Remove blank lines; add information to defaults

playbooks/roles/hadoop_common/defaults/main.yml

@@ -96,6 +96,15 @@ HDFS_SITE_DEFAULT_CONFIG:
 #   yarn.nodemanager.resource.memory-mb: 2048
 #   yarn.nodemanager.vmem-pmem-ratio: 2.1
 
+#
+# Variables override the stock configuration for entry into
+# the following files. Ensure that you use unambiguous
+# string literals to avoid any confusion:
+#     core-site.xml
+#     hdfs-site.xml
+#     mapred-site.xml
+#     yarn-site.xml
+#
 mapred_site_config: {}
 yarn_site_config: {}
 HADOOP_CORE_SITE_EXTRA_CONFIG: {}

playbooks/roles/hadoop_common/templates/core-site.xml.j2

 {% do HADOOP_CORE_SITE_DEFAULT_CONFIG.update(HADOOP_CORE_SITE_EXTRA_CONFIG) %}
 <?xml version="1.0"?>
 <?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
-
 <!-- Put site-specific property overrides in this file. -->
-
 <configuration>
-
 {% for key, value in HADOOP_CORE_SITE_DEFAULT_CONFIG.iteritems() %}
   <property>
     <name>{{ key }}</name>
     <value>{{ value }}</value>
   </property>
-
 {% endfor %}
-</configuration>
\ No newline at end of file
+</configuration>

playbooks/roles/hadoop_common/templates/hdfs-site.xml.j2

 {% do HDFS_SITE_DEFAULT_CONFIG.update(HDFS_SITE_EXTRA_CONFIG) %}
 <?xml version="1.0"?>
 <?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
-
 <configuration>
-
 {% for key, value in HDFS_SITE_DEFAULT_CONFIG.iteritems() %}
   <property>
     <name>{{ key }}</name>
     <value>{{ value }}</value>
   </property>
-
 {% endfor %}
-</configuration>
\ No newline at end of file
+</configuration>

playbooks/roles/hadoop_common/templates/mapred-site.xml.j2

 {% do MAPRED_SITE_DEFAULT_CONFIG.update(mapred_site_config) %}
 <?xml version="1.0"?>
 <?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
-
 <configuration>
-
 {% for key, value in MAPRED_SITE_DEFAULT_CONFIG.iteritems() %}
   <property>
     <name>{{ key }}</name>
     <value>{{ value }}</value>
   </property>
-
 {% endfor %}
 </configuration>

playbooks/roles/hadoop_common/templates/yarn-site.xml.j2

 {% do YARN_SITE_DEFAULT_CONFIG.update(yarn_site_config) %}
 <?xml version="1.0"?>
-
 <configuration>
-
 {% for key, value in YARN_SITE_DEFAULT_CONFIG.iteritems() %}
   <property>
     <name>{{ key }}</name>
     <value>{{ value }}</value>
   </property>
-
 {% endfor %}
 </configuration>

playbooks/roles/hive/templates/hive-site.xml.j2

 {% do HIVE_SITE_DEFAULT_CONFIG.update(HIVE_SITE_EXTRA_CONFIG) %}
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
-
 <configuration>
-
 {% for key, value in HIVE_SITE_DEFAULT_CONFIG.iteritems() %}
   <property>
     <name>{{ key }}</name>
     <value>{{ value }}</value>
   </property>
-
 {% endfor %}
 </configuration>