diff --git a/test/plugin/test_in_tail.rb b/test/plugin/test_in_tail.rb
index 32b2b0b509..f88ecbefbd 100644
--- a/test/plugin/test_in_tail.rb
+++ b/test/plugin/test_in_tail.rb
@@ -13,13 +13,14 @@ class TailInputTest < Test::Unit::TestCase
   include FlexMock::TestCase
 
   def setup
+    @tmp_dir = File.join(File.dirname(__FILE__), "..", "tmp", "tail#{ENV['TEST_ENV_NUMBER']}", SecureRandom.hex(10))
     Fluent::Test.setup
-    cleanup_directory(TMP_DIR)
+    cleanup_directory(@tmp_dir)
   end
 
   def teardown
     super
-    cleanup_directory(TMP_DIR)
+    cleanup_directory(@tmp_dir)
     Fluent::Engine.stop
     Timecop.return
   end
@@ -97,23 +98,33 @@ def create_target_info(path)
                             "tag" => "t1",
                             "rotate_wait" => "2s",
                             "refresh_interval" => "1s"
-                          })
-  CONFIG = ROOT_CONFIG + config_element("", "", { "path" => "#{TMP_DIR}/tail.txt" })
-  COMMON_CONFIG = CONFIG + config_element("", "", { "pos_file" => "#{TMP_DIR}/tail.pos" })
+                               })
+
+  def base_config
+    ROOT_CONFIG + config_element("", "", { "path" => "#{@tmp_dir}/tail.txt" })
+  end
+
+  def common_config
+    base_config + config_element("", "", { "pos_file" => "#{@tmp_dir}/tail.pos" })
+  end
+
+  def common_follow_inode_config
+    config_element("ROOT", "", {
+                     "path" => "#{@tmp_dir}/tail.txt*",
+                     "pos_file" => "#{@tmp_dir}/tail.pos",
+                     "tag" => "t1",
+                     "refresh_interval" => "1s",
+                     "read_from_head" => "true",
+                     "format" => "none",
+                     "rotate_wait" => "1s",
+                     "follow_inodes" => "true"
+                   })
+  end
+
   CONFIG_READ_FROM_HEAD = config_element("", "", { "read_from_head" => true })
   CONFIG_DISABLE_WATCH_TIMER = config_element("", "", { "enable_watch_timer" => false })
   CONFIG_DISABLE_STAT_WATCHER = config_element("", "", { "enable_stat_watcher" => false })
   CONFIG_OPEN_ON_EVERY_UPDATE = config_element("", "", { "open_on_every_update" => true })
-  COMMON_FOLLOW_INODE_CONFIG = config_element("ROOT", "", {
-                                                "path" => "#{TMP_DIR}/tail.txt*",
-                                                "pos_file" => "#{TMP_DIR}/tail.pos",
-                                                "tag" => "t1",
-                                                "refresh_interval" => "1s",
-                                                "read_from_head" => "true",
-                                                "format" => "none",
-                                                "rotate_wait" => "1s",
-                                                "follow_inodes" => "true"
-                                              })
   SINGLE_LINE_CONFIG = config_element("", "", { "format" => "/(?<message>.*)/" })
   PARSE_SINGLE_LINE_CONFIG = config_element("", "", {}, [config_element("parse", "", { "@type" => "/(?<message>.*)/" })])
   MULTILINE_CONFIG = config_element(
@@ -146,7 +157,10 @@ def create_target_info(path)
                     })
     ])
 
-  TAILING_GROUP_PATTERN = "/#{TMP_DIR}\/(?<podname>[a-z0-9]([-a-z0-9]*[a-z0-9])?(\/[a-z0-9]([-a-z0-9]*[a-z0-9])?)*)_(?<namespace>[^_]+)_(?<container>.+)-(?<docker_id>[a-z0-9]{6})\.log$/"
+  def tailing_group_pattern
+    "/#{@tmp_dir}\/(?<podname>[a-z0-9]([-a-z0-9]*[a-z0-9])?(\/[a-z0-9]([-a-z0-9]*[a-z0-9])?)*)_(?<namespace>[^_]+)_(?<container>.+)-(?<docker_id>[a-z0-9]{6})\.log$/"
+  end
+
   DEBUG_LOG_LEVEL = config_element("", "", {
     "@log_level" => "debug"
   })
@@ -170,21 +184,21 @@ def create_rule_directive(match_named_captures, limit)
   end
 
   def create_path_element(path)
-    config_element("source", "", { "path" => "#{TMP_DIR}/#{path}" })
+    config_element("source", "", { "path" => "#{@tmp_dir}/#{path}" })
   end
 
   def create_driver(conf = SINGLE_LINE_CONFIG, use_common_conf = true)
-    config = use_common_conf ? COMMON_CONFIG + conf : conf
+    config = use_common_conf ? common_config + conf : conf
     Fluent::Test::Driver::Input.new(Fluent::Plugin::TailInput).configure(config)
   end
 
   sub_test_case "configure" do
     test "plain single line" do
       d = create_driver
-      assert_equal(["#{TMP_DIR}/tail.txt"], d.instance.paths)
+      assert_equal(["#{@tmp_dir}/tail.txt"], d.instance.paths)
       assert_equal("t1", d.instance.tag)
       assert_equal(2, d.instance.rotate_wait)
-      assert_equal("#{TMP_DIR}/tail.pos", d.instance.pos_file)
+      assert_equal("#{@tmp_dir}/tail.pos", d.instance.pos_file)
       assert_equal(1000, d.instance.read_lines_limit)
       assert_equal(-1, d.instance.read_bytes_limit_per_second)
       assert_equal(false, d.instance.ignore_repeated_permission_error)
@@ -222,7 +236,7 @@ def create_driver(conf = SINGLE_LINE_CONFIG, use_common_conf = true)
 
     test "follow_inodes w/o pos file" do
       assert_raise(Fluent::ConfigError) do
-        create_driver(CONFIG + config_element('', '', {'follow_inodes' => 'true'}))
+        create_driver(base_config + config_element('', '', {'follow_inodes' => 'true'}))
       end
     end
 
@@ -316,7 +330,7 @@ def create_driver(conf = SINGLE_LINE_CONFIG, use_common_conf = true)
         "namespace"=> "/namespace-h/",
       }, 0)
 
-      conf = create_group_directive(TAILING_GROUP_PATTERN, '1m', rule1, rule2, rule3, rule4) + SINGLE_LINE_CONFIG
+      conf = create_group_directive(tailing_group_pattern, '1m', rule1, rule2, rule3, rule4) + SINGLE_LINE_CONFIG
       assert_nothing_raised do
         create_driver(conf)
       end
@@ -331,7 +345,7 @@ def create_driver(conf = SINGLE_LINE_CONFIG, use_common_conf = true)
         "namespace"=> "/namespace-[d|e]/",
         "podname"=> "/podname-f/",
       }, 50)
-      conf = create_group_directive(TAILING_GROUP_PATTERN, '1m', rule1, rule2) + SINGLE_LINE_CONFIG
+      conf = create_group_directive(tailing_group_pattern, '1m', rule1, rule2) + SINGLE_LINE_CONFIG
       assert_raise(RuntimeError) do
         create_driver(conf)
       end
@@ -351,7 +365,7 @@ def create_driver(conf = SINGLE_LINE_CONFIG, use_common_conf = true)
         "namespace"=> "/namespace-a/",
       }, 100)
 
-      conf = create_group_directive(TAILING_GROUP_PATTERN, '1m', rule3, rule1, rule2) + SINGLE_LINE_CONFIG
+      conf = create_group_directive(tailing_group_pattern, '1m', rule3, rule1, rule2) + SINGLE_LINE_CONFIG
       assert_nothing_raised do
         d = create_driver(conf)
         instance = d.instance
@@ -393,12 +407,12 @@ def create_driver(conf = SINGLE_LINE_CONFIG, use_common_conf = true)
   sub_test_case "files should be placed in groups" do
     test "invalid regex pattern places files in default group" do
       rule1 = create_rule_directive({}, 100) ## limits default groups
-      conf = ROOT_CONFIG + DEBUG_LOG_LEVEL + create_group_directive(TAILING_GROUP_PATTERN, '1m', rule1) + create_path_element("test*.txt") + SINGLE_LINE_CONFIG
+      conf = ROOT_CONFIG + DEBUG_LOG_LEVEL + create_group_directive(tailing_group_pattern, '1m', rule1) + create_path_element("test*.txt") + SINGLE_LINE_CONFIG
 
       d = create_driver(conf, false)
-      File.open("#{TMP_DIR}/test1.txt", 'w')
-      File.open("#{TMP_DIR}/test2.txt", 'w')
-      File.open("#{TMP_DIR}/test3.txt", 'w')
+      File.open("#{@tmp_dir}/test1.txt", 'w')
+      File.open("#{@tmp_dir}/test2.txt", 'w')
+      File.open("#{@tmp_dir}/test3.txt", 'w')
 
       d.run do
         ## checking default group_watcher's paths
@@ -407,9 +421,9 @@ def create_driver(conf = SINGLE_LINE_CONFIG, use_common_conf = true)
 
         assert_equal(3, instance.log.logs.count{|a| a.match?("Cannot find group from metadata, Adding file in the default group\n")})
         assert_equal(3, instance.group_watchers[key].size)
-        assert_true(instance.group_watchers[key].include? File.join(TMP_DIR, 'test1.txt'))
-        assert_true(instance.group_watchers[key].include? File.join(TMP_DIR, 'test2.txt'))
-        assert_true(instance.group_watchers[key].include? File.join(TMP_DIR, 'test3.txt'))
+        assert_true(instance.group_watchers[key].include? File.join(@tmp_dir, 'test1.txt'))
+        assert_true(instance.group_watchers[key].include? File.join(@tmp_dir, 'test2.txt'))
+        assert_true(instance.group_watchers[key].include? File.join(@tmp_dir, 'test3.txt'))
       end
     end
 
@@ -428,13 +442,13 @@ def create_driver(conf = SINGLE_LINE_CONFIG, use_common_conf = true)
 
       path_element = create_path_element("test-podname*.log")
 
-      conf = ROOT_CONFIG + create_group_directive(TAILING_GROUP_PATTERN, '1m', rule4, rule3, rule2, rule1) + path_element + SINGLE_LINE_CONFIG
+      conf = ROOT_CONFIG + create_group_directive(tailing_group_pattern, '1m', rule4, rule3, rule2, rule1) + path_element + SINGLE_LINE_CONFIG
       d = create_driver(conf, false)
 
-      file1 = File.join(TMP_DIR, "test-podname1_test-namespace1_test-container-15fabq.log")
-      file2 = File.join(TMP_DIR, "test-podname3_test-namespace1_test-container-15fabq.log")
-      file3 = File.join(TMP_DIR, "test-podname2_test-namespace2_test-container-15fabq.log")
-      file4 = File.join(TMP_DIR, "test-podname4_test-namespace3_test-container-15fabq.log")
+      file1 = File.join(@tmp_dir, "test-podname1_test-namespace1_test-container-15fabq.log")
+      file2 = File.join(@tmp_dir, "test-podname3_test-namespace1_test-container-15fabq.log")
+      file3 = File.join(@tmp_dir, "test-podname2_test-namespace2_test-container-15fabq.log")
+      file4 = File.join(@tmp_dir, "test-podname4_test-namespace3_test-container-15fabq.log")
 
       d.run do
         File.open(file1, 'w')
@@ -456,7 +470,7 @@ def create_driver(conf = SINGLE_LINE_CONFIG, use_common_conf = true)
          parse: PARSE_SINGLE_LINE_CONFIG)
     def test_emit(data)
       config = data
-      File.open("#{TMP_DIR}/tail.txt", "wb") {|f|
+      File.open("#{@tmp_dir}/tail.txt", "wb") {|f|
         f.puts "test1"
         f.puts "test2"
       }
@@ -464,7 +478,7 @@ def test_emit(data)
       d = create_driver(config)
 
       d.run(expect_emits: 1) do
-        File.open("#{TMP_DIR}/tail.txt", "ab") {|f|
+        File.open("#{@tmp_dir}/tail.txt", "ab") {|f|
           f.puts "test3\ntest4"
         }
       end
@@ -480,11 +494,11 @@ def test_emit(data)
 
     def test_emit_with_emit_unmatched_lines_true
       config = config_element("", "", { "format" => "/^(?<message>test.*)/", "emit_unmatched_lines" => true })
-      File.open("#{TMP_DIR}/tail.txt", "wb") { |f| }
+      File.open("#{@tmp_dir}/tail.txt", "wb") { |f| }
 
       d = create_driver(config)
       d.run(expect_emits: 1) do
-        File.open("#{TMP_DIR}/tail.txt", "ab") {|f|
+        File.open("#{@tmp_dir}/tail.txt", "ab") {|f|
           f.puts "test line 1"
           f.puts "test line 2"
           f.puts "bad line 1"
@@ -516,7 +530,7 @@ def test_emit_with_read_lines_limit(data)
       msg = 'test' * 2000 # in_tail reads 8192 bytes at once.
 
       d.run(expect_emits: num_events, timeout: 2) do
-        File.open("#{TMP_DIR}/tail.txt", "ab") {|f|
+        File.open("#{@tmp_dir}/tail.txt", "ab") {|f|
           f.puts msg
           f.puts msg
         }
@@ -531,7 +545,7 @@ def test_emit_with_read_lines_limit(data)
 
     sub_test_case "log throttling per file" do
       teardown do
-        cleanup_file("#{TMP_DIR}/tail.txt")
+        cleanup_file("#{@tmp_dir}/tail.txt")
       end
 
       sub_test_case "reads_bytes_per_second w/o throttled" do
@@ -562,7 +576,7 @@ def test_emit_with_read_bytes_limit_per_second(data)
 
           d = create_driver(config)
           d.run(expect_emits: 2) do
-            File.open("#{TMP_DIR}/tail.txt", "ab") {|f|
+            File.open("#{@tmp_dir}/tail.txt", "ab") {|f|
               100.times do
                 f.puts msg
               end
@@ -585,7 +599,7 @@ def test_read_bytes_limit_precede_read_lines_limit
           start_time = Fluent::Clock.now
           d = create_driver(config)
           d.run(expect_emits: 2) do
-            File.open("#{TMP_DIR}/tail.txt", "ab") {|f|
+            File.open("#{@tmp_dir}/tail.txt", "ab") {|f|
               8000.times do
                 f.puts msg
               end
@@ -624,7 +638,7 @@ def test_emit_with_read_bytes_limit_per_second(data)
             io_handler
           end
 
-          File.open("#{TMP_DIR}/tail.txt", "ab") do |f|
+          File.open("#{@tmp_dir}/tail.txt", "ab") do |f|
             100.times do
               f.puts msg
             end
@@ -634,7 +648,7 @@ def test_emit_with_read_bytes_limit_per_second(data)
           d.run do
             start_time = Fluent::Clock.now
             while Fluent::Clock.now - start_time < 0.8 do
-              File.open("#{TMP_DIR}/tail.txt", "ab") do |f|
+              File.open("#{@tmp_dir}/tail.txt", "ab") do |f|
                 f.puts msg
                 f.flush
               end
@@ -652,7 +666,7 @@ def test_longer_than_rotate_wait
           num_lines = 1024 * 3
           msg = "08bytes"
 
-          File.open("#{TMP_DIR}/tail.txt", "wb") do |f|
+          File.open("#{@tmp_dir}/tail.txt", "wb") do |f|
             f.write("#{msg}\n" * num_lines)
           end
 
@@ -669,8 +683,8 @@ def test_longer_than_rotate_wait
           d.run(timeout: 10) do
             while d.events.size < num_lines do
               if d.events.size > 0 && !rotated
-                cleanup_file("#{TMP_DIR}/tail.txt")
-                FileUtils.touch("#{TMP_DIR}/tail.txt")
+                cleanup_file("#{@tmp_dir}/tail.txt")
+                FileUtils.touch("#{@tmp_dir}/tail.txt")
                 rotated = true
               end
               sleep 0.3
@@ -688,7 +702,7 @@ def test_shorter_than_rotate_wait
           num_lines = 1024 * 2
           msg = "08bytes"
 
-          File.open("#{TMP_DIR}/tail.txt", "wb") do |f|
+          File.open("#{@tmp_dir}/tail.txt", "wb") do |f|
             f.write("#{msg}\n" * num_lines)
           end
 
@@ -715,8 +729,8 @@ def test_shorter_than_rotate_wait
           d.run(timeout: 10) do
             until detached do
               if d.events.size > 0 && !rotated
-                cleanup_file("#{TMP_DIR}/tail.txt")
-                FileUtils.touch("#{TMP_DIR}/tail.txt")
+                cleanup_file("#{@tmp_dir}/tail.txt")
+                FileUtils.touch("#{@tmp_dir}/tail.txt")
                 rotated = true
               end
               sleep 0.3
@@ -736,7 +750,7 @@ def test_shorter_than_rotate_wait
          parse: CONFIG_READ_FROM_HEAD + PARSE_SINGLE_LINE_CONFIG)
     def test_emit_with_read_from_head(data)
       config = data
-      File.open("#{TMP_DIR}/tail.txt", "wb") {|f|
+      File.open("#{@tmp_dir}/tail.txt", "wb") {|f|
         f.puts "test1"
         f.puts "test2"
       }
@@ -744,7 +758,7 @@ def test_emit_with_read_from_head(data)
       d = create_driver(config)
 
       d.run(expect_emits: 2) do
-        File.open("#{TMP_DIR}/tail.txt", "ab") {|f|
+        File.open("#{@tmp_dir}/tail.txt", "ab") {|f|
           f.puts "test3"
           f.puts "test4"
         }
@@ -762,7 +776,7 @@ def test_emit_with_read_from_head(data)
          parse: CONFIG_DISABLE_WATCH_TIMER + PARSE_SINGLE_LINE_CONFIG)
     def test_emit_without_watch_timer(data)
       config = data
-      File.open("#{TMP_DIR}/tail.txt", "wb") {|f|
+      File.open("#{@tmp_dir}/tail.txt", "wb") {|f|
         f.puts "test1"
         f.puts "test2"
       }
@@ -770,7 +784,7 @@ def test_emit_without_watch_timer(data)
       d = create_driver(config)
 
       d.run(expect_emits: 1) do
-        File.open("#{TMP_DIR}/tail.txt", "ab") {|f|
+        File.open("#{@tmp_dir}/tail.txt", "ab") {|f|
           f.puts "test3"
           f.puts "test4"
         }
@@ -789,12 +803,12 @@ def test_watch_wildcard_path_without_watch_timer
       omit "need inotify" unless Fluent.linux?
 
       config = config_element("ROOT", "", {
-                                "path" => "#{TMP_DIR}/tail*.txt",
+                                "path" => "#{@tmp_dir}/tail*.txt",
                                 "tag" => "t1",
                               })
       config = config + CONFIG_DISABLE_WATCH_TIMER + SINGLE_LINE_CONFIG
 
-      File.open("#{TMP_DIR}/tail.txt", "wb") {|f|
+      File.open("#{@tmp_dir}/tail.txt", "wb") {|f|
         f.puts "test1"
         f.puts "test2"
       }
@@ -802,7 +816,7 @@ def test_watch_wildcard_path_without_watch_timer
       d = create_driver(config, false)
 
       d.run(expect_emits: 1, timeout: 1) do
-        File.open("#{TMP_DIR}/tail.txt", "ab") {|f|
+        File.open("#{@tmp_dir}/tail.txt", "ab") {|f|
           f.puts "test3"
           f.puts "test4"
         }
@@ -820,7 +834,7 @@ def test_watch_wildcard_path_without_watch_timer
          parse: CONFIG_DISABLE_STAT_WATCHER + PARSE_SINGLE_LINE_CONFIG)
     def test_emit_with_disable_stat_watcher(data)
       config = data
-      File.open("#{TMP_DIR}/tail.txt", "wb") {|f|
+      File.open("#{@tmp_dir}/tail.txt", "wb") {|f|
         f.puts "test1"
         f.puts "test2"
       }
@@ -828,7 +842,7 @@ def test_emit_with_disable_stat_watcher(data)
       d = create_driver(config)
 
       d.run(expect_emits: 1) do
-        File.open("#{TMP_DIR}/tail.txt", "ab") {|f|
+        File.open("#{@tmp_dir}/tail.txt", "ab") {|f|
           f.puts "test3"
           f.puts "test4"
         }
@@ -844,7 +858,7 @@ def test_always_read_from_head_on_detecting_a_new_file
       d = create_driver(SINGLE_LINE_CONFIG)
 
       d.run(expect_emits: 1, timeout: 3) do
-        File.open("#{TMP_DIR}/tail.txt", "wb") {|f|
+        File.open("#{@tmp_dir}/tail.txt", "wb") {|f|
           f.puts "test1\ntest2\n"
         }
       end
@@ -888,7 +902,7 @@ def test_emit_with_system
       system_conf = parse_system(CONFIG_SYSTEM)
       sc = Fluent::SystemConfig.new(system_conf)
       Fluent::Engine.init(sc)
-      File.open("#{TMP_DIR}/tail.txt", "wb") {|f|
+      File.open("#{@tmp_dir}/tail.txt", "wb") {|f|
         f.puts "test1"
         f.puts "test2"
       }
@@ -896,7 +910,7 @@ def test_emit_with_system
       d = create_driver
 
       d.run(expect_emits: 1) do
-        File.open("#{TMP_DIR}/tail.txt", "ab") {|f|
+        File.open("#{@tmp_dir}/tail.txt", "ab") {|f|
           f.puts "test3"
           f.puts "test4"
         }
@@ -916,6 +930,11 @@ def test_emit_with_system
   end
 
   sub_test_case "rotate file" do
+    def create_driver(conf = SINGLE_LINE_CONFIG)
+      config = common_config + conf
+      Fluent::Test::Driver::Input.new(Fluent::Plugin::TailInput).configure(config)
+    end
+
     data(flat: SINGLE_LINE_CONFIG,
          parse: PARSE_SINGLE_LINE_CONFIG)
     def test_rotate_file(data)
@@ -948,13 +967,13 @@ def test_rotate_file_with_open_on_every_update(data)
     def test_rotate_file_with_write_old(data)
       config = data
       events = sub_test_rotate_file(config, expect_emits: 3) { |rotated_file|
-        File.open("#{TMP_DIR}/tail.txt", "wb") { |f| }
+        File.open("#{@tmp_dir}/tail.txt", "wb") { |f| }
         rotated_file.puts "test7"
         rotated_file.puts "test8"
         rotated_file.flush
 
         sleep 1
-        File.open("#{TMP_DIR}/tail.txt", "ab") { |f|
+        File.open("#{@tmp_dir}/tail.txt", "ab") { |f|
           f.puts "test5"
           f.puts "test6"
         }
@@ -979,7 +998,7 @@ def test_rotate_file_with_write_old_and_no_new_file(data)
     end
 
     def sub_test_rotate_file(config = nil, expect_emits: nil, expect_records: nil, timeout: 5)
-      file = Fluent::FileWrapper.open("#{TMP_DIR}/tail.txt", "wb")
+      file = Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb")
       file.puts "test1"
       file.puts "test2"
       file.flush
@@ -996,18 +1015,18 @@ def sub_test_rotate_file(config = nil, expect_emits: nil, expect_records: nil, t
 
         if Fluent.windows?
           file.close
-          FileUtils.mv("#{TMP_DIR}/tail.txt", "#{TMP_DIR}/tail2.txt", force: true)
-          file = Fluent::FileWrapper.open("#{TMP_DIR}/tail2.txt", "ab")
+          FileUtils.mv("#{@tmp_dir}/tail.txt", "#{@tmp_dir}/tail2.txt", force: true)
+          file = Fluent::FileWrapper.open("#{@tmp_dir}/tail2.txt", "ab")
         else
-          FileUtils.mv("#{TMP_DIR}/tail.txt", "#{TMP_DIR}/tail2.txt")
+          FileUtils.mv("#{@tmp_dir}/tail.txt", "#{@tmp_dir}/tail2.txt")
         end
         if block_given?
           yield file
         else
-          File.open("#{TMP_DIR}/tail.txt", "wb") { |f| }
+          File.open("#{@tmp_dir}/tail.txt", "wb") { |f| }
           sleep 1
 
-          File.open("#{TMP_DIR}/tail.txt", "ab") { |f|
+          File.open("#{@tmp_dir}/tail.txt", "ab") { |f|
             f.puts "test5"
             f.puts "test6"
           }
@@ -1024,7 +1043,7 @@ def test_truncate_file
     omit "Permission denied error happen on Windows. Need fix" if Fluent.windows?
 
     config = SINGLE_LINE_CONFIG
-    File.open("#{TMP_DIR}/tail.txt", "wb") {|f|
+    File.open("#{@tmp_dir}/tail.txt", "wb") {|f|
       f.puts "test1"
       f.puts "test2"
       f.flush
@@ -1033,12 +1052,12 @@ def test_truncate_file
     d = create_driver(config)
 
     d.run(expect_emits: 2) do
-      File.open("#{TMP_DIR}/tail.txt", "ab") {|f|
+      File.open("#{@tmp_dir}/tail.txt", "ab") {|f|
         f.puts "test3\ntest4"
         f.flush
       }
       waiting(2) { sleep 0.1 until d.events.length == 2 }
-      File.truncate("#{TMP_DIR}/tail.txt", 6)
+      File.truncate("#{@tmp_dir}/tail.txt", 6)
     end
 
     expected = {
@@ -1060,7 +1079,7 @@ def test_move_truncate_move_back
     omit "Permission denied error happen on Windows. Need fix" if Fluent.windows?
 
     config = SINGLE_LINE_CONFIG
-    File.open("#{TMP_DIR}/tail.txt", "wb") {|f|
+    File.open("#{@tmp_dir}/tail.txt", "wb") {|f|
       f.puts "test1"
       f.puts "test2"
     }
@@ -1069,17 +1088,17 @@ def test_move_truncate_move_back
 
     d.run(expect_emits: 1) do
       if Fluent.windows?
-        FileUtils.mv("#{TMP_DIR}/tail.txt", "#{TMP_DIR}/tail2.txt", force: true)
+        FileUtils.mv("#{@tmp_dir}/tail.txt", "#{@tmp_dir}/tail2.txt", force: true)
       else
-        FileUtils.mv("#{TMP_DIR}/tail.txt", "#{TMP_DIR}/tail2.txt")
+        FileUtils.mv("#{@tmp_dir}/tail.txt", "#{@tmp_dir}/tail2.txt")
       end
       sleep(1)
-      File.truncate("#{TMP_DIR}/tail2.txt", 6)
+      File.truncate("#{@tmp_dir}/tail2.txt", 6)
       sleep(1)
       if Fluent.windows?
-        FileUtils.mv("#{TMP_DIR}/tail2.txt", "#{TMP_DIR}/tail.txt", force: true)
+        FileUtils.mv("#{@tmp_dir}/tail2.txt", "#{@tmp_dir}/tail.txt", force: true)
       else
-        FileUtils.mv("#{TMP_DIR}/tail2.txt", "#{TMP_DIR}/tail.txt")
+        FileUtils.mv("#{@tmp_dir}/tail2.txt", "#{@tmp_dir}/tail.txt")
       end
     end
 
@@ -1091,17 +1110,17 @@ def test_move_truncate_move_back
   end
 
   def test_lf
-    File.open("#{TMP_DIR}/tail.txt", "wb") {|f| }
+    File.open("#{@tmp_dir}/tail.txt", "wb") {|f| }
 
     d = create_driver
 
     d.run(expect_emits: 1) do
-      File.open("#{TMP_DIR}/tail.txt", "ab") {|f|
+      File.open("#{@tmp_dir}/tail.txt", "ab") {|f|
         f.print "test3"
       }
       sleep 1
 
-      File.open("#{TMP_DIR}/tail.txt", "ab") {|f|
+      File.open("#{@tmp_dir}/tail.txt", "ab") {|f|
         f.puts "test4"
       }
     end
@@ -1112,12 +1131,12 @@ def test_lf
   end
 
   def test_whitespace
-    File.open("#{TMP_DIR}/tail.txt", "wb") {|f| }
+    File.open("#{@tmp_dir}/tail.txt", "wb") {|f| }
 
     d = create_driver
 
     d.run(expect_emits: 1) do
-      File.open("#{TMP_DIR}/tail.txt", "ab") {|f|
+      File.open("#{@tmp_dir}/tail.txt", "ab") {|f|
         f.puts "    "		# 4 spaces
         f.puts "    4 spaces"
         f.puts "4 spaces    "
@@ -1148,7 +1167,7 @@ def test_encoding(data)
     d = create_driver(CONFIG_READ_FROM_HEAD + encoding_config)
 
     d.run(expect_emits: 1) do
-      File.open("#{TMP_DIR}/tail.txt", "wb") {|f|
+      File.open("#{@tmp_dir}/tail.txt", "wb") {|f|
         f.puts "test"
       }
     end
@@ -1170,7 +1189,7 @@ def test_from_encoding
     utf8_message = cp932_message.encode(Encoding::UTF_8)
 
     d.run(expect_emits: 1) do
-      File.open("#{TMP_DIR}/tail.txt", "w:cp932") {|f|
+      File.open("#{@tmp_dir}/tail.txt", "w:cp932") {|f|
         f.puts cp932_message
       }
     end
@@ -1193,7 +1212,7 @@ def test_from_encoding_utf16
     utf8_message = utf16_message.encode(Encoding::UTF_8).strip
 
     d.run(expect_emits: 1) do
-      File.open("#{TMP_DIR}/tail.txt", "w:utf-16le") { |f|
+      File.open("#{@tmp_dir}/tail.txt", "w:utf-16le") { |f|
         f.write utf16_message
       }
     end
@@ -1214,7 +1233,7 @@ def test_encoding_with_bad_character
     d = create_driver(conf)
 
     d.run(expect_emits: 1) do
-      File.open("#{TMP_DIR}/tail.txt", "w") { |f|
+      File.open("#{@tmp_dir}/tail.txt", "w") { |f|
         f.write "te\x86st\n"
       }
     end
@@ -1229,11 +1248,11 @@ def test_encoding_with_bad_character
          parse: PARSE_MULTILINE_CONFIG)
     def test_multiline(data)
       config = data
-      File.open("#{TMP_DIR}/tail.txt", "wb") { |f| }
+      File.open("#{@tmp_dir}/tail.txt", "wb") { |f| }
 
       d = create_driver(config)
       d.run(expect_emits: 1) do
-        File.open("#{TMP_DIR}/tail.txt", "ab") { |f|
+        File.open("#{@tmp_dir}/tail.txt", "ab") { |f|
           f.puts "f test1"
           f.puts "s test2"
           f.puts "f test3"
@@ -1257,11 +1276,11 @@ def test_multiline(data)
          parse: PARSE_MULTILINE_CONFIG)
     def test_multiline_with_emit_unmatched_lines_true(data)
       config = data + config_element("", "", { "emit_unmatched_lines" => true })
-      File.open("#{TMP_DIR}/tail.txt", "wb") { |f| }
+      File.open("#{@tmp_dir}/tail.txt", "wb") { |f| }
 
       d = create_driver(config)
       d.run(expect_emits: 1) do
-        File.open("#{TMP_DIR}/tail.txt", "ab") { |f|
+        File.open("#{@tmp_dir}/tail.txt", "ab") { |f|
           f.puts "f test1"
           f.puts "s test2"
           f.puts "f test3"
@@ -1287,11 +1306,11 @@ def test_multiline_with_emit_unmatched_lines_true(data)
       parse: PARSE_MULTILINE_CONFIG_WITH_NEWLINE)
     def test_multiline_with_emit_unmatched_lines2(data)
       config = data + config_element("", "", { "emit_unmatched_lines" => true })
-      File.open("#{TMP_DIR}/tail.txt", "wb") { |f| }
+      File.open("#{@tmp_dir}/tail.txt", "wb") { |f| }
 
       d = create_driver(config)
       d.run(expect_emits: 0, timeout: 1) do
-        File.open("#{TMP_DIR}/tail.txt", "ab") { |f|
+        File.open("#{@tmp_dir}/tail.txt", "ab") { |f|
           f.puts "s test0"
           f.puts "f test1"
           f.puts "f test2"
@@ -1313,7 +1332,7 @@ def test_multiline_with_emit_unmatched_lines2(data)
     data(flat: MULTILINE_CONFIG,
          parse: PARSE_MULTILINE_CONFIG)
     def test_multiline_with_flush_interval(data)
-      File.open("#{TMP_DIR}/tail.txt", "wb") { |f| }
+      File.open("#{@tmp_dir}/tail.txt", "wb") { |f| }
 
       config = data + config_element("", "", { "multiline_flush_interval" => "2s" })
       d = create_driver(config)
@@ -1321,7 +1340,7 @@ def test_multiline_with_flush_interval(data)
       assert_equal(2, d.instance.multiline_flush_interval)
 
       d.run(expect_emits: 1) do
-        File.open("#{TMP_DIR}/tail.txt", "ab") { |f|
+        File.open("#{@tmp_dir}/tail.txt", "ab") { |f|
           f.puts "f test1"
           f.puts "s test2"
           f.puts "f test3"
@@ -1356,7 +1375,7 @@ def test_multiline_encoding_of_flushed_record(data)
       d = create_driver(config + encoding_config)
 
       d.run(expect_emits: 1) do
-        File.open("#{TMP_DIR}/tail.txt", "wb") { |f|
+        File.open("#{@tmp_dir}/tail.txt", "wb") { |f|
           f.puts "s test"
         }
       end
@@ -1379,7 +1398,7 @@ def test_multiline_from_encoding_of_flushed_record
       cp932_message = "s \x82\xCD\x82\xEB\x81\x5B\x82\xED\x81\x5B\x82\xE9\x82\xC7".force_encoding(Encoding::CP932)
       utf8_message = "\x82\xCD\x82\xEB\x81\x5B\x82\xED\x81\x5B\x82\xE9\x82\xC7".encode(Encoding::UTF_8, Encoding::CP932)
       d.run(expect_emits: 1) do
-        File.open("#{TMP_DIR}/tail.txt", "w:cp932") { |f|
+        File.open("#{@tmp_dir}/tail.txt", "w:cp932") { |f|
           f.puts cp932_message
         }
       end
@@ -1411,11 +1430,11 @@ def test_multiline_from_encoding_of_flushed_record
         )
     def test_multiline_with_multiple_formats(data)
       config = data
-      File.open("#{TMP_DIR}/tail.txt", "wb") { |f| }
+      File.open("#{@tmp_dir}/tail.txt", "wb") { |f| }
 
       d = create_driver(config)
       d.run(expect_emits: 1) do
-        File.open("#{TMP_DIR}/tail.txt", "ab") { |f|
+        File.open("#{@tmp_dir}/tail.txt", "ab") { |f|
           f.puts "f test1"
           f.puts "s test2"
           f.puts "f test3"
@@ -1451,7 +1470,7 @@ def test_multiline_with_multiple_formats(data)
            ])
         )
     def test_multilinelog_with_multiple_paths(data)
-      files = ["#{TMP_DIR}/tail1.txt", "#{TMP_DIR}/tail2.txt"]
+      files = ["#{@tmp_dir}/tail1.txt", "#{@tmp_dir}/tail2.txt"]
       files.each { |file| File.open(file, "wb") { |f| } }
 
       config = data + config_element("", "", {
@@ -1496,12 +1515,12 @@ def test_multilinelog_with_multiple_paths(data)
            ])
         )
     def test_multiline_without_firstline(data)
-      File.open("#{TMP_DIR}/tail.txt", "wb") { |f| }
+      File.open("#{@tmp_dir}/tail.txt", "wb") { |f| }
 
       config = data
       d = create_driver(config)
       d.run(expect_emits: 1) do
-        File.open("#{TMP_DIR}/tail.txt", "ab") { |f|
+        File.open("#{@tmp_dir}/tail.txt", "ab") { |f|
           f.puts "foo 1"
           f.puts "bar 1"
           f.puts "baz 1"
@@ -1528,7 +1547,7 @@ def test_multiline_without_firstline(data)
                                  "tag" => "tail",
                                  "path" => "test/plugin/*/%Y/%m/%Y%m%d-%H%M%S.log,test/plugin/data/log/**/*.log",
                                  "format" => "none",
-                                 "pos_file" => "#{TMP_DIR}/tail.pos",
+                                 "pos_file" => "#{@tmp_dir}/tail.pos",
                                  "read_from_head" => true,
                                  "refresh_interval" => 30,
                                  "rotate_wait" => "#{EX_ROTATE_WAIT}s",
@@ -1601,7 +1620,7 @@ def test_log_file_without_extension
         "tag" => "tail",
         "path" => "test/plugin/data/log/**/*",
         "format" => "none",
-        "pos_file" => "#{TMP_DIR}/tail.pos"
+        "pos_file" => "#{@tmp_dir}/tail.pos"
       })
 
       plugin = create_driver(config, false).instance
@@ -1611,20 +1630,20 @@ def test_log_file_without_extension
     def test_unwatched_files_should_be_removed
       config = config_element("", "", {
                                 "tag" => "tail",
-                                "path" => "#{TMP_DIR}/*.txt",
+                                "path" => "#{@tmp_dir}/*.txt",
                                 "format" => "none",
-                                "pos_file" => "#{TMP_DIR}/tail.pos",
+                                "pos_file" => "#{@tmp_dir}/tail.pos",
                                 "read_from_head" => true,
                                 "refresh_interval" => 1,
                               })
       d = create_driver(config, false)
       d.end_if { d.instance.instance_variable_get(:@tails).keys.size >= 1 }
       d.run(expect_emits: 1, shutdown: false) do
-        File.open("#{TMP_DIR}/tail.txt", "ab") { |f| f.puts "test3\n" }
+        File.open("#{@tmp_dir}/tail.txt", "ab") { |f| f.puts "test3\n" }
       end
 
-      cleanup_directory(TMP_DIR)
-      waiting(20) { sleep 0.1 until Dir.glob("#{TMP_DIR}/*.txt").size == 0 } # Ensure file is deleted on Windows
+      cleanup_directory(@tmp_dir)
+      waiting(20) { sleep 0.1 until Dir.glob("#{@tmp_dir}/*.txt").size == 0 } # Ensure file is deleted on Windows
       waiting(5) { sleep 0.1 until d.instance.instance_variable_get(:@tails).keys.size <= 0 }
 
       assert_equal(0, d.instance.instance_variable_get(:@tails).keys.size)
@@ -1687,47 +1706,47 @@ def capability_enabled?
   def test_pos_file_dir_creation
     config = config_element("", "", {
       "tag" => "tail",
-      "path" => "#{TMP_DIR}/*.txt",
+      "path" => "#{@tmp_dir}/*.txt",
       "format" => "none",
-      "pos_file" => "#{TMP_DIR}/pos/tail.pos",
+      "pos_file" => "#{@tmp_dir}/pos/tail.pos",
       "read_from_head" => true,
       "refresh_interval" => 1
     })
 
-    assert_path_not_exist("#{TMP_DIR}/pos")
+    assert_path_not_exist("#{@tmp_dir}/pos")
     d = create_driver(config, false)
     d.run
-    assert_path_exist("#{TMP_DIR}/pos")
-    assert_equal('755', File.stat("#{TMP_DIR}/pos").mode.to_s(8)[-3, 3])
+    assert_path_exist("#{@tmp_dir}/pos")
+    assert_equal('755', File.stat("#{@tmp_dir}/pos").mode.to_s(8)[-3, 3])
   ensure
-    cleanup_directory(TMP_DIR)
+    cleanup_directory(@tmp_dir)
   end
 
   def test_pos_file_dir_creation_with_system_dir_permission
     config = config_element("", "", {
       "tag" => "tail",
-      "path" => "#{TMP_DIR}/*.txt",
+      "path" => "#{@tmp_dir}/*.txt",
       "format" => "none",
-      "pos_file" => "#{TMP_DIR}/pos/tail.pos",
+      "pos_file" => "#{@tmp_dir}/pos/tail.pos",
       "read_from_head" => true,
       "refresh_interval" => 1
     })
 
-    assert_path_not_exist("#{TMP_DIR}/pos")
+    assert_path_not_exist("#{@tmp_dir}/pos")
 
     Fluent::SystemConfig.overwrite_system_config({ "dir_permission" => "744" }) do
       d = create_driver(config, false)
       d.run
     end
 
-    assert_path_exist("#{TMP_DIR}/pos")
+    assert_path_exist("#{@tmp_dir}/pos")
     if Fluent.windows?
-      assert_equal('755', File.stat("#{TMP_DIR}/pos").mode.to_s(8)[-3, 3])
+      assert_equal('755', File.stat("#{@tmp_dir}/pos").mode.to_s(8)[-3, 3])
     else
-      assert_equal('744', File.stat("#{TMP_DIR}/pos").mode.to_s(8)[-3, 3])
+      assert_equal('744', File.stat("#{@tmp_dir}/pos").mode.to_s(8)[-3, 3])
     end
   ensure
-    cleanup_directory(TMP_DIR)
+    cleanup_directory(@tmp_dir)
   end
 
   def test_z_refresh_watchers
@@ -1779,9 +1798,9 @@ def test_z_refresh_watchers
     test 'type of pos_file_compaction_interval is time' do
       tail = {
         "tag" => "tail",
-        "path" => "#{TMP_DIR}/*.txt",
+        "path" => "#{@tmp_dir}/*.txt",
         "format" => "none",
-        "pos_file" => "#{TMP_DIR}/pos/tail.pos",
+        "pos_file" => "#{@tmp_dir}/pos/tail.pos",
         "refresh_interval" => 1,
         "read_from_head" => true,
         'pos_file_compaction_interval' => '24h',
@@ -1882,13 +1901,13 @@ def test_tag_prefix_and_suffix_ignore
     test 'max_line_size' do |(label, size)|
       config = config_element("", "", {
                                 "tag" => "max_line_size",
-                                "path" => "#{TMP_DIR}/with_long_lines.txt",
+                                "path" => "#{@tmp_dir}/with_long_lines.txt",
                                 "format" => "none",
                                 "read_from_head" => true,
                                 "max_line_size" => label,
                                 "log_level" => "debug"
                               })
-      File.open("#{TMP_DIR}/with_long_lines.txt", "w+") do |f|
+      File.open("#{@tmp_dir}/with_long_lines.txt", "w+") do |f|
         f.puts "foo"
         f.puts "x" * size # 'x' * size + \n > @max_line_size
         f.puts "bar"
@@ -1914,7 +1933,7 @@ def test_tag_prefix_and_suffix_ignore
   # Ensure that no fatal exception is raised when a file is missing and that
   # files that do exist are still tailed as expected.
   def test_missing_file
-    File.open("#{TMP_DIR}/tail.txt", "wb") {|f|
+    File.open("#{@tmp_dir}/tail.txt", "wb") {|f|
       f.puts "test1"
       f.puts "test2"
     }
@@ -1923,16 +1942,16 @@ def test_missing_file
     # since their interactions with the filesystem differ.
     config1 = config_element("", "", {
                                "tag" => "t1",
-                               "path" => "#{TMP_DIR}/non_existent_file.txt,#{TMP_DIR}/tail.txt",
+                               "path" => "#{@tmp_dir}/non_existent_file.txt,#{@tmp_dir}/tail.txt",
                                "format" => "none",
                                "rotate_wait" => "2s",
-                               "pos_file" => "#{TMP_DIR}/tail.pos"
+                               "pos_file" => "#{@tmp_dir}/tail.pos"
                              })
     config2 = config1 + config_element("", "", { "read_from_head" => true })
     [config1, config2].each do |config|
       d = create_driver(config, false)
       d.run(expect_emits: 1) do
-        File.open("#{TMP_DIR}/tail.txt", "ab") {|f|
+        File.open("#{@tmp_dir}/tail.txt", "ab") {|f|
           f.puts "test3"
           f.puts "test4"
         }
@@ -1948,19 +1967,19 @@ def test_missing_file
 
   sub_test_case 'inode_processing' do
     def test_should_delete_file_pos_entry_for_non_existing_file_with_follow_inodes
-      config = COMMON_FOLLOW_INODE_CONFIG
+      config = common_follow_inode_config
 
-      path = "#{TMP_DIR}/tail.txt"
+      path = "#{@tmp_dir}/tail.txt"
       ino = 1
       pos = 1234
-      File.open("#{TMP_DIR}/tail.pos", "wb") {|f|
+      File.open("#{@tmp_dir}/tail.pos", "wb") {|f|
         f.puts ("%s\t%016x\t%016x\n" % [path, pos, ino])
       }
 
       d = create_driver(config, false)
       d.run
 
-      pos_file = File.open("#{TMP_DIR}/tail.pos", "r")
+      pos_file = File.open("#{@tmp_dir}/tail.pos", "r")
       pos_file.pos = 0
 
       assert_raise(EOFError) do
@@ -1969,21 +1988,21 @@ def test_should_delete_file_pos_entry_for_non_existing_file_with_follow_inodes
     end
 
     def test_should_write_latest_offset_after_rotate_wait
-      config = COMMON_FOLLOW_INODE_CONFIG
-      File.open("#{TMP_DIR}/tail.txt", "wb") {|f|
+      config = common_follow_inode_config
+      File.open("#{@tmp_dir}/tail.txt", "wb") {|f|
         f.puts "test1"
         f.puts "test2"
       }
 
       d = create_driver(config, false)
       d.run(expect_emits: 2, shutdown: false) do
-        File.open("#{TMP_DIR}/tail.txt", "ab") {|f| f.puts "test3\n"}
-        FileUtils.move("#{TMP_DIR}/tail.txt", "#{TMP_DIR}/tail.txt" + "1")
+        File.open("#{@tmp_dir}/tail.txt", "ab") {|f| f.puts "test3\n"}
+        FileUtils.move("#{@tmp_dir}/tail.txt", "#{@tmp_dir}/tail.txt" + "1")
         sleep 1
-        File.open("#{TMP_DIR}/tail.txt" + "1", "ab") {|f| f.puts "test4\n"}
+        File.open("#{@tmp_dir}/tail.txt" + "1", "ab") {|f| f.puts "test4\n"}
       end
 
-      pos_file = File.open("#{TMP_DIR}/tail.pos", "r")
+      pos_file = File.open("#{@tmp_dir}/tail.pos", "r")
       pos_file.pos = 0
       line_parts = /^([^\t]+)\t([0-9a-fA-F]+)\t([0-9a-fA-F]+)/.match(pos_file.readline)
       waiting(5) {
@@ -2000,16 +2019,16 @@ def test_should_write_latest_offset_after_rotate_wait
     def test_should_remove_deleted_file
       config = config_element("", "", {"format" => "none"})
 
-      path = "#{TMP_DIR}/tail.txt"
+      path = "#{@tmp_dir}/tail.txt"
       ino = 1
       pos = 1234
-      File.open("#{TMP_DIR}/tail.pos", "wb") {|f|
+      File.open("#{@tmp_dir}/tail.pos", "wb") {|f|
         f.puts ("%s\t%016x\t%016x\n" % [path, pos, ino])
       }
 
       d = create_driver(config)
       d.run do
-        pos_file = File.open("#{TMP_DIR}/tail.pos", "r")
+        pos_file = File.open("#{@tmp_dir}/tail.pos", "r")
         pos_file.pos = 0
         assert_equal([], pos_file.readlines)
       end
@@ -2017,8 +2036,8 @@ def test_should_remove_deleted_file
 
     def test_should_mark_file_unwatched_after_limit_recently_modified_and_rotate_wait
       config = config_element("ROOT", "", {
-          "path" => "#{TMP_DIR}/tail.txt*",
-          "pos_file" => "#{TMP_DIR}/tail.pos",
+          "path" => "#{@tmp_dir}/tail.txt*",
+          "pos_file" => "#{@tmp_dir}/tail.pos",
           "tag" => "t1",
           "rotate_wait" => "1s",
           "refresh_interval" => "1s",
@@ -2030,14 +2049,14 @@ def test_should_mark_file_unwatched_after_limit_recently_modified_and_rotate_wai
 
       d = create_driver(config, false)
 
-      File.open("#{TMP_DIR}/tail.txt", "wb") {|f|
+      File.open("#{@tmp_dir}/tail.txt", "wb") {|f|
         f.puts "test1"
         f.puts "test2"
       }
-      target_info = create_target_info("#{TMP_DIR}/tail.txt")
+      target_info = create_target_info("#{@tmp_dir}/tail.txt")
 
       d.run(expect_emits: 1, shutdown: false) do
-        File.open("#{TMP_DIR}/tail.txt", "ab") {|f| f.puts "test3\n"}
+        File.open("#{@tmp_dir}/tail.txt", "ab") {|f| f.puts "test3\n"}
       end
 
 
@@ -2055,8 +2074,8 @@ def test_should_mark_file_unwatched_after_limit_recently_modified_and_rotate_wai
 
     def test_should_read_from_head_on_file_renaming_with_star_in_pattern
       config = config_element("ROOT", "", {
-          "path" => "#{TMP_DIR}/tail.txt*",
-          "pos_file" => "#{TMP_DIR}/tail.pos",
+          "path" => "#{@tmp_dir}/tail.txt*",
+          "pos_file" => "#{@tmp_dir}/tail.pos",
           "tag" => "t1",
           "rotate_wait" => "10s",
           "refresh_interval" => "1s",
@@ -2068,14 +2087,14 @@ def test_should_read_from_head_on_file_renaming_with_star_in_pattern
 
       d = create_driver(config, false)
 
-      File.open("#{TMP_DIR}/tail.txt", "wb") {|f|
+      File.open("#{@tmp_dir}/tail.txt", "wb") {|f|
         f.puts "test1"
         f.puts "test2"
       }
 
       d.run(expect_emits: 2, shutdown: false) do
-        File.open("#{TMP_DIR}/tail.txt", "ab") {|f| f.puts "test3\n"}
-        FileUtils.move("#{TMP_DIR}/tail.txt", "#{TMP_DIR}/tail.txt1")
+        File.open("#{@tmp_dir}/tail.txt", "ab") {|f| f.puts "test3\n"}
+        FileUtils.move("#{@tmp_dir}/tail.txt", "#{@tmp_dir}/tail.txt1")
       end
 
       events = d.events
@@ -2084,20 +2103,20 @@ def test_should_read_from_head_on_file_renaming_with_star_in_pattern
     end
 
     def test_should_not_read_from_head_on_rotation_when_watching_inodes
-      config = COMMON_FOLLOW_INODE_CONFIG
+      config = common_follow_inode_config
 
       d = create_driver(config, false)
 
-      File.open("#{TMP_DIR}/tail.txt", "wb") {|f|
+      File.open("#{@tmp_dir}/tail.txt", "wb") {|f|
         f.puts "test1"
         f.puts "test2"
       }
 
       d.run(expect_emits: 1, shutdown: false) do
-        File.open("#{TMP_DIR}/tail.txt", "ab") {|f| f.puts "test3\n"}
+        File.open("#{@tmp_dir}/tail.txt", "ab") {|f| f.puts "test3\n"}
       end
 
-      FileUtils.move("#{TMP_DIR}/tail.txt", "#{TMP_DIR}/tail.txt1")
+      FileUtils.move("#{@tmp_dir}/tail.txt", "#{@tmp_dir}/tail.txt1")
       Timecop.travel(Time.now + 10) do
         sleep 2
         events = d.events
@@ -2108,23 +2127,23 @@ def test_should_not_read_from_head_on_rotation_when_watching_inodes
     end
 
     def test_should_mark_file_unwatched_if_same_name_file_created_with_different_inode
-      config = COMMON_FOLLOW_INODE_CONFIG
+      config = common_follow_inode_config
 
       d = create_driver(config, false)
 
-      File.open("#{TMP_DIR}/tail.txt", "wb") {|f|
+      File.open("#{@tmp_dir}/tail.txt", "wb") {|f|
         f.puts "test1"
         f.puts "test2"
       }
-      target_info = create_target_info("#{TMP_DIR}/tail.txt")
+      target_info = create_target_info("#{@tmp_dir}/tail.txt")
 
       d.run(expect_emits: 2, shutdown: false) do
-        File.open("#{TMP_DIR}/tail.txt", "ab") {|f| f.puts "test3\n"}
-        cleanup_file("#{TMP_DIR}/tail.txt")
-        File.open("#{TMP_DIR}/tail.txt", "wb") {|f| f.puts "test4\n"}
+        File.open("#{@tmp_dir}/tail.txt", "ab") {|f| f.puts "test3\n"}
+        cleanup_file("#{@tmp_dir}/tail.txt")
+        File.open("#{@tmp_dir}/tail.txt", "wb") {|f| f.puts "test4\n"}
       end
 
-      new_target_info = create_target_info("#{TMP_DIR}/tail.txt")
+      new_target_info = create_target_info("#{@tmp_dir}/tail.txt")
 
       pos_file = d.instance.instance_variable_get(:@pf)
 
@@ -2140,7 +2159,7 @@ def test_should_mark_file_unwatched_if_same_name_file_created_with_different_ino
 
     def test_should_close_watcher_after_rotate_wait
       now = Time.now
-      config = COMMON_FOLLOW_INODE_CONFIG + config_element('', '', {"rotate_wait" => "1s", "limit_recently_modified" => "1s"})
+      config = common_follow_inode_config + config_element('', '', {"rotate_wait" => "1s", "limit_recently_modified" => "1s"})
 
       d = create_driver(config, false)
       d.instance.instance_eval do
@@ -2153,11 +2172,11 @@ def test_should_close_watcher_after_rotate_wait
         @metrics = Fluent::Plugin::TailInput::MetricsInfo.new(opened_file_metrics, closed_file_metrics, rotated_file_metrics)
       end
 
-      File.open("#{TMP_DIR}/tail.txt", "wb") {|f|
+      File.open("#{@tmp_dir}/tail.txt", "wb") {|f|
         f.puts "test1"
         f.puts "test2"
       }
-      target_info = create_target_info("#{TMP_DIR}/tail.txt")
+      target_info = create_target_info("#{@tmp_dir}/tail.txt")
       mock.proxy(Fluent::Plugin::TailInput::TailWatcher).new(target_info, anything, anything, true, true, anything, nil, anything, anything).once
       d.run(shutdown: false)
       assert d.instance.instance_variable_get(:@tails)[target_info.path]
@@ -2173,26 +2192,26 @@ def test_should_close_watcher_after_rotate_wait
 
     def test_should_create_new_watcher_for_new_file_with_same_name
       now = Time.now
-      config = COMMON_FOLLOW_INODE_CONFIG + config_element('', '', {"limit_recently_modified" => "2s"})
+      config = common_follow_inode_config + config_element('', '', {"limit_recently_modified" => "2s"})
 
       d = create_driver(config, false)
 
-      File.open("#{TMP_DIR}/tail.txt", "wb") {|f|
+      File.open("#{@tmp_dir}/tail.txt", "wb") {|f|
         f.puts "test1"
         f.puts "test2"
       }
-      path_ino = create_target_info("#{TMP_DIR}/tail.txt")
+      path_ino = create_target_info("#{@tmp_dir}/tail.txt")
 
       d.run(expect_emits: 1, shutdown: false) do
-        File.open("#{TMP_DIR}/tail.txt", "ab") {|f| f.puts "test3\n"}
+        File.open("#{@tmp_dir}/tail.txt", "ab") {|f| f.puts "test3\n"}
       end
 
-      cleanup_file("#{TMP_DIR}/tail.txt")
-      File.open("#{TMP_DIR}/tail.txt", "wb") {|f|
+      cleanup_file("#{@tmp_dir}/tail.txt")
+      File.open("#{@tmp_dir}/tail.txt", "wb") {|f|
         f.puts "test3"
         f.puts "test4"
       }
-      new_path_ino = create_target_info("#{TMP_DIR}/tail.txt")
+      new_path_ino = create_target_info("#{@tmp_dir}/tail.txt")
 
       Timecop.travel(now + 10) do
         sleep 3
@@ -2210,19 +2229,19 @@ def test_should_create_new_watcher_for_new_file_with_same_name
     end
 
     def test_truncate_file_with_follow_inodes
-      config = COMMON_FOLLOW_INODE_CONFIG
+      config = common_follow_inode_config
 
       d = create_driver(config, false)
 
-      File.open("#{TMP_DIR}/tail.txt", "wb") {|f|
+      File.open("#{@tmp_dir}/tail.txt", "wb") {|f|
         f.puts "test1"
         f.puts "test2"
       }
 
       d.run(expect_emits: 3, shutdown: false) do
-        File.open("#{TMP_DIR}/tail.txt", "ab") {|f| f.puts "test3\n"}
+        File.open("#{@tmp_dir}/tail.txt", "ab") {|f| f.puts "test3\n"}
         sleep 2
-        File.open("#{TMP_DIR}/tail.txt", "w+b") {|f| f.puts "test4\n"}
+        File.open("#{@tmp_dir}/tail.txt", "w+b") {|f| f.puts "test4\n"}
       end
 
       events = d.events
@@ -2236,15 +2255,15 @@ def test_truncate_file_with_follow_inodes
 
     # issue #3464
     def test_should_replace_target_info
-      File.open("#{TMP_DIR}/tail.txt", "wb") {|f|
+      File.open("#{@tmp_dir}/tail.txt", "wb") {|f|
         f.puts "test1\n"
       }
-      target_info = create_target_info("#{TMP_DIR}/tail.txt")
+      target_info = create_target_info("#{@tmp_dir}/tail.txt")
       inodes = []
 
       config = config_element("ROOT", "", {
-                                "path" => "#{TMP_DIR}/tail.txt*",
-                                "pos_file" => "#{TMP_DIR}/tail.pos",
+                                "path" => "#{@tmp_dir}/tail.txt*",
+                                "pos_file" => "#{@tmp_dir}/tail.pos",
                                 "tag" => "t1",
                                 "refresh_interval" => "60s",
                                 "read_from_head" => "true",
@@ -2262,8 +2281,8 @@ def test_should_replace_target_info
         end
         assert_equal([target_info.ino], inodes)
 
-        cleanup_file("#{TMP_DIR}/tail.txt")
-        File.open("#{TMP_DIR}/tail.txt", "wb") {|f| f.puts "test2\n"}
+        cleanup_file("#{@tmp_dir}/tail.txt")
+        File.open("#{@tmp_dir}/tail.txt", "wb") {|f| f.puts "test2\n"}
 
         while d.events.size < 2 do
           sleep 0.1
@@ -2271,7 +2290,7 @@ def test_should_replace_target_info
         inodes = d.instance.instance_variable_get(:@tails).values.collect do |tw|
           tw.ino
         end
-        new_target_info = create_target_info("#{TMP_DIR}/tail.txt")
+        new_target_info = create_target_info("#{@tmp_dir}/tail.txt")
         assert_not_equal(target_info.ino, new_target_info.ino)
         assert_equal([new_target_info.ino], inodes)
       end
@@ -2280,7 +2299,7 @@ def test_should_replace_target_info
 
   sub_test_case "tail_path" do
     def test_tail_path_with_singleline
-      File.open("#{TMP_DIR}/tail.txt", "wb") {|f|
+      File.open("#{@tmp_dir}/tail.txt", "wb") {|f|
         f.puts "test1"
         f.puts "test2"
       }
@@ -2288,7 +2307,7 @@ def test_tail_path_with_singleline
       d = create_driver(SINGLE_LINE_CONFIG + config_element("", "", { "path_key" => "path" }))
 
       d.run(expect_emits: 1) do
-        File.open("#{TMP_DIR}/tail.txt", "ab") {|f|
+        File.open("#{@tmp_dir}/tail.txt", "ab") {|f|
           f.puts "test3"
           f.puts "test4"
         }
@@ -2297,12 +2316,12 @@ def test_tail_path_with_singleline
       events = d.events
       assert_equal(true, events.length > 0)
       events.each do |emit|
-        assert_equal("#{TMP_DIR}/tail.txt", emit[2]["path"])
+        assert_equal("#{@tmp_dir}/tail.txt", emit[2]["path"])
       end
     end
 
     def test_tail_path_with_multiline_with_firstline
-      File.open("#{TMP_DIR}/tail.txt", "wb") { |f| }
+      File.open("#{@tmp_dir}/tail.txt", "wb") { |f| }
 
       config = config_element("", "", {
                                 "path_key" => "path",
@@ -2312,7 +2331,7 @@ def test_tail_path_with_multiline_with_firstline
                               })
       d = create_driver(config)
       d.run(expect_emits: 1) do
-        File.open("#{TMP_DIR}/tail.txt", "ab") { |f|
+        File.open("#{@tmp_dir}/tail.txt", "ab") { |f|
           f.puts "f test1"
           f.puts "s test2"
           f.puts "f test3"
@@ -2327,12 +2346,12 @@ def test_tail_path_with_multiline_with_firstline
       events = d.events
       assert_equal(4, events.length)
       events.each do |emit|
-        assert_equal("#{TMP_DIR}/tail.txt", emit[2]["path"])
+        assert_equal("#{@tmp_dir}/tail.txt", emit[2]["path"])
       end
     end
 
     def test_tail_path_with_multiline_without_firstline
-      File.open("#{TMP_DIR}/tail.txt", "wb") { |f| }
+      File.open("#{@tmp_dir}/tail.txt", "wb") { |f| }
 
       config = config_element("", "", {
                                 "path_key" => "path",
@@ -2343,7 +2362,7 @@ def test_tail_path_with_multiline_without_firstline
                               })
       d = create_driver(config)
       d.run(expect_emits: 1) do
-        File.open("#{TMP_DIR}/tail.txt", "ab") { |f|
+        File.open("#{@tmp_dir}/tail.txt", "ab") { |f|
           f.puts "foo 1"
           f.puts "bar 1"
           f.puts "baz 1"
@@ -2353,7 +2372,7 @@ def test_tail_path_with_multiline_without_firstline
       events = d.events
       assert(events.length > 0)
       events.each do |emit|
-        assert_equal("#{TMP_DIR}/tail.txt", emit[2]["path"])
+        assert_equal("#{@tmp_dir}/tail.txt", emit[2]["path"])
       end
     end
 
@@ -2361,7 +2380,7 @@ def test_tail_path_with_multiline_with_multiple_paths
       if ENV["APPVEYOR"] && Fluent.windows?
         omit "This testcase is unstable on AppVeyor."
       end
-      files = ["#{TMP_DIR}/tail1.txt", "#{TMP_DIR}/tail2.txt"]
+      files = ["#{@tmp_dir}/tail1.txt", "#{@tmp_dir}/tail2.txt"]
       files.each { |file| File.open(file, "wb") { |f| } }
 
       config = config_element("", "", {
@@ -2395,20 +2414,20 @@ def test_tail_path_with_multiline_with_multiple_paths
 
   def test_limit_recently_modified
     now = Time.new(2010, 1, 2, 3, 4, 5)
-    FileUtils.touch("#{TMP_DIR}/tail_unwatch.txt", mtime: (now - 3601))
-    FileUtils.touch("#{TMP_DIR}/tail_watch1.txt", mtime: (now - 3600))
-    FileUtils.touch("#{TMP_DIR}/tail_watch2.txt", mtime: now)
+    FileUtils.touch("#{@tmp_dir}/tail_unwatch.txt", mtime: (now - 3601))
+    FileUtils.touch("#{@tmp_dir}/tail_watch1.txt", mtime: (now - 3600))
+    FileUtils.touch("#{@tmp_dir}/tail_watch2.txt", mtime: now)
 
     config = config_element('', '', {
       'tag' => 'tail',
-      'path' => "#{TMP_DIR}/*.txt",
+      'path' => "#{@tmp_dir}/*.txt",
       'format' => 'none',
       'limit_recently_modified' => '3600s'
     })
 
     expected_files = [
-      create_target_info("#{TMP_DIR}/tail_watch1.txt"),
-      create_target_info("#{TMP_DIR}/tail_watch2.txt")
+      create_target_info("#{@tmp_dir}/tail_watch1.txt"),
+      create_target_info("#{@tmp_dir}/tail_watch2.txt")
     ]
 
     Timecop.freeze(now) do
@@ -2418,7 +2437,7 @@ def test_limit_recently_modified
   end
 
   def test_skip_refresh_on_startup
-    FileUtils.touch("#{TMP_DIR}/tail.txt")
+    FileUtils.touch("#{@tmp_dir}/tail.txt")
     config = config_element('', '', {
                               'format' => 'none',
                               'refresh_interval' => 1,
@@ -2433,7 +2452,7 @@ def test_skip_refresh_on_startup
   end
 
   def test_ENOENT_error_after_setup_watcher
-    path = "#{TMP_DIR}/tail.txt"
+    path = "#{@tmp_dir}/tail.txt"
     FileUtils.touch(path)
     config = config_element('', '', {
                               'format' => 'none',
@@ -2458,10 +2477,10 @@ def test_ENOENT_error_after_setup_watcher
 
   def test_EACCES_error_after_setup_watcher
     omit "Cannot test with root user" if Process::UID.eid == 0
-    path = "#{TMP_DIR}/noaccess/tail.txt"
+    path = "#{@tmp_dir}/noaccess/tail.txt"
     begin
-      FileUtils.mkdir_p("#{TMP_DIR}/noaccess")
-      FileUtils.chmod(0755, "#{TMP_DIR}/noaccess")
+      FileUtils.mkdir_p("#{@tmp_dir}/noaccess")
+      FileUtils.chmod(0755, "#{@tmp_dir}/noaccess")
       FileUtils.touch(path)
       config = config_element('', '', {
                                 'tag' => "tail",
@@ -2470,7 +2489,7 @@ def test_EACCES_error_after_setup_watcher
                               })
       d = create_driver(config, false)
       mock.proxy(d.instance).existence_path do |hash|
-        FileUtils.chmod(0000, "#{TMP_DIR}/noaccess")
+        FileUtils.chmod(0000, "#{@tmp_dir}/noaccess")
         hash
       end.twice
       assert_nothing_raised do
@@ -2481,14 +2500,14 @@ def test_EACCES_error_after_setup_watcher
     end
   ensure
     d.instance_shutdown if d && d.instance
-    if File.exist?("#{TMP_DIR}/noaccess")
-      FileUtils.chmod(0755, "#{TMP_DIR}/noaccess")
-      FileUtils.rm_rf("#{TMP_DIR}/noaccess")
+    if File.exist?("#{@tmp_dir}/noaccess")
+      FileUtils.chmod(0755, "#{@tmp_dir}/noaccess")
+      FileUtils.rm_rf("#{@tmp_dir}/noaccess")
     end
   end unless Fluent.windows?
 
   def test_EACCES
-    path = "#{TMP_DIR}/tail.txt"
+    path = "#{@tmp_dir}/tail.txt"
     FileUtils.touch(path)
     config = config_element('', '', {
                               'format' => 'none',
@@ -2506,7 +2525,7 @@ def test_EACCES
   end
 
   def test_shutdown_timeout
-    File.open("#{TMP_DIR}/tail.txt", "wb") do |f|
+    File.open("#{@tmp_dir}/tail.txt", "wb") do |f|
       (1024 * 1024 * 5).times do
         f.puts "{\"test\":\"fizzbuzz\"}"
       end
@@ -2539,7 +2558,7 @@ def test_shutdown_timeout
     def test_lines_collected_with_no_throttling(data)
       file, num_lines, msg = data
 
-      pattern = "/^#{TMP_DIR}\/(?<file>.+)\.log$/"
+      pattern = "/^#{@tmp_dir}\/(?<file>.+)\.log$/"
       rule = create_rule_directive({
         "file" => "/test.*/",
       }, -1)
@@ -2548,7 +2567,7 @@ def test_lines_collected_with_no_throttling(data)
 
       conf = ROOT_CONFIG + group + path_element + CONFIG_READ_FROM_HEAD + SINGLE_LINE_CONFIG
 
-      File.open("#{TMP_DIR}/#{file}", 'wb') do |f|
+      File.open("#{@tmp_dir}/#{file}", 'wb') do |f|
         num_lines.times do
           f.puts "#{msg}\n"
         end
@@ -2589,10 +2608,10 @@ def test_lines_collected_with_no_throttling(data)
         "podname"=> "/podname.+/",
       }, limit)
       path_element = create_path_element(file)
-      conf = ROOT_CONFIG + create_group_directive(TAILING_GROUP_PATTERN, "#{rate_period}s", rule) + path_element + SINGLE_LINE_CONFIG + CONFIG_READ_FROM_HEAD
+      conf = ROOT_CONFIG + create_group_directive(tailing_group_pattern, "#{rate_period}s", rule) + path_element + SINGLE_LINE_CONFIG + CONFIG_READ_FROM_HEAD
 
       d = create_driver(conf, false)
-      file_path = "#{TMP_DIR}/#{file}"
+      file_path = "#{@tmp_dir}/#{file}"
 
       File.open(file_path, 'wb') do |f|
         num_lines.times do