is_master in is_master-1.1.0

- old
+ new
@@ -1,19 +1,37 @@
 #!/usr/bin/env ruby
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
 require 'socket'
 
 if ARGV.length < 2
   puts 'is_master execute a command when it determine that server is master'
-  puts "Usage: #{$PROGRAM_NAME} VIP COMMAND"
-  puts '  VIP - IP address expected to be master'
+  puts "Usage: #{$PROGRAM_NAME} [VIP|FILE] COMMAND"
+  puts '  VIP     - IP address expected to be master'
+  puts '  FILE    - File expected to be master'
   puts '  COMMAND - Command to execute if host is master'
   exit 2
 end
 
-vip = ARGV[0]
-command = ARGV[1..-1].join(' ')
+expected = ARGV[0]
+command  = ARGV[1..-1].join(' ')
 
-if Socket.ip_address_list.map(&:ip_address).include?(vip)
+if Socket.ip_address_list.map(&:ip_address).include?(expected) || File.exist?(expected)
   Kernel.exec(command)
 else
   puts 'OK - I am slave, i going to sleep'
 end