Fluentd::Agent::Log is now dependent class. Use composite

app/controllers/concerns/setting_concern.rb

@@ -22,7 +22,7 @@ module SettingConcern
     @fluentd.agent.config_append @setting.to_config
     if @fluentd.agent.running?
       unless @fluentd.agent.restart
-        @setting.errors.add(:base, @fluentd.agent.log_tail(1).first)
+        @setting.errors.add(:base, @fluentd.agent.log.tail(1).first)
         return render "shared/settings/show"
       end
     end

app/controllers/concerns/setting_history_concern.rb

@@ -26,7 +26,7 @@ module SettingHistoryConcern
     if @fluentd.agent.dryrun
       flash = { success: t('messages.dryrun_is_passed') }
     else
-      flash = { danger: @fluentd.agent.log_tail(1).first }
+      flash = { danger: @fluentd.agent.log.tail(1).first }
     end
     redirect_to :back, flash: flash
   end

app/controllers/fluentd/agents_controller.rb

@@ -2,7 +2,7 @@ class Fluentd::AgentsController < ApplicationController
   before_action :find_fluentd
 
   def start
-    run_action(__method__) { @fluentd.agent.log_tail(1).first }
+    run_action(__method__) { @fluentd.agent.log.tail(1).first }
     redirect_to daemon_path(@fluentd), status: 303 # 303 is change HTTP Verb GET
   end
 
@@ -12,12 +12,12 @@ class Fluentd::AgentsController < ApplicationController
   end
 
   def restart
-    run_action(__method__) { @fluentd.agent.log_tail(1).first }
+    run_action(__method__) { @fluentd.agent.log.tail(1).first }
     redirect_to daemon_path(@fluentd), status: 303 # 303 is change HTTP Verb GET
   end
 
   def log_tail
-    @logs = @fluentd.agent.log_tail(params[:limit]).reverse if @fluentd
+    @logs = @fluentd.agent.log.tail(params[:limit]).reverse if @fluentd
     render json: @logs
   end
 

app/controllers/fluentd/settings_controller.rb

@@ -39,7 +39,7 @@ class Fluentd::SettingsController < ApplicationController
     if dryrun(params[:config])
       flash.now[:success] = I18n.t('messages.dryrun_is_passed')
     else
-      flash.now[:danger] = @fluentd.agent.last_error_message
+      flash.now[:danger] = @fluentd.agent.log.last_error_message
     end
     @config = params[:config]
     render "edit"

app/controllers/fluentd_controller.rb

@@ -41,11 +41,11 @@ class FluentdController < ApplicationController
 
   def errors
     @error_duration_days = 5
-    @errors = @fluentd.agent.errors_since(@error_duration_days.days.ago)
+    @errors = @fluentd.agent.log.errors_since(@error_duration_days.days.ago)
   end
 
   def raw_log
-    send_data @fluentd.agent.log, type: "application/octet-stream", filename: File.basename(@fluentd.log_file)
+    send_data @fluentd.agent.log.to_s, type: "application/octet-stream", filename: File.basename(@fluentd.log_file)
   end
 
   private

app/controllers/misc_controller.rb

@@ -38,7 +38,7 @@ class MiscController < ApplicationController
     File.unlink(path) if File.exists?(path)
 
     Zip::File.open(path, Zip::File::CREATE) do |zip|
-      zip.get_output_stream('fluentd.log') {|f| f.puts fluentd.agent.log }
+      zip.get_output_stream('fluentd.log') {|f| f.puts fluentd.agent.log.to_s }
       zip.add("fluentd-ui.log", log_path)
 
       add_env_file_to(zip)

app/controllers/tutorials_controller.rb

@@ -5,7 +5,7 @@ class TutorialsController < ApplicationController
   helper_method :tutorial_ready?
 
   def index
-    @log = @fluentd.agent.log_tail.reverse if @fluentd
+    @log = @fluentd.agent.log.tail.reverse if @fluentd
   end
 
   def chapter1

app/models/fluentd/agent/common.rb

@@ -21,7 +21,6 @@ class Fluentd
 
       def self.included(base)
         base.include Fluentd::Agent::ProcessOperation
-        base.include Fluentd::Agent::Log
       end
 
       # define these methods on each Agent class
@@ -43,6 +42,10 @@ class Fluentd
         extra_options[:log_file] || self.class.default_options[:log_file]
       end
 
+      def log
+        @log ||= Fluentd::Agent::Log.new(log_file)
+      end
+
       def config_file
         extra_options[:config_file] || self.class.default_options[:config_file]
       end

app/models/fluentd/agent/log.rb

@@ -1,7 +1,13 @@
 class Fluentd
   class Agent
-    module Log
-      def log
+    class Log
+      attr_reader :log_file
+
+      def initialize(path)
+        @log_file = path
+      end
+
+      def to_s
         return "" unless File.exists?(log_file)
         File.read(log_file) # TODO: large log file
       end
@@ -28,7 +34,7 @@ class Fluentd
         recent_errors(1).first.try(:[], :subject) || ""
       end
 
-      def log_tail(limit = nil)
+      def tail(limit = nil)
         return [] unless File.exists?(log_file)
 
         limit = limit.to_i rescue 0

app/models/fluentd/agent/process_operation.rb

@@ -34,7 +34,7 @@ class Fluentd
       def exec_dryrun(command, file_path = nil)
         Bundler.with_clean_env do
           unless system("#{command} -q --dry-run #{options_to_argv(config_file: file_path)}", out: File::NULL, err: File::NULL)
-            raise ::Fluentd::Agent::ConfigError, last_error_message
+            raise ::Fluentd::Agent::ConfigError, "TODO"
           end
         end
       end

spec/controllers/fluentd/agents_controller_spec.rb

@@ -1,6 +1,8 @@
 require 'spec_helper'
 
 describe Fluentd::AgentsController do
+  let(:log) { double('log').as_null_object }
+
   before do
     allow(controller).to receive(:current_user).and_return true
     allow(controller).to receive(:find_fluentd).and_return(nil)
@@ -32,13 +34,15 @@ describe Fluentd::AgentsController do
 
     it "starts" do
       expect(@agent).to receive(:start).and_return false
-      expect(@agent).to receive(:log_tail).with(1).and_return ["some message"]
+      expect(@agent).to receive(:log).and_return(log)
+      expect(log).to receive(:tail).with(1)
       put :start
     end
 
     it "restarts" do
       expect(@agent).to receive(:restart).and_return false
-      expect(@agent).to receive(:log_tail).with(1).and_return ["some message"]
+      expect(@agent).to receive(:log).and_return(log)
+      expect(log).to receive(:tail).with(1)
       put :restart
     end
   end

spec/support/fluentd_agent_common_behavior.rb

@@ -35,7 +35,7 @@ shared_examples_for "Fluentd::Agent has common behavior" do |klass|
       before { Timecop.freeze(now) }
       after { Timecop.return }
 
-      subject { instance.errors_since(days.days.ago) }
+      subject { instance.log.errors_since(days.days.ago) }
 
       context "has no errors" do
         let(:logfile) { File.expand_path("./spec/support/fixtures/error0.log", Rails.root) }
@@ -73,7 +73,7 @@ shared_examples_for "Fluentd::Agent has common behavior" do |klass|
     describe "#recent_errors" do
       context "have 0 error log" do
         let(:logfile) { File.expand_path("./spec/support/fixtures/error0.log", Rails.root) }
-        subject { instance.recent_errors(2) }
+        subject { instance.log.recent_errors(2) }
 
         it "empty array" do
           should be_empty
@@ -82,10 +82,10 @@ shared_examples_for "Fluentd::Agent has common behavior" do |klass|
 
       context "have 2 error log" do
         let(:logfile) { File.expand_path("./spec/support/fixtures/error2.log", Rails.root) }
-        subject { instance.recent_errors(2) }
+        subject { instance.log.recent_errors(2) }
 
         describe "limit" do
-          subject { instance.recent_errors(limit).length }
+          subject { instance.log.recent_errors(limit).length }
 
           context "=1" do
             let(:limit) { 1 }
@@ -111,7 +111,7 @@ shared_examples_for "Fluentd::Agent has common behavior" do |klass|
 
       context "have 3 errors log includeing sequential 2 error log" do
         let(:logfile) { File.expand_path("./spec/support/fixtures/error3.log", Rails.root) }
-        subject { instance.recent_errors(3) }
+        subject { instance.log.recent_errors(3) }
 
         it "count 3 errors" do
           subject[0][:subject].should include("3 Address already in use - bind(2)")