(WIP)Support expernal command file(graceful reloadable)

fluent.conf

@@ -0,0 +1,25 @@
+<source>
+  type exec
+  command echo http://example.com
+  keys uri
+  tag example
+  run_interval 1s
+</source>
+
+<match example.**>
+  type copy
+  <store>
+  type ruby_one_liner
+  require_libs open-uri
+  command  $log.warn "oneline"
+  run_interval 1
+  any_config 2
+  </store>
+  <store>
+  type ruby_one_liner
+  require_libs open-uri
+  commandfile hoge.rb
+  run_interval 1
+  any_config 2
+  </store>
+</match>

hoge.rb

@@ -0,0 +1 @@
+$log.warn "BaA"

lib/fluent/plugin/out_ruby_one_liner.rb

@@ -3,7 +3,8 @@ class Fluent::RubyOneLinerOutput < Fluent::Output
     Fluent::Plugin.register_output('ruby_one_liner', self)
 
     config_param :require_libs, :string,:default => ''
-    config_param :command, :string
+    config_param :command, :string, :default => ''
+    config_param :commandfile, :string, :default => ''
     config_param :run_interval, :integer
 
     def initialize
@@ -12,12 +13,25 @@ def initialize
 
     def configure(config)
       super
-
+      
       libs = @require_libs.split(',')
       libs.each {|lib| require lib}
 
+      Signal.trap :INT do
+        $log.warn 'out_ruby_one_liner: reload commandfile start'
+        reload_commandfile!
+        $log.warn 'out_ruby_one_liner: reload commandfile end'
+      end
+
+      command = if !@command.empty?
+        @command
+      elsif !@commandfile.empty?
+        open(@commandfile).read
+      else
+        raise ConfigError, "out_ruby_one_liner: command or commandfile is required to be set."    
+      end
       @config = config
-      @lambda = eval("lambda {|tag, time, record| #{@command}}")
+      @lambda = eval("lambda {|tag, time, record| #{command}}")
       @q = Queue.new
     end
 
@@ -50,6 +64,13 @@ def emit(tag, es, chain)
 
     private
 
+    def reload_commandfile!
+      command = open(@commandfile).read
+      Thread.kill(@thread)
+      @lambda = eval("lambda {|tag, time, record| #{command}}")
+      @thread = Thread.new(&method(:run))
+    end
+
     def run
       loop do
         param = @q.pop