Add Fluentd::Setting::Config#delete_element

Signed-off-by: Kenji Okimoto <okimoto@clear-code.com>

app/models/fluentd/setting/config.rb

@@ -63,6 +63,41 @@ class Fluentd
         hash
       end
 
+      def delete_element(name, arg, element)
+        if name == "label"
+          label_section = fl_config.elements(name: name, arg: arg).first
+          original_size = label_section.elements.size
+          remaining_elements = label_section.elements.reject do |e|
+            element == e
+          end
+          if remaining_elements.empty?
+            remaining_elements = fl_config.elements.reject do |e|
+              label_section == e
+            end
+            fl_config.elements = remaining_elements
+            return element
+          else
+            label_section.elements = remaining_elements
+            if original_size == label_section.elements.size
+              return nil
+            else
+              return element
+            end
+          end
+        else
+          original_size = fl_config.elements.size
+          remaining_elements = fl_config.elements.reject do |e|
+            element == e
+          end
+          fl_config.elements = remaining_elements
+          if original_size == fl_config.elements.size
+            return nil
+          else
+            return element
+          end
+        end
+      end
+
       def write_to_file
         return unless Fluentd.instance
         Fluentd.instance.agent.config_write formatted

test/models/fluentd/setting/config_test.rb

@@ -0,0 +1,98 @@
+require "test_helper"
+
+class FluentdConfigTest < ActiveSupport::TestCase
+  def create_config(fixture_name)
+    ::Fluentd::Setting::Config.new(fixture_path(fixture_name))
+  end
+
+  sub_test_case "#delete_element" do
+    test "delete a source" do
+      config = create_config("config/simple.conf")
+      element = config.elements(name: "source").first
+      config.delete_element("source", nil, element)
+      assert_equal(config.formatted.strip, <<CONFIG.chomp)
+<filter dummy>
+  @type stdout
+</filter>
+
+<match dummy>
+  @type stdout
+</match>
+CONFIG
+    end
+
+    test "delete a filter" do
+      config = create_config("config/simple.conf")
+      element = config.elements(name: "filter").first
+      config.delete_element("filter", nil, element)
+      assert_equal(config.formatted.strip, <<CONFIG.chomp)
+<source>
+  @type dummy
+  tag dummy
+</source>
+
+<match dummy>
+  @type stdout
+</match>
+CONFIG
+    end
+
+    test "delete a match" do
+      config = create_config("config/simple.conf")
+      element = config.elements(name: "match").first
+      config.delete_element("match", nil, element)
+      assert_equal(config.formatted.strip, <<CONFIG.chomp)
+<source>
+  @type dummy
+  tag dummy
+</source>
+
+<filter dummy>
+  @type stdout
+</filter>
+CONFIG
+    end
+
+    test "delete all elements under the label" do
+      config = create_config("config/multi-label.conf")
+      input = config.elements(name: "label", arg: "@INPUT").first
+      input.elements.each do |element|
+        config.delete_element("label", "@INPUT", element)
+      end
+      assert_equal(config.formatted.strip, <<CONFIG.chomp)
+<source>
+  @type dummy
+  tag dummy1
+  @label @INPUT
+</source>
+
+<source>
+  @type dummy
+  tag dummy2
+  @label @INPUT
+</source>
+
+<label @MAIN>
+  <filter dummy1>
+    @type stdout
+  </filter>
+  <filter dummy2>
+    @type stdout
+  </filter>
+  <match dummy1>
+    @type stdout
+  </match>
+  <match dummy2>
+    @type stdout
+  </match>
+</label>
+CONFIG
+    end
+
+    test "cannot delete specified element" do
+      config = create_config("config/simple.conf")
+      element = ::Fluent::Config::Element.new("source", nil, { :@type => "dummy", :tag => "dummy" }, [])
+      assert_nil(config.delete_element("source", nil, element))
+    end
+  end
+end