```ruby
# -*- coding: utf-8 -*-
# Copyright 2014 TIS Inc.
#
# Licensed 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.


module CloudConductor
  module CommonHelper
    def server_info(role)
      all_servers = node['cloudconductor']['servers']
      servers = all_servers.select do |_hostname, server|
        server[:roles].include?(role)
      end
      result = servers.map do |hostname, server|
        copy = Hash.new.merge(server)
        copy[:hostname] = hostname
        copy
      end
      result
    end
  end
end
```

Modify to with indifferent access
user
```ruby
# -*- coding: utf-8 -*-
# Copyright 2014 TIS Inc.
#
# Licensed 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 'active_support'
require 'active_support/core_ext'

module CloudConductor
  module CommonHelper
    def server_info(role)
      all_servers = node['cloudconductor']['servers']
      servers = all_servers.to_hash.select do |_hostname, server|
        server['roles'].include?(role)
      end
      result = servers.map do |hostname, server|
        server[:hostname] = hostname
        server.with_indifferent_access
      end
      result
    end
  end
end
```
assistant