingsWalker::PASSWORD_FIELDS
     DUMP_LOG_FILE   = Rails.root.join("log/last_settings.txt").freeze
 
+    # RESET_COMMAND remove record for selected key and specific resource
+    # RESET_ALL_COMMAND remove all records for selected key and all resources
+    MAGIC_VALUES = [RESET_COMMAND      = "<<reset>>".freeze,
+                    RESET_ALL_COMMAND  = "<<reset_all>>".freeze].freeze
+
     cattr_accessor :last_loaded
 
     def self.init
@@ -62,8 +68,9 @@ def self.valid?
 
     def self.save!(resource, hash)
       new_settings = build_without_local(resource).load!.merge!(hash).to_hash
+      settings_to_validate = remove_magic_values(new_settings.deep_clone)
 
-      valid, errors = validate(new_settings)
+      valid, errors = validate(settings_to_validate)
       raise ConfigurationInvalid.new(errors) unless valid # rubocop:disable Style/RaiseArgs
 
       hash_for_parent = parent_settings_without_local(resource).load!.to_hash
@@ -188,6 +195,7 @@ def self.apply_settings_changes(resource, deltas)
 
         deltas.each do |delta|
           record = index.delete(delta[:key])
+          next if process_magic_value(resource, delta)
           if record
             record.update_attributes!(delta)
           else
@@ -198,5 +206,33 @@ def self.apply_settings_changes(resource, deltas)
       end
     end
     private_class_method :apply_settings_changes
+
+    def self.process_magic_value(resource, delta)
+      return false unless MAGIC_VALUES.include?(delta[:value])
+      case delta[:value]
+      when RESET_COMMAND
+        _log.info("resetting #{delta[:key]} on #{resource.class} id:#{resource.id}")
+        resource.settings_changes.where("key LIKE ?", "#{delta[:key]}%").destroy_all
+      when RESET_ALL_COMMAND
+        _log.info("resetting #{delta[:key]} to default for all resorces")
+        SettingsChange.where("key LIKE ?", "#{delta[:key]}%").destroy_all
+      end
+      true
+    end
+    private_class_method :process_magic_value
+
+    def self.walk_hash(hash, &block)
+      hash.each do |key, value|
+        yield key, value, hash
+        walk_hash(value, &block) if value&.class == Hash
+      end
+    end
+    private_class_method :walk_hash
+
+    def self.remove_magic_values(hash)
+      walk_hash(hash) { |key, value, owner| owner.delete(key) if MAGIC_VALUES.include?(value) }
+      hash
+    end
+    private_class_method :remove_magic_values
   end
 end

spec/lib/vmdb/settings_spec.rb

@@ -265,6 +265,85 @@
       miq_server.zone.reload
       expect(miq_server.zone.settings_changes.count).to eq 0
     end
+
+    context "deleting entries" do
+      let(:server_value) { 1 }
+      let(:zone_value)   { 2 }
+
+      let(:reset)     { ::Vmdb::Settings::RESET_COMMAND }
+      let(:reset_all) { ::Vmdb::Settings::RESET_ALL_COMMAND }
+
+      let(:second_server) { FactoryGirl.create(:miq_server, :zone => miq_server.zone) }
+
+      before do
+        MiqRegion.seed
+
+        described_class.save!(miq_server, :api => {:token_ttl => server_value}, :session => {:timeout => server_value})
+        described_class.save!(miq_server, :api => {:new_key => "new value"})
+        described_class.save!(second_server, :api => {:token_ttl => server_value}, :session => {:timeout => server_value})
+
+        described_class.save!(miq_server.zone, :api => {:token_ttl => zone_value}, :session => {:timeout => zone_value})
+        described_class.save!(miq_server, :array => [:element1 => 1, :element2 => 2])
+        expect(SettingsChange.count).to eq 8
+      end
+
+      context "magic value <<reset>>" do
+        it "deletes key-value for specific key for the resource if specified on leaf level" do
+          described_class.save!(miq_server, :api => {:token_ttl => reset})
+
+          expect(SettingsChange.count).to eq 7
+          expect(miq_server.settings_changes.find_by(:key => "/api/token_ttl")).to be nil
+          expect(Vmdb::Settings.for_resource(miq_server).api.new_key).to eq "new value"
+          expect(Vmdb::Settings.for_resource(second_server).api.token_ttl).to eq server_value
+        end
+
+        it "deletes current node and all sub-nodes for the resource if specified on node level" do
+          described_class.save!(miq_server, :api => reset)
+
+          expect(SettingsChange.count).to eq 6
+          expect(miq_server.settings_changes.where("key LIKE ?", "/api%").count).to eq 0
+          expect(Vmdb::Settings.for_resource(miq_server).api.new_key).to eq nil
+          expect(Vmdb::Settings.for_resource(second_server).api.token_ttl).to eq server_value
+        end
+
+        it "deletes new key-value settings not present in defaul yaml" do
+          described_class.save!(miq_server, :api => {:new_key => reset})
+          expect(Vmdb::Settings.for_resource(miq_server).api.new_key).to eq nil
+        end
+
+        it "deletes array" do
+          described_class.save!(miq_server, :array => reset)
+          expect(Vmdb::Settings.for_resource(miq_server).array).to be nil
+        end
+
+        it "passes validation" do
+          described_class.save!(miq_server, :session => {:timeout => reset})
+          expect(Vmdb::Settings.for_resource(miq_server).session.timeout).to eq zone_value
+        end
+      end
+
+      context "magic value <<reset_all>>" do
+        it "deletes all key-value for specific key for all resource if specified on leaf levelher" do
+          described_class.save!(miq_server, :api => {:token_ttl => reset_all})
+
+          expect(SettingsChange.where("key LIKE ?", "/api/token_ttl").count).to eq 0
+          expect(SettingsChange.where("key LIKE ?", "/api%").count).to eq 1
+          expect(SettingsChange.where("key LIKE ?", "/session%").count).to eq 3
+        end
+
+        it "deletes specific node and all sub-nodes for all resources if specified on node level" do
+          described_class.save!(miq_server, :api => reset_all)
+
+          expect(SettingsChange.where("key LIKE ?", "/api%").count).to eq 0
+          expect(SettingsChange.where("key LIKE ?", "/session%").count).to eq 3
+        end
+
+        it "passes validation" do
+          described_class.save!(miq_server, :session => {:timeout => reset_all})
+          expect(SettingsChange.where("key LIKE ?", "/session%").count).to eq 0
+        end
+      end
+    end
   end
 
   describe "save_yaml!" do