in_tail: Add always option for handle most of the glob patterns

I'm, not sure this commit makes to be able to handle the all of the glob
patterns but mostly seems OK.

Signed-off-by: Hiroshi Hatake <[email protected]>

lib/fluent/plugin/in_tail.rb

@@ -64,8 +64,8 @@ def initialize
     config_param :path, :string
     desc 'path delimiter used for spliting path config'
     config_param :path_delimiter, :string, default: ','
-    desc 'Choose using glob patterns. Adding whether a capability to handle [] and ? or not.'
-    config_param :glob_policy, :enum, list: [:backward_compatible, :extended], default: :backward_compatible
+    desc 'Choose using glob patterns. Adding capabilities to handle [] and ?, and {}.'
+    config_param :glob_policy, :enum, list: [:backward_compatible, :extended, :always], default: :backward_compatible
     desc 'The tag of the event.'
     config_param :tag, :string
     desc 'The paths to exclude the files from watcher list.'
@@ -142,6 +142,10 @@ def configure(conf)
         raise Fluent::ConfigError, "either of enable_watch_timer or enable_stat_watcher must be true"
       end
 
+      if @glob_policy == :always && @path_delimiter == ','
+        raise Fluent::ConfigError, "cannot use glob_policy as always with the default path_delimitor: `,\""
+      end
+
       if RESERVED_CHARS.include?(@path_delimiter)
         rc = RESERVED_CHARS.join(', ')
         raise Fluent::ConfigError, "#{rc} are reserved words: #{@path_delimiter}"
@@ -288,7 +292,9 @@ def have_read_capability?
     # Curly braces is not supported for now because the default delimiter of path is ",".
     # This should be collided for wildcard pattern for curly braces.
     def use_glob?(path)
-      if @glob_policy == :extended
+      if @glob_policy == :always
+        path.include?('*') || path.include?('?') || /\[.*\]/.match(path) || /\{.*,.*\}/.match(path)
+      elsif @glob_policy == :extended
         path.include?('*') || path.include?('?') || /\[.*\]/.match(path)
       elsif @glob_policy == :backward_compatible
         path.include?('*')

test/plugin/test_in_tail.rb

@@ -1600,6 +1600,43 @@ def ex_config_with_brackets
                    })
     end
 
+    def test_config_with_always_with_default_delimiter
+      assert_raise(Fluent::ConfigError) do
+        config = config_element("", "", {
+                         "tag" => "tail",
+                         "path" => "test/plugin/data/log_numeric/[0-1][2-4].log",
+                         "format" => "none",
+                         "pos_file" => "#{@tmp_dir}/tail.pos",
+                         "read_from_head" => true,
+                         "refresh_interval" => 30,
+                         "glob_policy" => "always",
+                         "rotate_wait" => "#{EX_ROTATE_WAIT}s",
+                         "follow_inodes" => "#{EX_FOLLOW_INODES}",
+                       })
+
+        create_driver(config, false).instance
+      end
+    end
+
+    def test_config_with_always_with_custom_delimiter
+      assert_nothing_raised do
+        config = config_element("", "", {
+                         "tag" => "tail",
+                         "path" => "test/plugin/data/log_numeric/[0-1][2-4].log",
+                         "format" => "none",
+                         "pos_file" => "#{@tmp_dir}/tail.pos",
+                         "read_from_head" => true,
+                         "refresh_interval" => 30,
+                         "glob_policy" => "always",
+                         "path_delimiter" => "|",
+                         "rotate_wait" => "#{EX_ROTATE_WAIT}s",
+                         "follow_inodes" => "#{EX_FOLLOW_INODES}",
+                       })
+
+        create_driver(config, false).instance
+      end
+    end
+
     def test_expand_paths_with_brackets
       expanded_paths = [
         create_target_info('test/plugin/data/log_numeric/01.log'),