in_tail: Simplify the error handling while contructing a watcher

Signed-off-by: Takuro Ashie <ashie@clear-code.com>
fluent · Aug 26, 2021 · 5b3dd1c · 5b3dd1c
1 parent 9b9eced
commit 5b3dd1c
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Showing 2 changed files with 21 additions and 26 deletions.
diff --git a/lib/fluent/plugin/in_tail.rb b/lib/fluent/plugin/in_tail.rb
@@ -406,35 +406,28 @@ def setup_watcher(target_info, pe)
 
     def construct_watcher(target_info)
       path = target_info.path
+
+      begin
+        ino = Fluent::FileWrapper.stat(path).ino
+      rescue Errno::ENOENT, Errno::EACCES
+        $log.warn "stat() for #{path} failed. Continuing without tailing it."
+        return
+      end
+
       pe = nil
       if @pf
         pe = @pf[target_info]
-        if @read_from_head && pe.read_inode.zero?
-          begin
-            pe.update(Fluent::FileWrapper.stat(path).ino, 0)
-          rescue Errno::ENOENT, Errno::EACCES
-            $log.warn "stat() for #{path} failed. Continuing without tailing it."
-          end
-        end
+        pe.update(ino, 0) if @read_from_head && pe.read_inode.zero?
       end
 
       begin
         tw = setup_watcher(target_info, pe)
+        @tails[path] = tw
+        tw.on_notify
       rescue WatcherSetupError => e
         log.warn "Skip #{path} because unexpected setup error happens: #{e}"
         return
       end
-
-      begin
-        target_info = TargetInfo.new(path, Fluent::FileWrapper.stat(path).ino)
-        @tails[path] = tw
-        tw.on_notify
-      rescue Errno::ENOENT, Errno::EACCES => e
-        $log.warn "stat() for #{path} failed with #{e.class.name}. Drop tail watcher for now."
-        # explicitly detach and unwatch watcher `tw`.
-        tw.unwatched = true
-        detach_watcher(tw, target_info.ino, false)
-      end
     end
 
     def start_watchers(targets_info)

diff --git a/test/plugin/test_in_tail.rb b/test/plugin/test_in_tail.rb
@@ -2171,14 +2171,15 @@ def test_ENOENT_error_after_setup_watcher
                               'format' => 'none',
                             })
     d = create_driver(config)
-    mock.proxy(d.instance).setup_watcher(anything, anything) do |tw|
+    mock.proxy(d.instance).existence_path do |hash|
       cleanup_file(path)
-      tw
-    end
+      hash
+    end.at_least(1)
     assert_nothing_raised do
       d.run(shutdown: false) {}
     end
-    assert($log.out.logs.any?{|log| log.include?("stat() for #{path} failed with Errno::ENOENT. Drop tail watcher for now.\n") })
+    assert($log.out.logs.any?{|log| log.include?("stat() for #{path} failed. Continuing without tailing it.\n") },
+           $log.out.logs.join("\n"))
   ensure
     d.instance_shutdown if d && d.instance
   end
@@ -2196,14 +2197,15 @@ def test_EACCES_error_after_setup_watcher
                                 'format' => 'none',
                               })
       d = create_driver(config, false)
-      mock.proxy(d.instance).setup_watcher(anything, anything) do |tw|
+      mock.proxy(d.instance).existence_path do |hash|
         FileUtils.chmod(0000, "#{TMP_DIR}/noaccess")
-        tw
-      end
+        hash
+      end.at_least(1)
       assert_nothing_raised do
         d.run(shutdown: false) {}
       end
-      assert($log.out.logs.any?{|log| log.include?("stat() for #{path} failed with Errno::EACCES. Drop tail watcher for now.\n") })
+      assert($log.out.logs.any?{|log| log.include?("stat() for #{path} failed. Continuing without tailing it.\n") },
+             $log.out.logs.join("\n"))
     end
   ensure
     d.instance_shutdown if d && d.instance