```ruby
#
# Cookbook Name:: cdap
# Recipe:: init
#
# Copyright © 2013-2014 Cask Data, 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.
#

include_recipe 'cdap::default'

# We also need the configuration, so we can run HDFS commands
execute 'initaction-create-hdfs-cdap-dir' do
  not_if  "hdfs dfs -test -d #{node['cdap']['cdap_site']['hdfs.namespace']}", :user => 'hdfs'
  command "hdfs dfs -mkdir -p #{node['cdap']['cdap_site']['hdfs.namespace']} && hdfs dfs -chown yarn #{node['cdap']['cdap_site']['hdfs.namespace']}"
  timeout 300
  user 'hdfs'
  group 'hdfs'
end
```

Use attribute versus hard-coding yarn
user
```ruby
#
# Cookbook Name:: cdap
# Recipe:: init
#
# Copyright © 2013-2014 Cask Data, 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.
#

include_recipe 'cdap::default'

# We also need the configuration, so we can run HDFS commands
execute 'initaction-create-hdfs-cdap-dir' do
  not_if  "hdfs dfs -test -d #{node['cdap']['cdap_site']['hdfs.namespace']}", :user => 'hdfs'
  command "hdfs dfs -mkdir -p #{node['cdap']['cdap_site']['hdfs.namespace']} && hdfs dfs -chown #{node['cdap']['cdap_site']['hdfs.user']} #{node['cdap']['cdap_site']['hdfs.namespace']}"
  timeout 300
  user 'hdfs'
  group 'hdfs'
end
```
assistant