Add Fluentd::Agent::Common#parse_config

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

app/models/fluentd/agent/common.rb

@@ -18,6 +18,8 @@
 #   - https://github.com/treasure-data/omnibus-td-agent/blob/master/templates/etc/systemd/td-agent.service.erb#L14
 #   fluentd: /etc/fluent/fluent.conf (created by fluentd -s)
 
+require "strscan"
+
 class Fluentd
   class Agent
     module Common
@@ -142,6 +144,39 @@ class Fluentd
           FileUtils.rm(file) if File.exist? file
         end
       end
+
+      def parse_config(config_content)
+        scanner = StringScanner.new(config_content)
+        contents = Hash.new {|h, k| h[k] = [] }
+        until scanner.eos? do
+          started = scanner.pos
+          header = scanner.scan_until(/^<(source|filter|match|label)/)
+          section_type = scanner[1]
+          break unless header
+          case section_type
+          when "source", "filter", "match"
+            current_source = header + scanner.scan_until(%r{^</(?:source|filter|match)>})
+            contents[section_type] << { pos: started, content: current_source.strip }
+          when "label"
+            scanner.scan(/ ([^\s]+?)>/)
+            label = scanner[1]
+            sections = Hash.new {|h, k| h[k] = [] }
+            loop do
+              break if scanner.match?(%r{\s+?</label>})
+              section_pos = scanner.pos
+              section_header = scanner.scan_until(/^\s*<(filter|match)/)
+              section_type = scanner[1]
+              section_source = section_header + scanner.scan_until(%r{^\s*</(?:filter|match)>})
+              sections[section_type] << { pos: section_pos ,content: section_source.sub(/\n/, "")}
+            end
+            scanner.scan_until(%r{^</label>})
+            contents["label:#{label}"] << { pos: started, sections: sections }
+          else
+            raise TypeError, "Unknown section: #{started}: #{section_type}"
+          end
+        end
+        contents
+      end
     end
   end
 end

test/models/fluentd/agent_common_test.rb

@@ -0,0 +1,170 @@
+require "test_helper"
+
+class Fluentd
+  class TestAgentCommon < ActiveSupport::TestCase
+    class DummyAgent
+      include ::Fluentd::Agent::Common
+    end
+
+    setup do
+      @agent = DummyAgent.new
+    end
+
+    sub_test_case "#parse_config" do
+      test "empty" do
+        actual = @agent.__send__(:parse_config, "")
+        assert_equal({}, actual)
+      end
+
+      test "simple" do
+        actual = @agent.__send__(:parse_config, fixture_content("config/simple.conf"))
+        source_section_content = <<-CONFIG.strip_heredoc.chomp
+        <source>
+          @type dummy
+          tag dummy
+        </source>
+        CONFIG
+        filter_section_content = <<-CONFIG.strip_heredoc.chomp
+        <filter dummy>
+          @type stdout
+        </filter>
+        CONFIG
+        match_section_content = <<-CONFIG.strip_heredoc.chomp
+        <match dummy>
+          @type stdout
+        </match>
+        CONFIG
+        expected = {
+          "source" => [
+            { pos: 0, content: source_section_content }
+          ],
+          "filter" => [
+            { pos: 44, content: filter_section_content }
+          ],
+          "match" => [
+            { pos: 84, content: match_section_content }
+          ]
+        }
+        assert_equal(expected, actual)
+      end
+
+      test "simple label" do
+        actual = @agent.__send__(:parse_config, fixture_content("config/label.conf"))
+        source_section_content = <<-CONFIG.strip_heredoc.chomp
+        <source>
+          @type dummy
+          tag dummy
+          @label @INPUT
+        </source>
+        CONFIG
+        filter_section_content = <<-CONFIG.chomp
+  <filter dummy>
+    @type stdout
+  </filter>
+        CONFIG
+        match_section_content = <<-CONFIG.chomp
+  <match dummy>
+    @type stdout
+  </match>
+        CONFIG
+        sections = {
+          "filter" => [
+            { pos: 75, content: filter_section_content}
+          ],
+          "match" => [
+            { pos: 121, content: match_section_content}
+          ]
+        }
+        expected = {
+          "source" => [
+            { pos: 0, content: source_section_content }
+          ],
+          "label:@INPUT" => [
+            { pos: 60, sections: sections }
+          ]
+        }
+        assert_equal(expected, actual)
+      end
+
+      test "multiple labels" do
+        actual = @agent.__send__(:parse_config, fixture_content("config/multi-label.conf"))
+        source_section_content1 = <<-CONFIG.strip_heredoc.chomp
+        <source>
+          @type dummy
+          tag dummy1
+          @label @INPUT
+        </source>
+        CONFIG
+        source_section_content2 = <<-CONFIG.strip_heredoc.chomp
+        <source>
+          @type dummy
+          tag dummy2
+          @label @INPUT
+        </source>
+        CONFIG
+        filter_section_content = <<-CONFIG.chomp
+  <filter dummy1>
+    @type stdout
+  </filter>
+        CONFIG
+        match_section_content = <<-CONFIG.chomp
+  <match dummy1>
+    @type relabel
+    @label @MAIN
+  </match>
+        CONFIG
+        input_sections = {
+          "filter" => [
+            { pos: 140, content: filter_section_content }
+          ],
+          "match" => [
+            { pos: 187, content: match_section_content }
+          ]
+        }
+        filter_secion_content1 = <<-CONFIG.chomp
+  <filter dummy1>
+    @type stdout
+  </filter>
+        CONFIG
+        filter_secion_content2 = <<-CONFIG.chomp
+  <filter dummy2>
+    @type stdout
+  </filter>
+        CONFIG
+        match_secion_content1 = <<-CONFIG.chomp
+  <match dummy1>
+    @type stdout
+  </match>
+        CONFIG
+        match_secion_content2 = <<-CONFIG.chomp
+  <match dummy2>
+    @type stdout
+  </match>
+        CONFIG
+        main_sections = {
+          "filter" => [
+            { pos: 274, content: filter_secion_content1 },
+            { pos: 321, content: filter_secion_content2 }
+          ],
+          "match" => [
+            { pos: 368, content: match_secion_content1 },
+            { pos: 413, content: match_secion_content2 }
+          ]
+        }
+        expected = {
+          "source" => [
+            { pos: 0, content: source_section_content1 },
+            { pos: 61, content: source_section_content2 },
+          ],
+          "label:@INPUT" => [
+            { pos: 124, sections: input_sections }
+          ],
+          "label:@MAIN" => [
+            { pos: 259, sections: main_sections }
+          ]
+        }
+        assert_equal(expected, actual)
+      end
+    end
+  end
+end

test/test_helper.rb

@@ -18,6 +18,10 @@ module FixturePath
   def fixture_path(fixture_name)
     Rails.root.join("test/fixtures", fixture_name).to_s
   end
+
+  def fixture_content(fixture_name)
+    Rails.root.join("test/fixtures", fixture_name).read
+  end
 end
 
 class ActiveSupport::TestCase